为什么内存只有十二G，买套套是怎么和店员说明明说有十六G
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时间：2017-12-17 17:05
为什么内存只有十二G，店员明明说有十六G_百度知道
为什么内存只有十二G，店员明明说有十六G
我有更好的答案
手机的话是正常的，系统要占用一部分存储的。可以说手机全是这样的。如果是电脑的运行内存，这样就不对了。可以直接卖电脑的问清楚是什么情况。
采纳率：86%
来自团队：
4GB内存条被店家扣留了。
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&&太平洋游戏网 DOTA2 为什么有的说准，有的说不准，其实是自己不会看数据而已，或者数据时间不合适，应该这样看，首先数据不能超过8周，40多天是最合适的，然后就是要有3个数据的，没有3个数据的，一律不能判断，孕囊都是圆柱状的，每个B超师做B超的时候，截面会截取的方位不一样，有的横截面，有的截取竖截面，所以，看图片是长的还是圆的，不能判断男女。
打个比方，比如40*20mm的孕囊，这样根本没有办法判断，表面上看两个数据相差一倍，应该是男孩，错了，因为没有第三个数据，如果是40*40*20，那肯定是男孩，但是如果B超师横截面时，孕囊就成了40*40mm的两个数据，看上去就是圆的了，然后造成了，孕囊是圆的，结果怎么生出了儿子，貌似不准的误导。所以数据一定要有3个。
如果孕囊成等差数列，比如40*30*20，这样就是女孩，但是如果B超师取了40*20的截面，貌似男孩的数据，结果生出了闺女，造成孕囊看男女不准的说法。
亲们自己回家看吧，记住2个数据的话，看不了，因为每个B超师获取孕囊的方位不一样，所以不能判断，有3个数据的，是最好判断的，两个数据差不多，第三个数据比前两个小一倍，那肯定是儿子，如果成递减数据就是女儿。
还有一种情况就是第三个数据小很多的，比如40*38*10，像10比40和38小很多很多，这个也可能是女儿，但80％还是儿子。
有的数据最大数值不是在最前面，不要紧，把3个数据从大到小排好，自己看吧，比如：40*25*39，或者39*25*40，等等，这样都是儿子。 如果有看不懂的，把数据发上来，我来帮你看， 再次声明一下，两个数据的不要发了，看不来的。基本每天早上会回复你们。大家也可以把肚子照片发过来共同识别，准确率相对较高，但需要30周以后的。
楼主发言：1次 发图：0张 | 更多
31X41X20 LZ说的我没看懂~~还是你帮我看看吧~~
lz,你好. 孕7周时B超单,宫腔内可见28*33*40mm妊娠囊 请问,是男孩还是女孩? 谢谢
17*21*9，第47天，谢谢LZ
孕44天的时候 23*16*20麻烦LZ也帮我看看啊，谢谢了
孕51天照的 宫腔内见一胎囊大小 18*09*22 孕57天照的 宫腔内见一胎囊大小 31*17*26
楼主怎么没来了啊 大家都在等着呢 快点回来吧 帮我看看啊
七周28*18*13楼主也给我看看
45天做额BC
按照楼主额介绍 应该是女宝宝 如果真是女宝宝 就太开心了
楼主的这个方法应该还是挺准的，之前在网上介绍的方法都是两个数据的，而我自己的数据是三个的，所以一直不知道该怎么看。 我40天的孕囊：27*24*12，结果生的是小男孩。
你好,我老婆的11周1天的B超单上孕囊大小是21*52*54mm,楼主帮你忙分析下,是男孩女孩?谢谢
我5W+的数据为 18*12*22 帮我看一下是男是女了，谢了
请楼主帮我看一下吧，我是45天做的bc，符合7w+1。bc单上的数据是GS1:30.7MM GS2:17.6MM
GS3:24.7MM
麻烦楼主帮我看看是男孩还是女孩，我现在36周了，很想知道宝宝性别。期待您的回复~！
你好,我老婆47天孕囊大小是9*14*21mm,54天孕囊大小15*16*18mm,11W+1天孕囊大小21*52*54mm,楼主,您看我家的宝宝是男孩还是女孩? 谢谢了!
还有人在这里啊? lz太监了!
我的孕囊只有两个数据,是4.9X3.0,孕8周照的
请楼主帮我看一下吧,胚芽是1.8的
你们的怎么都有三个数据呀,我的胚芽大小算不算呢
怀孕7周半B超检查所见：前位子宫，宫腔内见孕囊回声，大小约38*23*41mm，胎芽大小约19*8mm，原始心管搏动可见，卵黄囊可见。 ------------------------------------ 请楼主帮忙看看男女。。。。
44天BC所见：16*32*32
18*18*10
是男是女呀
怀孕10周妊娠囊为56*34*55是男还是女呢？
看在我手机爬楼的辛苦劲上，楼主帮我看看吧，我的7周的时候做的，27×34×11，是男宝还是女宝？谢谢楼主大好人
楼主你好，我40多天做的b超，孕囊大小是40*21*14mm请麻烦帮我看看是男孩还是女孩，谢谢了！
在哪里看回复呢？我这么看不到啊？？？
停经46天,孕囊大小是34mm*15mm*18mm,类圆形,是男孩还是女孩?
普利司够昂,
停经第49天，孕期7周，子宫前位70mm*52mm*66mm，宫腔内孕囊22mm*36mm*10mm，囊内见胚胎9mm，胎心心跳141，麻烦你帮我看看
马克 留着回家对照数据看看
50天，孕囊33*32*17mm。 麻烦，请帮我看看，谢谢！
45天 孕囊34*31*11 麻烦帮我看看 谢谢
您好我怀孕73天照的孕囊大小是（长46mm*宽30mm）头臀长35mm，麻烦您帮我看下是男还是女？谢谢！
您好我怀孕49天孕囊大小是30×24×16，麻烦帮我看下是男孩还是女孩？多谢！
怀孕47天拍的B超。妊娠囊16*11*14，请帮我看下
23 是男是女呢？
楼主人呢？
孕五周1.5*1*0.7，是男是女？
好像很容易看懂的嘛： 我爱我家177，31X41X20，女宝； xwangmm，28*33*40mm，女宝； 我要小天使，17*21*9，第47天，男宝； ynuyashai，孕44天的时候，23*16*20，女宝； 小妮子爱宝宝123，孕51天照的 ， 18*09*22 ，男宝； 千年菩提树 ，七周28*18*13，女宝； sjdyb，14*13*10，女宝； 一诺千金*22，女宝； 战争没有预演，54天孕囊大小15*16*18mm，女宝； 好孕Mami*41，男宝； 樂尐寳 ，44天BC所见：16*32*32，男宝； chounimade，18*18*10，女宝； 我爱兔宝宝啊，56*34*55，男宝。 霹雳焦猪，27*34*11，男宝； hzy家有宝贝，40*21*14，女宝； zying*18，女宝； 蒋至尊 ，22*36*10，男宝； 金毛可卡二宝，33*32*17，男宝； 陌上花开TINA，34*31*11，男宝； huiqinx ，30×24×16，女宝； 阿星的宝贝
，16*11*14，女宝； 无聊的人928
，48 27 23，女宝； 珺珺0418 ，1.5*1*0.7，女宝。
51天 43*24*23是男孩还是女孩呀
51天，41*23*13
45天，33x25x9
40多天左右
17*10*23mm
孕45天 42*30*35
是男孩还是女孩呀 谢谢
4月1号上月首次月经，5月17日B超孕囊13*12*8，5月26日再次B超显示运囊19*25*13，楼主帮忙看看是男孩还是女啊？希望是公主
孕40天不到 10*11*6 是男孩还是女孩呀 谢谢
孕52天，25*22*16 帮忙看看
孕8周左右：25*16*27，请帮我看下，谢谢！
48天b超结果：胎囊1.9*2.5*1.1cm
楼主，6w1d
22m*20m*9m帮帮忙，给我看看！
孕68天 ，胎囊 3.5*3.6*2.1，嘿嘿。
我的，2个月，孕囊大小约22*10*28mm
麻烦楼主帮看看哦。。。
末次月经11年4月12日，BC时间11年5月28日。 结果：宫内胎囊1.6*1.9*1.0 请楼主帮忙看下宝宝性别，超想知道！！！谢谢@@@@@@
30*21*14是男是女
孕42天 16*13*12 请问是男是女？
下周去照
医生只给了我两个数据。 42天时，19*8，能看吗。这样看是长形的，会不会把圆形截成长条形呢？
4.7CM*3.7CM*2.3CM帮我看下楼主
孕40+天。孕囊20*6*14mm
楼主帮我看下。。谢谢
LZ上面那个回复是第一次做B超的结果 今天又去医院做了检查。怀孕11周多了。B超结果显示孕囊62*38*56MM
能帮我看下吗。。。谢谢
楼主，62*38*58这哪个是长、宽、厚（高)啊 医院就只有这个数扰，不清楚哪个是长荣宽高。
@狮子传说-9 18:18:00 楼主，62*38*58这哪个是长、宽、厚（高)啊 医院就只有这个数扰，不清楚哪个是长荣宽高。 ----------------------怀孕70天，做BC。宫内可及42x29x54mm孕囊回声，囊内可及20x18mm胎芽，请问是男是女呀，-------
----------------------怀孕70天，做BC。宫内可及42x29x54mm孕囊回声，囊内可及20x18mm胎芽，请问是男是女呀，------- -----------------------------
40天。16X10X20mm是男宝还是女宝啊！谢谢楼主~
40天。16X10X20mm是男宝还是女宝啊！谢谢楼主~
50天。 24*34*19是男还是女啊！
51天。 24*33*13
是不是女宝呢？谢谢楼主
51天，29×26×21，应该是妹妹吧，楼主？
明儿个我去找数据麻烦楼主瞄下下哦！嘿嘿！
你好 我怀孕45天
孕囊大小是31*27*13，麻烦帮忙看下是男宝 还是女宝
你好 我怀孕45天
孕囊大小是31*27.13，麻烦帮忙看下是男宝还是女宝，谢谢！
您好，26*20*12，男宝还是女宝？谢谢
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请遵守言论规则，不得违反国家法律法规回复(Ctrl+Enter)Troubleshooting Power over Ethernet (PoE) - Cisco
Troubleshooting Power over Ethernet (PoE)
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Troubleshooting Power Over Ethernet
Revised August 23, 2010
This guide is for troubleshooting Power over Ethernet (PoE) in the Catalyst&3750-E, -E, and&3560 switch product families. Topics related to earlier PoE switches are also included.
For precise CLI and message format, see the switch software configuration guides and command references for the specific switches.
There are minor variations in both the command-line interface (CLI) and PoE functions from the earliest to the newest switch. Characteristics unique to a specific switch family or hardware version are listed when appropriate.
This guide contains these sections:
These terms used in this document:
o802.3af—The IEEE standard for PoE, often referred to as IEEE-compliant.
oCDP—Cisco Discovery Protocol. A Cisco Layer 2 protocol that enables switches and routers to quickly identify other Cisco devices when directly connected or connected to the same VLAN.
oCable diagnostics—A feature in specific switches that detects electrical defects in Ethernet cables. See also TDR.
oEndpoint PSE—Switched-based power source equipment, an Ethernet switch that provides PoE.
oFLP—Fast Link Pulse. An Ethernet protocol message used during standards-based link speed and duplex autonegotiation.
oFRU—field-replaceable unit, typically a power supply or fan module.
oMidspan PSE—power source equipment (a PoE source) in a patch panel.
oMPS—maintain power signature. The powered device must continue to be detected by a PSE in order to maintain a power feed from the PSE.
oPoE—Power over Ethernet
oPSE—power-source equipment. Typically an Ethernet switch or power patch panel that provides PoE.
oPTC—positive temperature coefficient (a self-resetting fuse)
oSNR—Signal-to-noise ratio
oTDR—time domain reflectometer. Also referred to as cable diagnostics, a feature used by switches to test electrical properties of Ethernet cables.
oUPS—Uninterruptible power supply
oWAP—wireless access point
Consider these guidelines before troubleshooting any PoE problem:
oCarefully verify the symptom. For example, does a powered device not power up at all, or does it power up briefly and then power down? Obtain as much detail as possible regarding the symptom, including any system messages from the PoE switch.
oDid the trouble occur on initial installation, or did it begin after the powered device was working normally?
oIf the trouble started after the powered device was working, what changed? Were there any hardware or software changes?
oDid any specific event occur at the powered device when the problem occurred?
oDid anything occur in the local network when the problem occurred? Use the show log privileged EXEC command to review the switch log and SNMP traps.
oDoes the problem happen at a specific time of day or night? (There could be electrical actions at the installation site possibly causing the problem.)
oIf an IP phone works normally between intermittent reboots, the problem could be related to PoE or an electrical connection in the cable. It could also be caused by a temporary loss of connectivity between the IP phone and the call manager.
Follow these steps when the trouble is on only one switch port. Confirm that PoE and Non-PoE devices do not work on this port but work on other ports.
Step&1 Verify that the powered device works on other ports and that the problem is only on one port.
Step&2 Use the show run and show interface status privileged EXEC commands to verify that the port is not shut down. (Most Cisco switches turn off port power when the port shuts down.)
Step&3 Use the show interface status privileged EXEC command to verify that the switch port is not error disabled.
Step&4 Use the show run and show power inline interface-id privileged EXEC command to verify that the power inline never interface configuration command is not configured on the port.
Step&5 Verify that the Ethernet cable from the phone to the switch port is good. Connect a known good non-PoE Ethernet device to the Ethernet cable, and make sure that it establishes a link and exchanges traffic with another host.
Step&6 Verify that the total cable length from the switch front panel to the connected device (powered device) is not more than 100 meters. For more information, see the cable diagnostics section in the switch software configuration guide.
Step&7 Disconnect the Ethernet cable from the switch port. Use a short Ethernet cable to connect a known good Ethernet device to this switch port (not at a patch panel). Verify that the device establishes an Ethernet link and exchanges traffic with another host, or ping the port VLAN SVI. Next, connect a powered device to this port, and verify that it powers on. If it does not power on, go to Step 8.
Step&8 Use the show inline power and show inline power detail privileged EXEC commands to compare the number of connected powered devices against the switch power budget (available PoE). Verify that switch power budget can power the device.
Note If the switch power budget is depleted, additional powered devices will not power-on when connected to a PoE port. CDP (Cisco Discovery Protocol) helps identify Cisco devices and correctly establish the switch power budget.
These sections provide additional information and include command examples about troubleshooting a switch that has no PoE on one port:
Follow these steps when there is no power on any port or a consecutive group of ports. Confirm that nonpowered Ethernet devices can establish an Ethernet link on any port and that PoE devices do not power on.
Step&1 Use the show interface status privileged EXEC command to verify that the ports are not shut down and not error disabled.
Step&2 Use the show env all, show interface status, and show power inline privileged EXEC commands to review power status if no powered device on any port can power on. Use the show log privileged EXEC command to review alarms reported earlier by system messages.
Step&3 If the trouble is on all ports, the PoE section of the power supply might be defective if the switch works normally except for PoE and if non-PoE devices can establish an Ethernet link on any port. If the trouble is on a consecutive group of ports but not all ports, there could be a defective PoE subsection in the switch.
Step&4 If there is a persistent alarm related to power, replace the power supply if it is field-replaceable. Otherwise, replace the switch.
Step&5 If there are no alarms reported by LEDs, CLI messages, or in the output of the show env all privileged EXEC command, connect a powered device directly to a switch port. Do not use the existing distribution cables. Use only a short patch cord to make the connection.
Step&6 Enter the shut and no shut interface configuration commands on this port. Use the show power inline privileged EXEC command to verify that the powered device receives power when the port is not shut down.
In some cases, it may be appropriate to disconnect the Ethernet cables from all but one switch port, and leave a powered device connected to only that PoE port.
If this connection using a short patch cord allows the powered device to power on, verify that all intermediate patch panels are correctly connected, and that the total cable length does not exceed 100 meters. If the cable diagnostics feature is supported by the switch, temporarily disconnect the powered device, and use this feature to verify total cable length.
Step&7 If a powered device powers on when it is the only one connected to the switch, enter the shut and no shut interface configuration commands on the remaining ports. Reconnect the Ethernet lines one at a time to the switch PoE ports. Use the show interface status and show power inline privileged EXEC commands as each line and powered device is reconnected to monitor inline power statistics and port status.
Follow these steps when a working Cisco IP Phone or wireless access point intermittently reloads or disconnects from inline power.
Step&1 Verify all electrical connections from the switch to the powered device. Any unreliable connection results in power interruptions and intermittent powered device operations, such as powered device disconnects and reloads.
Step&2 Verify that the total cable length from the switch front panel to the connected device (powered device) is not more than 100 meters. For more information, see the cable diagnostics section in the switch software configuration guide.
Step&3 Notice what might be changing in the electrical environment at the switch site. What is happening at the powered device when the disconnect occurs?
Step&4 Use the show log privileged EXEC command to review messages and events. Notice whether any other error messages are reported by the switch at the same time that a disconnect occurs.
Step&5 Verify that a Cisco IP Phone is not losing access to the call manager immediately before the reload occurs. (It might be a network problem, not a PoE problem.)
Step&6 Connect a non-PoE device to the port, and verify that it works. If a non-PoE device has link problems or a high error rate, the problem might be an unreliable cable connection between the switch port and the user.
Note If a powered device can power up when only one powered device is connected to the switch but not when all powered devices are connected, it is possible that the power budget was depleted. Connect powered devices one at a time, and enter the shut and no shut interface configuration commands as each device is connected. This clears any error-disabled states. Use the show interface status and show power inline privileged EXEC commands to monitor inline power statistics and port status as each device is connected.
These sections provide additional information and include command examples about troubleshooting a Cisco IP Phone that disconnects or resets:
Follow these steps when a non-Cisco powered device is connected to a Cisco PoE switch, but never powers up, or powers up and then quickly disconnects from power (powers down). Non-PoE devices work normally.
Step&1 Use the show power inline privileged EXEC command to verify that the switch power budget (available PoE) is not depleted before or after the powered device is connected. Verify that sufficient power is available for the powered device type.
Step&2 Use the show interface status privileged EXEC command to verify that the powered device is detected by the switch when connected.
Step&3 Use the show log privileged EXEC command to verify that the powered device is not causing an overcurrent condition on the port. Verify the symptom precisely: Does the phone initially power on and then disconnect? If so, the problem might be an initial current surge that exceeds a current-limit threshold for the switch port.
Step&4 Verify that the powered device is compatible with the Cisco switch. For example, if both units are standards-compliant, they should interoperate. CDP cannot be used to identify a non-Cisco device, and the switch must rely on accurate detection and classification when working with a non-Cisco device.
These links provide additional information and include command examples for troubleshooting a non-Cisco powered device that does not work on a Cisco PoE switch:
A switch uses detection to determine whether a powered device is connected to a port. PoE switches generally do not apply power to the Ethernet line unless a powered device is detected. When a powered device is connected to a PoE switch port, the switch uses one of these methods to detect the powered device:
oDC detection, sometimes called IEEE standard or 802.3af standard detection. Cisco IP phones support both DC and AC detection.
oCisco Detection, also called prestandard or AC detection. Prestandard Cisco IP phones use this method.
Cisco and non-Cisco PoE switches and powered devices are in two major categories:
oPre-IEEE standard (for example, Catalyst 3500)
oPost-IEEE standard (for example, Catalyst , 3560G, 3750G, 3560-E, and 3750-E)
Prestandard and poststandard phones might use different detection and connect or disconnect methods.
Note that powered device detection occurs when an Ethernet device is first connected to a PoE port. If a non-PoE device is connected to a PoE port, detection is deactivated. If the non-PoE device is later disconnected and replaced by a powered device, the switch might not detect it immediately. A timeout of several seconds must expire before detection is reenabled and active after a linkdown and linkup change.
This can also be called prestandard detection or discovery.
The Catalyst 3500 and earlier PoE switches use Cisco prestandard discovery to detect IP phones or other powered devices.
oThe switch sends a special Fast Link Pulse (FLP) signal to any device connected to the port.
oThe switch port determines if the special FLP signal is looped back by the powered device receive pair to the send pair. The only devices that loop back the FLP signal are those that would use inline power.
oWhen the switch detects the looped-back FLP signal and determines that it should provide inline power to the port, the switch determines if there is power available for the connected device. The switch might use a default power allocation to check available power. It can then adjust this allocation based on CDP information from a Cisco powered device.
oThe switch port then applies power to the connected device, and the relay inside the phone releases the loopback, as shown in .
oIf the powered device is a Cisco device, it boots, and CDP becomes active. The power budget in the switch can be adjusted by power requirement information in CDP messages from the powered device.
Figure&1 Powered Device
Standards-based Cisco PoE equipment conforms to the IEEE standards for five power classifications for powered devices.
When the switch detects a powered device and grants a power request, the switch can adjust the power budget (available power) according to the powered-device IEEE classification.
PoE classes describe a range of power used by a specific powered device. Some powered devices require more power than others, and power classes allowed switches to manage a power budget or available power. When a powered device is detected and its class is identified, the switch allocates (reserves) the appropriate power range.
The switch can determine the IEEE power class of the powered device by applying approximately 20 VDC to the line and measuring the resulting current flow. IEEE-compliant powered devices will produce a very specific current flow in response to the 20 VDC applied by the switch.
shows the IEEE standard power classes.
Table&1 IEEE Standard Power Classes
0-4 mA, 6 mA max.
9-12 mA, 14.5 mA max.
17-20 mA, 23 mA max.
26-30 mA, 33 mA max.
36-44 mA, 48 mA max.
Some of the power from the switch port is dissipated in the cable due to wire resistance, especially on cables as long as 100 meters. The remaining power is available to the powered device.
Most powered devices do not use the maximum power of their classes. For example, some IP phones are in the class 3 category, but consume less than 15.4 W.
If the powered device is Class 0 (class status unknown or prestandard) or Class 3, the switch must initially budget 15.4 W for the device, regardless of the actual amount of power needed by the powered device. If the powered device reports a higher class than its actual power consumption or does not support power classification (defaults to Class 0), the switch can power fewer devices if it uses the IEEE class information to establish and track the power budget. (Cisco switches and Cisco powered devices can also use CDP to establish the correct power usage for the powered device, but this occurs after the powered device is powered-up and fully operational.) Some switches can measure the actual power used on a per-port basis.
After classification, the switch applies 48 to 52 VDC to the line, which is the operational voltage of telephones and wireless access points. The powered device is now fully powered and should be operational (or registering with the call manager if the powered device is an IP phone).
Most earlier prestandard switches such as the Catalyst 3500 can not provide full power to newer devices such as IP phones with a color display. Bringing the phone up in reduced power mode at least allows it to operate, even though possibly with reduced features or reduced display brightness.
The switch uses maintain power signature (MPS) to detect the continued presence of a powered device after detection and after power is applied. As long as a power signature is present, the switch provides PoE. Cisco switches and Cisco IOS use various MPS versions as described in these sections:
The powered device must maintain its power signature to maintain a PoE feed from the switch. PoE is typically removed within 500 milliseconds after the switch no longer detects a power signature. All disconnect methods occur at the physical layer.
Catalyst&3750-E, -E, and 3560 switches support DC current MPS. The switch port removes power if the DC current in the current loop to the powered device is below a specific threshold for 300 to 400 milliseconds. When a powered-up device is disconnected, the current between the switch port receive and send pairs drops to 0.
As long as DC current is flowing between minimum and maximum thresholds, the switch determines that a powered device is connected, powered, and should continue receiving power, as shown in . An unreliable connection at some point between the switch and powered device can cause a false disconnect.
Figure&2 DC Current Flowing Between Switch and Powered Device
A device that is locally powered by an AC power module is detected by the PoE switch when connected to a port. However, the switch either provides or removes power based on a low current threshold (for example, the powered device is not using power from the switch.)
When powered devices are locally powered (no PoE), it might be appropriate in some cases to use the power inline never interface configuration command:
Switch(config)# int g0/1
Switch(config-if)# power inline never
Some early Catalyst 3750 and 3560 switches apply a 100-Hz signal between the receive and send pairs of the Ethernet port. A low-pass filter in the powered device loads (attenuates) the 100-Hz signal level below a specific threshold. The low-pass filter works only at 100 Hz and does not loop back normal traffic or Ethernet control signals.
The switch does not detect the attenuated 100-Hz signal when the powered device has the low-pass filter between the receive and send pairs. This means that a powered device is still connected and powered on, and that power to the device should continue, as shown in .
Figure&3 100-Hz Amplitude
When the powered device is disconnected, the100-Hz signal loading is removed from the line and the&100 Hz signal goes up beyond a specific threshold. The switch detects the signal level increase and recognizes that a powered device has been disconnected. The switch removes PoE from the Ethernet port.
Some early Catalyst 3560 and 3750 PoE switches use the 100-Hz MPS method with early Cisco IOS versions, but later Cisco IOS versions on these switches change the MPS mode to DC current.
If Cisco detection is used, a Cisco PoE switch generally removes PoE from a port if the switch port detects loss of Ethernet link. (If IEEE detection is used, DC or AC MPS methods detect disconnects. Power to a device can continue when an MPS signal is present, even if the Ethernet link is down.) The disconnect method depends on the connected powered device.
A Cisco switch reports when a powered device is connected or disconnected and when an Ethernet link state changes. This example shows a Cisco IP phone that was disconnected from the Ethernet port and then reconnected. The switch then detects a powered device, applies PoE, and detects MPS (Ethernet link).
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/3, changed state to
%ILPOWER-5-IEEE_DISCONNECT: Interface Gi1/0/3: PD removed
%LINK-3-UPDOWN: Interface GigabitEthernet1/0/3, changed state to down
%ILPOWER-7-DETECT: Interface Gi1/0/3: Power Device detected: IEEE PD
%ILPOWER-5-POWER_GRANTED: Interface Gi1/0/3: Power granted
%LINK-3-UPDOWN: Interface GigabitEthernet1/0/3, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/3, changed state to up
Note Unreliable plugs or jacks at any point between the phone and switch can cause the same disconnections.
CDP (Cisco Discovery Protocol) is a Cisco-proprietary Layer 2 protocol that runs on most Cisco equipment and shares information about directly connected Cisco equipment.
Cisco PoE switches using CDP can recognize Cisco powered devices such as IP phones and wireless access points. The actual power requirement can be advertised by the powered device, and the unused class power is returned to the switch power budget.
To use CDP for powered device discovery, enable it on the switch and on the PoE ports. (CDP is typically enabled by default.)
When a Cisco powered device (phone or WAP) powers on, CDP sends a message that tells the switch how much power the powered device actually needs. The switch CPU adjusts the power allocation for the port and adjusts the power budget.
Without CDP, if a powered device is connected but the class is 0 (default) or cannot be identified, the switch must reserve the maximum per-port PoE for the powered device. This can quickly deplete the power budget and, in a worst case, could result in a total artificial power budget depletion. Then the switch might not allocate power to a detected powered device even though power is still available.
For example, if a non-Cisco IEEE 802.3af Class 3 powered device is detected which requires only 9 W, but the actual requirement is not known by the PoE switch, the switch must initially budget the full per-port class power of 15.4 W even though the device will use only 9 W. This wastes 6.4 W, and this quickly adds as multiple similar devices are connected to the switch. An improper classification signature in the powered device can cause the same problem. This might prevent all intended devices from receiving power. Catalyst , and newer switches monitor the actual per-port power used after powered device detection is complete and PoE is applied.
A Cisco IEEE+CDP powered device such as the 7970G IP phone initially powers up in low-power mode (6.3 W), then sends a CDP message with the actual power requirements of the device. If the required power is less than the default 15.4 W for a Class-3 device, the switch updates its power budget. If the requested power exceeds the power budget available for the switch, power is either be denied, or the port remains in low-power mode (typically 7 W).
Use the show power inline privileged EXEC command to review these factors:
oPoE power available per switch
oPoE power used by all ports in the switch
oPoE power used by each connected powered device
oPoE power classification
To see connected Cisco devices, use the show cdp neighbor or show cdp neighbor detail privileged EXEC commands:
Stack-1# show cdp neighbor
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Local Intrface
Capability
Stack-1# show cdp neighbor detail
-------------------------
Device ID: SEP
Entry address(es): IP address: 192.168.1.249
Platform: Cisco IP Phone 7970,
Capabilities: Host Phone
Interface: GigabitEthernet1/0/2,
Port ID (outgoing port): Port 1
Holdtime : 150 sec
Note The maximum required power for this phone is 10250 milliwatts (10.25 W), but the phone can operate with reduced screen brightness at 6.3 W.
SCCP70.8-0-0-74S
advertisement version: 2
Duplex: full
Power drawn: 10.250 Watts
Power request id: 28024, Power management id: 3
Power request levels are: 0 0 0
This example shows the allocated and power budget for two switches in a Stackwise stack. Switch 1 (Module 1) is a 3750-E, and switch 2 is a 3750G.
Stack-1# show power inline
This example shows per-port power usage:
Interface Admin
--------- ------ ---------- ------- ------------------- ----- ----
IP Phone 7960
IP Phone 7970
IP Phone CP-7970G
AIR-AP1220-IOS
Note This 7970 is a Class-3 phone, but uses only 10.3 W (maximum) in this configuration. The&7970G is using&15.4 W due to maximum screen brightness.
In this example, some of the phones are early prestandard units. The indicator of standard or nonstandard varies depending the switch model and Cisco IOS version. Failing to identify a specific class is typically a sign of a prestandard powered device.
The show power inline command offers port-specific information containing elements of the show cdp neighbor detail and show inline power privileged EXEC commands:
3750# show power inline g2/0/14
Interface Admin
--------- ------ ---------- ------- ------------------- ----- ----
IP Phone CP-7970G
AdminPowerMax
AdminConsumption
---------- --------------- ------------------
It is possible that some of the prestandard non-Cisco powered devices might not be detected by a Cisco switch, but later IEEE-compliant powered devices should not have this problem when connected to a IEEE-compliant Cisco switch.
CDP identifies Cisco powered devices and establishes the appropriate power budget, but non-Cisco devices do not have the advantage of CDP. If a non-Cisco powered device can be detected but the power class cannot be identified, the switch must default to class 0 and allocate the maximum power for the port. This can cause a premature depletion of the power budget.
For example, unidentified devices might need only 6 W, but they are allocated maximum PoE power (up to 15.4 W), and the power budget can be depleted before all available ports on the switch have been provided power. This results in a symptom where a known-good powered device is connected to a known-good PoE port on a switch, but the powered device does not power on.
Some of the newer switches, such as the Catalyst 3750-E and 3560-E can adjust the power budget according to actual measured power usage.
Some non-Cisco devices might have an excessive surge in current when first connected to a PoE port. The switch initially provides power to the port, then quickly removes power due to a momentary, overcurrent condition. The powered device appears to power on, but then quickly powers down.
This error message from a Catalyst 3750 is possibly caused by an overcurrent condition:
%ILPOWER-5-ILPOWER_POWER_DENY: Interface Gi1/0/1: inline power denied
This error message from a Catalyst 6000 is possibly caused by an overcurrent condition:
%C6K_POWER-SP-1-PD_HW_FAULTY: The device connected to port 3/21 has a hardware problem.
Power is turned off on the port.
Any current over 450 mA is usually considered an overcurrent condition.
All PoE switches have electronic voltage and current regulators that detect an overcurrent threshold and disconnect DC power from the line to prevent damage.
Cisco PoE switches have two levels of overcurrent protection:
oElectronic regulation (per port)
oFuses (per switch)
This prevents excessive current from being delivered by the PoE port, which could possibly result in damage to port-level components.
Earlier PoE switches such as the Catalyst 3524PWR support a nominal 6 or 7 W per port. If the line current on a particular port increases to approximately 9 W, the switch removes power to prevent circuit damage due to overheating.
Newer switches such as the Catalyst 3750-E, 3560-E, and 3750G support up to 15.4 W per port. Some earlier switches might not be able to provide 15.4 W on all ports, and the maximum power delivered to all ports is limited by a power budget. The power budget is usually related to the switch power-supply capability and the amount of delivered power. All newer switches can power a mix of 7.5 W and 15.4 W powered devices until the power budget is depleted.
The Catalyst 3750-E and 3560-E switches support 15.4 W per port up to 48 ports depending on the FRU power supply installed. Switches that provide 15.4 W per port typically remove power from the port if power dissipation reaches approximately 17 W.
Normally the automatic electronic current regulation is completely effective, and fuse action is very seldom necessary or observed. Fuses can either be self-resetting (replacement not required) or a basic, fast-acting fuse that requires replacement after burning open. Fuses are included in the PoE power supply as a safeguard, but the port-level electronic regulators are the primary method of overcurrent protection.
The self-resetting fuses are PTC (positive temperature coefficient) resistors. These components are a polymer-based temperature-dependent resistor, not actually a fuse. When activated by heat, PTC units increase in resistance.
PTC fuses are also sensitive to high ambient temperature (inside the Ethernet switch chassis), so these devices might appear to activate more quickly when exposed to higher temperatures. The actual current threshold is a factor of both heat from circuit current and heat from ambient temperature inside the chassis. The advantage of a self-resetting fuse is, if activated, power is restored to the line when the overcurrent condition is corrected. The disadvantage of these devices is after the first time they are activated, they usually exhibit a slightly higher resistance thereafter, even when the device temperature returns to normal or ambient.
The standard, fast-acting fuses used in some switch power supplies open if a circuit in the switch fails and causes excessive current. This is unusual, but if it occurs, replace the power supply (if it is replaceable) or replace the switch.
In normal operation, the electronic regulators limit the per-port PoE current to safe levels. The fuses are a second level of safety. If an overcurrent condition occurs on one port, it does not affect other ports.
Some Cisco switches allow manual adjustments to the power budget and per-port control of the maximum PoE power delivered to a powered device.
In this example, the power inline consumption interface configuration command adjusts the switch power budget to&7&W when the actual power required by a powered device is known but cannot be determined by IEEE classification. This prevents artificial depletion of the switch power budget:
3750E(config-if)# power inline consumption 7000
3750E# show power inline consumption
A powered device might use more power than set by the power inline consumption command, so you must carefully make adjustments to the power budget. An accurate power budget protects the switch from an overcurrent condition.
In this example, the power budget is manually adjusted to 4 W on a specific port. When a Class 3 phone was connected, it required more power than 4 W:
Switch(config-if)# power inline consumption 4000
%ILPOWER-4-LOG_OVERDRAWN: Interface Gi1/0/1 is overdrawing power. it is consuming 4794
milliwatts where as maximum configured power is 4000 milliwatts.
In this case, there was remaining available power at system level, so power was delivered to the powered device. The syslog message was an alert to report the powered device exceeding the configured power budget for the port. However, the powered device did not exceed the maximum power delivery capability of the switch.
When the power budget has been manually adjusted at port-level, the show power inline privileged EXEC command shows the administratively assigned power, not the actual power used by the powered device:
Switch# show power inline
Interface Admin
--------- ------ ---------- ------- ------------------- ----- ----
IP Phone 7970
To see the power used by the powered device, use this command:
Switch# show cdp neighbors g5/0/1 detail
-------------------------
Device ID: SEP
Platform: Cisco IP Phone 7970,
Capabilities: Host Phone
Interface: GigabitEthernet5/0/1,
Power drawn: 6.300 Watts
Power request levels are: 0 0 0
The power request levels for this powered device (a Cisco 7970 phone) are 10.25 W and 6.3 W. The phone can operate at 6.3 W with reduced screen brightness. Full screen brightness requires&10.25 W. The phone in the example is operating at 6.3 W.
The Catalyst&3750-E, -E, and 3560 series PoE switches allow maximum power delivery to a powered device on a per-port basis. This allows an override of the powered device classification. In this example, the inline power static interface configuration command sets an absolute limit of 5 W on a specific port. The powered device requires more power than is allowed by the 5 W limit, and inline power is denied:
Switch(config-if)# inline power static max 5000
%ILPOWER-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
%ILPOWER-5-ILPOWER_POWER_DENY: Interface Gi5/0/1: inline power denied
An under-powered condition can result in a permanent loopback from a Cisco-powered device, which also error disables the port. This is usually the result of an inappropriate option error when entering the inline power static max interface configuration command. (Set a more appropriate power limit and then enter the shut and no shut interface configuration commands on the port to clear an error-disabled state and to restore the port to service.)
Enter the show interface status privileged EXEC command to review the operational state of the port:
Switch# show interface status
Speed Type
err-disabled 7
auto 10/100/1000BaseTX
In this example, port G5/0/1 was set to a static limit of 5 W, less than the minimum power required by the powered device. Power was denied by the switch port. The admin PoE status of port G5/0/1 is static, and the maximum allowed power is 5 W:
Switch# show power inline
Interface Admin
--------- ------ ---------- ------- ------------------- ----- ----
static off
IP Phone CP-7970G
Class 3 powered devices are allocated 15.4 W by default. After power is applied and a Cisco-powered device boots up, CDP is enabled, and the power budget can be adjusted from CDP. Some non-Cisco class-3 phones (no CDP) use considerably less than 15.4 W maximum, although 15.4 W is budgeted if a switch can not measure the actual power consumption. For example, an Avaya 2620SW uses approximately 8 W maximum. If power consumption (allocated power) is limited to 8 or 9 W, more phones can be powered because the switch power budget is not quickly and artificially depleted. Some powered devices can operate at reduced power, but this usually limits the features or capability of the powered device. For example, a Cisco 7970 phone can operate with reduced screen brightness, using less power than the maximum advertised power requirement.
In newer switches, per-port power can be increased from 15.4 W to 20 W for special-purpose powered devices. Multiple ports can provide this increased power at the same time, but the switch power budget is more quickly depleted.
Switch(config-if)# power inline port maximum 20000
Some switches have a PoE LED in the system status group of LEDs. This LED indicates the per-port and system PoE status, as shown in .
Table&2 Port LEDs
PoE display mode is not selected by the mode button. When this LED is off, none of the 10/100/1000 ports have been denied power, and none are in a fault condition.
PoE mode is selected by the mode button, and the PoE status is shown on the port LEDs. A green port LED means that the port is supplying PoE.
Blinking amber
PoE mode is not selected by the mode button. At least one of the 10/100/1000 ports has been denied power, or at least one of the 10/100/1000 ports has a PoE fault.
A stable Ethernet link can sometimes be established on Category-5 cable lengths up to 130 meters, especially for 10Base-T, but the standard maximum Category 5 or Category 6 cable length for all&10/100/1000Base-T Ethernet types is 100 meters.
Category 5 and Category 6 defines the high-frequency transmission characteristics of cable over distance, which is important for 100Base-T and Gigabit Ethernet. However, PoE relies mainly on the total DC resistance of a specific length of cable, and much less on the high-frequency transmission characteristics of the cable.
PoE is delivered as a current loop through the powered device, with current flowing on both wires of the send pair and both wires of the receive pair. Both wires of each pair are required to reduce DC circuit losses and prevent excessive voltage and current drop on cables up to 100 meters long. Using both wires of each pair is the same as using a larger wire size for DC current delivery to the powered device.
An unreliable connection in a jack or at a patch panel can disrupt both Ethernet and PoE. In this case, insufficient current might be delivered to the powered device on longer cables, as shown in .
Figure&4 Open Connection
PoE requires both conductors of the send and receive pairs in order to deliver PoE power at 100 meters cable length, as shown in . On shorter cables with one wire of the send or receive pair open, it might be possible to have powered device detection and classification, but no Ethernet link. On longer cables with an open wire in one of the pairs, it might not be possible to detect or power-up a powered device.
The 100-meter limit for twisted-pair Ethernet cable assumes:
oNot more than four RJ-45 connection points in the transmission path
o90 meters of solid-strand Category 5 or 5e
o10 meters of flexible multistrand cable (2-to-5 meters of multistrand Category 5 patch cords)
Figure&5 Cable Limitations
If multistrand wire (flexible patch cord) is used for the entire cable length, it might not be possible to establish a stable Ethernet link on more than 60 to 70 meters of cable (depending on the transmission line characteristics). The multistrand cable can deliver adequate power to almost any powered device at 100 meters, but multi-strand cable does not have optimum transmission characteristics for Ethernet at 100 meters. Each RJ-45 connector in the signal path introduces a small amount of signal loss and might also become an unreliable DC connection point.
Sometimes Ethernet performance and PoE performance problems are related, but Ethernet links can often be established on cables too long for effective PoE delivery. For example, some transceiver pairs can establish an Ethernet link on 120 meters of good quality Category 5 or Category 6 cable, but a powered device that requires 15 Watts may not power up on 120 meters of cable. Maximum functional Ethernet cable length usually depends on the capability of the connected transceivers. Maximum delivery length of PoE usually depends on the powered-device power requirements.
These factors significantly affect Ethernet reliability and performance:
oCable type, typically Category 5, 5e, 6
oThe amount of single-strand and multistrand wire in the signal path.
oThe number of connectors in the signal path and the reliability of all mechanical connections.
oAny shorts or opens in the signal path
oAmount of electrical noise induced into the Ethernet cable and the resulting degradation to SNR.
These factors significantly affect PoE reliability:
oThe total end-to-end DC resistance between the switch port and powered device.
oThe reliability of all mechanical connections (connectors)
oAny intermittent shorts or opens in the signal path.
oFor AC detection and AC disconnect, the amount of electrical noise in the Ethernet cable
The cable diagnostics (or TDR) feature, in most of the newer Ethernet switches can be valuable when measuring cable length to an open or shorted cable pair. Cable length is usually measured to an open (nothing connected at the powered device end of the cable). Refer to the switch software configuration guide to determine cable diagnostics TDR availability and related commands.
Several debug functions are available for PoE troubleshooting. You can monitor debug functions for all PoE states and events.
To see powered device detection and PoE states on a specific port, use debug ilpower port privileged EXEC command:
Switch# debug ilpower port
%ILPOWER-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
%ILPOWER-5-POWER_GRANTED: Interface Gi5/0/1: Power granted
%LINK-3-UPDOWN: Interface GigabitEthernet5/0/1, changed state to up
This debug ilpower powerman (inline power management) example shows information about power requests from a powered device that has been granted inline (PoE) power:
Switch# debug ilpower powerman
%ILPOWER-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
Ilpower interface (Gi5/0/1) power status change, allocated power 15400
%ILPOWER-5-POWER_GRANTED: Interface Gi5/0/1: Power granted
%LINK-3-UPDOWN: Interface GigabitEthernet5/0/1, changed state to up
power_consumption = 6300
power_request_level[] =
Interface (Gi5/0/1) select power 10250
req id 28024, man id 2, pwr avail 15400, pwr man 10250
Note that 15.4 W was initially allocated before classification was complete and CDP messages were processed. This powered device (a Cisco 7970 phone) has an actual power requirement of 10.25 W for screen full brightness, but can operate with reduced screen brightness on less than 10 W.
If the port is administratively shut down while PoE is applied and powerman debug is active, these messages (or equivalent) appear:
ilpower delete power from pd linkdown Gi5/0/1
Ilpower interface (Gi5/0/1), delete allocated power 10250
The power is no longer allocated and is returned to the switch power budget.
This debug example shows the sequence and result of powered device detection:
Switch# debug ilpower event
%ILPOWER-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
ILP uses AC Disconnect(Gi5/0/1): state=ILP_IEEE_PD_DETECTED_S, event= IEEE_PWR_GOOD_EV
%ILPOWER-5-POWER_GRANTED: Interface Gi5/0/1: Power granted
ILP uses AC Disconnect(Gi5/0/1): state=ILP_LINK_UP_S, event=PHY_LINK_UP_EV
%LINK-3-UPDOWN: Interface GigabitEthernet5/0/1, changed state to up
In this example, inline power is denied because the powered device is requesting more power than is available in the switch power budget:
3w4d: %ILPOWR-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
3w4d: %ILPOWER-5-ILPOWER_POWER_DENY: Interface Gi5/0/1: inline power denied
Several additional PoE debug commands are available for monitoring specific events or functions related to detection, classification, and power grants.
Various disturbances on the AC power line (mains) can cause unusual PoE problems. The power supplies in various switches and powered devices sometimes have unique reactions to AC input disturbances. Problems caused by AC disruptions are usually temporary or one-time occurrences. For example, a specific switch or powered device might reboot due to an AC power problem, while other switches or powered devices might exhibit a greater immunity to the problem.
This is a typical occurrence during lightning storms or AC power maintenance. In a worst-case situation, a PoE power supply might appear to shut down (no PoE output voltage to any port). It is possible the Ethernet functions in the switch appear normal, and only the PoE functions are disrupted or degraded, or the switch might power-down completely in response to the AC disturbance. Powered devices might exhibit unusual behavior.
In such cases, power cycle the switch (unplug the switch, wait at least 3 seconds, then plug it back in). This ensures a total system reset and should restore normal operation.
When several or all PoE ports in a switch cannot provide power to powered devices, and entering the shut and no shut interface configuration commands does not clear the problem, verify that a power cycle restores the switch to normal operation. If it does, suspect an AC power disturbance as the source of the problem.
Sometimes an AC power disturbance can be so brief that it is missed by site personnel but detected by the switch or other electronic systems. If this happens frequently on multiple switches, carefully determine the stability and reliability of AC power. If it often occurs on only one switch, and other switches in the same location do not exhibit the symptom, contact Cisco TAC for guidance.
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为什么内存只有十二G，店员明明说有十六G
我有更好的答案
手机的话是正常的，系统要占用一部分存储的。可以说手机全是这样的。如果是电脑的运行内存，这样就不对了。可以直接卖电脑的问清楚是什么情况。
采纳率：86%
来自团队：
4GB内存条被店家扣留了。
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&&太平洋游戏网 DOTA2 为什么有的说准，有的说不准，其实是自己不会看数据而已，或者数据时间不合适，应该这样看，首先数据不能超过8周，40多天是最合适的，然后就是要有3个数据的，没有3个数据的，一律不能判断，孕囊都是圆柱状的，每个B超师做B超的时候，截面会截取的方位不一样，有的横截面，有的截取竖截面，所以，看图片是长的还是圆的，不能判断男女。
打个比方，比如40*20mm的孕囊，这样根本没有办法判断，表面上看两个数据相差一倍，应该是男孩，错了，因为没有第三个数据，如果是40*40*20，那肯定是男孩，但是如果B超师横截面时，孕囊就成了40*40mm的两个数据，看上去就是圆的了，然后造成了，孕囊是圆的，结果怎么生出了儿子，貌似不准的误导。所以数据一定要有3个。
如果孕囊成等差数列，比如40*30*20，这样就是女孩，但是如果B超师取了40*20的截面，貌似男孩的数据，结果生出了闺女，造成孕囊看男女不准的说法。
亲们自己回家看吧，记住2个数据的话，看不了，因为每个B超师获取孕囊的方位不一样，所以不能判断，有3个数据的，是最好判断的，两个数据差不多，第三个数据比前两个小一倍，那肯定是儿子，如果成递减数据就是女儿。
还有一种情况就是第三个数据小很多的，比如40*38*10，像10比40和38小很多很多，这个也可能是女儿，但80％还是儿子。
有的数据最大数值不是在最前面，不要紧，把3个数据从大到小排好，自己看吧，比如：40*25*39，或者39*25*40，等等，这样都是儿子。 如果有看不懂的，把数据发上来，我来帮你看， 再次声明一下，两个数据的不要发了，看不来的。基本每天早上会回复你们。大家也可以把肚子照片发过来共同识别，准确率相对较高，但需要30周以后的。
楼主发言：1次 发图：0张 | 更多
31X41X20 LZ说的我没看懂~~还是你帮我看看吧~~
lz,你好. 孕7周时B超单,宫腔内可见28*33*40mm妊娠囊 请问,是男孩还是女孩? 谢谢
17*21*9，第47天，谢谢LZ
孕44天的时候 23*16*20麻烦LZ也帮我看看啊，谢谢了
孕51天照的 宫腔内见一胎囊大小 18*09*22 孕57天照的 宫腔内见一胎囊大小 31*17*26
楼主怎么没来了啊 大家都在等着呢 快点回来吧 帮我看看啊
七周28*18*13楼主也给我看看
45天做额BC
按照楼主额介绍 应该是女宝宝 如果真是女宝宝 就太开心了
楼主的这个方法应该还是挺准的，之前在网上介绍的方法都是两个数据的，而我自己的数据是三个的，所以一直不知道该怎么看。 我40天的孕囊：27*24*12，结果生的是小男孩。
你好,我老婆的11周1天的B超单上孕囊大小是21*52*54mm,楼主帮你忙分析下,是男孩女孩?谢谢
我5W+的数据为 18*12*22 帮我看一下是男是女了，谢了
请楼主帮我看一下吧，我是45天做的bc，符合7w+1。bc单上的数据是GS1:30.7MM GS2:17.6MM
GS3:24.7MM
麻烦楼主帮我看看是男孩还是女孩，我现在36周了，很想知道宝宝性别。期待您的回复~！
你好,我老婆47天孕囊大小是9*14*21mm,54天孕囊大小15*16*18mm,11W+1天孕囊大小21*52*54mm,楼主,您看我家的宝宝是男孩还是女孩? 谢谢了!
还有人在这里啊? lz太监了!
我的孕囊只有两个数据,是4.9X3.0,孕8周照的
请楼主帮我看一下吧,胚芽是1.8的
你们的怎么都有三个数据呀,我的胚芽大小算不算呢
怀孕7周半B超检查所见：前位子宫，宫腔内见孕囊回声，大小约38*23*41mm，胎芽大小约19*8mm，原始心管搏动可见，卵黄囊可见。 ------------------------------------ 请楼主帮忙看看男女。。。。
44天BC所见：16*32*32
18*18*10
是男是女呀
怀孕10周妊娠囊为56*34*55是男还是女呢？
看在我手机爬楼的辛苦劲上，楼主帮我看看吧，我的7周的时候做的，27×34×11，是男宝还是女宝？谢谢楼主大好人
楼主你好，我40多天做的b超，孕囊大小是40*21*14mm请麻烦帮我看看是男孩还是女孩，谢谢了！
在哪里看回复呢？我这么看不到啊？？？
停经46天,孕囊大小是34mm*15mm*18mm,类圆形,是男孩还是女孩?
普利司够昂,
停经第49天，孕期7周，子宫前位70mm*52mm*66mm，宫腔内孕囊22mm*36mm*10mm，囊内见胚胎9mm，胎心心跳141，麻烦你帮我看看
马克 留着回家对照数据看看
50天，孕囊33*32*17mm。 麻烦，请帮我看看，谢谢！
45天 孕囊34*31*11 麻烦帮我看看 谢谢
您好我怀孕73天照的孕囊大小是（长46mm*宽30mm）头臀长35mm，麻烦您帮我看下是男还是女？谢谢！
您好我怀孕49天孕囊大小是30×24×16，麻烦帮我看下是男孩还是女孩？多谢！
怀孕47天拍的B超。妊娠囊16*11*14，请帮我看下
23 是男是女呢？
楼主人呢？
孕五周1.5*1*0.7，是男是女？
好像很容易看懂的嘛： 我爱我家177，31X41X20，女宝； xwangmm，28*33*40mm，女宝； 我要小天使，17*21*9，第47天，男宝； ynuyashai，孕44天的时候，23*16*20，女宝； 小妮子爱宝宝123，孕51天照的 ， 18*09*22 ，男宝； 千年菩提树 ，七周28*18*13，女宝； sjdyb，14*13*10，女宝； 一诺千金*22，女宝； 战争没有预演，54天孕囊大小15*16*18mm，女宝； 好孕Mami*41，男宝； 樂尐寳 ，44天BC所见：16*32*32，男宝； chounimade，18*18*10，女宝； 我爱兔宝宝啊，56*34*55，男宝。 霹雳焦猪，27*34*11，男宝； hzy家有宝贝，40*21*14，女宝； zying*18，女宝； 蒋至尊 ，22*36*10，男宝； 金毛可卡二宝，33*32*17，男宝； 陌上花开TINA，34*31*11，男宝； huiqinx ，30×24×16，女宝； 阿星的宝贝
，16*11*14，女宝； 无聊的人928
，48 27 23，女宝； 珺珺0418 ，1.5*1*0.7，女宝。
51天 43*24*23是男孩还是女孩呀
51天，41*23*13
45天，33x25x9
40多天左右
17*10*23mm
孕45天 42*30*35
是男孩还是女孩呀 谢谢
4月1号上月首次月经，5月17日B超孕囊13*12*8，5月26日再次B超显示运囊19*25*13，楼主帮忙看看是男孩还是女啊？希望是公主
孕40天不到 10*11*6 是男孩还是女孩呀 谢谢
孕52天，25*22*16 帮忙看看
孕8周左右：25*16*27，请帮我看下，谢谢！
48天b超结果：胎囊1.9*2.5*1.1cm
楼主，6w1d
22m*20m*9m帮帮忙，给我看看！
孕68天 ，胎囊 3.5*3.6*2.1，嘿嘿。
我的，2个月，孕囊大小约22*10*28mm
麻烦楼主帮看看哦。。。
末次月经11年4月12日，BC时间11年5月28日。 结果：宫内胎囊1.6*1.9*1.0 请楼主帮忙看下宝宝性别，超想知道！！！谢谢@@@@@@
30*21*14是男是女
孕42天 16*13*12 请问是男是女？
下周去照
医生只给了我两个数据。 42天时，19*8，能看吗。这样看是长形的，会不会把圆形截成长条形呢？
4.7CM*3.7CM*2.3CM帮我看下楼主
孕40+天。孕囊20*6*14mm
楼主帮我看下。。谢谢
LZ上面那个回复是第一次做B超的结果 今天又去医院做了检查。怀孕11周多了。B超结果显示孕囊62*38*56MM
能帮我看下吗。。。谢谢
楼主，62*38*58这哪个是长、宽、厚（高)啊 医院就只有这个数扰，不清楚哪个是长荣宽高。
@狮子传说-9 18:18:00 楼主，62*38*58这哪个是长、宽、厚（高)啊 医院就只有这个数扰，不清楚哪个是长荣宽高。 ----------------------怀孕70天，做BC。宫内可及42x29x54mm孕囊回声，囊内可及20x18mm胎芽，请问是男是女呀，-------
----------------------怀孕70天，做BC。宫内可及42x29x54mm孕囊回声，囊内可及20x18mm胎芽，请问是男是女呀，------- -----------------------------
40天。16X10X20mm是男宝还是女宝啊！谢谢楼主~
40天。16X10X20mm是男宝还是女宝啊！谢谢楼主~
50天。 24*34*19是男还是女啊！
51天。 24*33*13
是不是女宝呢？谢谢楼主
51天，29×26×21，应该是妹妹吧，楼主？
明儿个我去找数据麻烦楼主瞄下下哦！嘿嘿！
你好 我怀孕45天
孕囊大小是31*27*13，麻烦帮忙看下是男宝 还是女宝
你好 我怀孕45天
孕囊大小是31*27.13，麻烦帮忙看下是男宝还是女宝，谢谢！
您好，26*20*12，男宝还是女宝？谢谢
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Troubleshooting Power over Ethernet (PoE)
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Troubleshooting Power Over Ethernet
Revised August 23, 2010
This guide is for troubleshooting Power over Ethernet (PoE) in the Catalyst&3750-E, -E, and&3560 switch product families. Topics related to earlier PoE switches are also included.
For precise CLI and message format, see the switch software configuration guides and command references for the specific switches.
There are minor variations in both the command-line interface (CLI) and PoE functions from the earliest to the newest switch. Characteristics unique to a specific switch family or hardware version are listed when appropriate.
This guide contains these sections:
These terms used in this document:
o802.3af—The IEEE standard for PoE, often referred to as IEEE-compliant.
oCDP—Cisco Discovery Protocol. A Cisco Layer 2 protocol that enables switches and routers to quickly identify other Cisco devices when directly connected or connected to the same VLAN.
oCable diagnostics—A feature in specific switches that detects electrical defects in Ethernet cables. See also TDR.
oEndpoint PSE—Switched-based power source equipment, an Ethernet switch that provides PoE.
oFLP—Fast Link Pulse. An Ethernet protocol message used during standards-based link speed and duplex autonegotiation.
oFRU—field-replaceable unit, typically a power supply or fan module.
oMidspan PSE—power source equipment (a PoE source) in a patch panel.
oMPS—maintain power signature. The powered device must continue to be detected by a PSE in order to maintain a power feed from the PSE.
oPoE—Power over Ethernet
oPSE—power-source equipment. Typically an Ethernet switch or power patch panel that provides PoE.
oPTC—positive temperature coefficient (a self-resetting fuse)
oSNR—Signal-to-noise ratio
oTDR—time domain reflectometer. Also referred to as cable diagnostics, a feature used by switches to test electrical properties of Ethernet cables.
oUPS—Uninterruptible power supply
oWAP—wireless access point
Consider these guidelines before troubleshooting any PoE problem:
oCarefully verify the symptom. For example, does a powered device not power up at all, or does it power up briefly and then power down? Obtain as much detail as possible regarding the symptom, including any system messages from the PoE switch.
oDid the trouble occur on initial installation, or did it begin after the powered device was working normally?
oIf the trouble started after the powered device was working, what changed? Were there any hardware or software changes?
oDid any specific event occur at the powered device when the problem occurred?
oDid anything occur in the local network when the problem occurred? Use the show log privileged EXEC command to review the switch log and SNMP traps.
oDoes the problem happen at a specific time of day or night? (There could be electrical actions at the installation site possibly causing the problem.)
oIf an IP phone works normally between intermittent reboots, the problem could be related to PoE or an electrical connection in the cable. It could also be caused by a temporary loss of connectivity between the IP phone and the call manager.
Follow these steps when the trouble is on only one switch port. Confirm that PoE and Non-PoE devices do not work on this port but work on other ports.
Step&1 Verify that the powered device works on other ports and that the problem is only on one port.
Step&2 Use the show run and show interface status privileged EXEC commands to verify that the port is not shut down. (Most Cisco switches turn off port power when the port shuts down.)
Step&3 Use the show interface status privileged EXEC command to verify that the switch port is not error disabled.
Step&4 Use the show run and show power inline interface-id privileged EXEC command to verify that the power inline never interface configuration command is not configured on the port.
Step&5 Verify that the Ethernet cable from the phone to the switch port is good. Connect a known good non-PoE Ethernet device to the Ethernet cable, and make sure that it establishes a link and exchanges traffic with another host.
Step&6 Verify that the total cable length from the switch front panel to the connected device (powered device) is not more than 100 meters. For more information, see the cable diagnostics section in the switch software configuration guide.
Step&7 Disconnect the Ethernet cable from the switch port. Use a short Ethernet cable to connect a known good Ethernet device to this switch port (not at a patch panel). Verify that the device establishes an Ethernet link and exchanges traffic with another host, or ping the port VLAN SVI. Next, connect a powered device to this port, and verify that it powers on. If it does not power on, go to Step 8.
Step&8 Use the show inline power and show inline power detail privileged EXEC commands to compare the number of connected powered devices against the switch power budget (available PoE). Verify that switch power budget can power the device.
Note If the switch power budget is depleted, additional powered devices will not power-on when connected to a PoE port. CDP (Cisco Discovery Protocol) helps identify Cisco devices and correctly establish the switch power budget.
These sections provide additional information and include command examples about troubleshooting a switch that has no PoE on one port:
Follow these steps when there is no power on any port or a consecutive group of ports. Confirm that nonpowered Ethernet devices can establish an Ethernet link on any port and that PoE devices do not power on.
Step&1 Use the show interface status privileged EXEC command to verify that the ports are not shut down and not error disabled.
Step&2 Use the show env all, show interface status, and show power inline privileged EXEC commands to review power status if no powered device on any port can power on. Use the show log privileged EXEC command to review alarms reported earlier by system messages.
Step&3 If the trouble is on all ports, the PoE section of the power supply might be defective if the switch works normally except for PoE and if non-PoE devices can establish an Ethernet link on any port. If the trouble is on a consecutive group of ports but not all ports, there could be a defective PoE subsection in the switch.
Step&4 If there is a persistent alarm related to power, replace the power supply if it is field-replaceable. Otherwise, replace the switch.
Step&5 If there are no alarms reported by LEDs, CLI messages, or in the output of the show env all privileged EXEC command, connect a powered device directly to a switch port. Do not use the existing distribution cables. Use only a short patch cord to make the connection.
Step&6 Enter the shut and no shut interface configuration commands on this port. Use the show power inline privileged EXEC command to verify that the powered device receives power when the port is not shut down.
In some cases, it may be appropriate to disconnect the Ethernet cables from all but one switch port, and leave a powered device connected to only that PoE port.
If this connection using a short patch cord allows the powered device to power on, verify that all intermediate patch panels are correctly connected, and that the total cable length does not exceed 100 meters. If the cable diagnostics feature is supported by the switch, temporarily disconnect the powered device, and use this feature to verify total cable length.
Step&7 If a powered device powers on when it is the only one connected to the switch, enter the shut and no shut interface configuration commands on the remaining ports. Reconnect the Ethernet lines one at a time to the switch PoE ports. Use the show interface status and show power inline privileged EXEC commands as each line and powered device is reconnected to monitor inline power statistics and port status.
Follow these steps when a working Cisco IP Phone or wireless access point intermittently reloads or disconnects from inline power.
Step&1 Verify all electrical connections from the switch to the powered device. Any unreliable connection results in power interruptions and intermittent powered device operations, such as powered device disconnects and reloads.
Step&2 Verify that the total cable length from the switch front panel to the connected device (powered device) is not more than 100 meters. For more information, see the cable diagnostics section in the switch software configuration guide.
Step&3 Notice what might be changing in the electrical environment at the switch site. What is happening at the powered device when the disconnect occurs?
Step&4 Use the show log privileged EXEC command to review messages and events. Notice whether any other error messages are reported by the switch at the same time that a disconnect occurs.
Step&5 Verify that a Cisco IP Phone is not losing access to the call manager immediately before the reload occurs. (It might be a network problem, not a PoE problem.)
Step&6 Connect a non-PoE device to the port, and verify that it works. If a non-PoE device has link problems or a high error rate, the problem might be an unreliable cable connection between the switch port and the user.
Note If a powered device can power up when only one powered device is connected to the switch but not when all powered devices are connected, it is possible that the power budget was depleted. Connect powered devices one at a time, and enter the shut and no shut interface configuration commands as each device is connected. This clears any error-disabled states. Use the show interface status and show power inline privileged EXEC commands to monitor inline power statistics and port status as each device is connected.
These sections provide additional information and include command examples about troubleshooting a Cisco IP Phone that disconnects or resets:
Follow these steps when a non-Cisco powered device is connected to a Cisco PoE switch, but never powers up, or powers up and then quickly disconnects from power (powers down). Non-PoE devices work normally.
Step&1 Use the show power inline privileged EXEC command to verify that the switch power budget (available PoE) is not depleted before or after the powered device is connected. Verify that sufficient power is available for the powered device type.
Step&2 Use the show interface status privileged EXEC command to verify that the powered device is detected by the switch when connected.
Step&3 Use the show log privileged EXEC command to verify that the powered device is not causing an overcurrent condition on the port. Verify the symptom precisely: Does the phone initially power on and then disconnect? If so, the problem might be an initial current surge that exceeds a current-limit threshold for the switch port.
Step&4 Verify that the powered device is compatible with the Cisco switch. For example, if both units are standards-compliant, they should interoperate. CDP cannot be used to identify a non-Cisco device, and the switch must rely on accurate detection and classification when working with a non-Cisco device.
These links provide additional information and include command examples for troubleshooting a non-Cisco powered device that does not work on a Cisco PoE switch:
A switch uses detection to determine whether a powered device is connected to a port. PoE switches generally do not apply power to the Ethernet line unless a powered device is detected. When a powered device is connected to a PoE switch port, the switch uses one of these methods to detect the powered device:
oDC detection, sometimes called IEEE standard or 802.3af standard detection. Cisco IP phones support both DC and AC detection.
oCisco Detection, also called prestandard or AC detection. Prestandard Cisco IP phones use this method.
Cisco and non-Cisco PoE switches and powered devices are in two major categories:
oPre-IEEE standard (for example, Catalyst 3500)
oPost-IEEE standard (for example, Catalyst , 3560G, 3750G, 3560-E, and 3750-E)
Prestandard and poststandard phones might use different detection and connect or disconnect methods.
Note that powered device detection occurs when an Ethernet device is first connected to a PoE port. If a non-PoE device is connected to a PoE port, detection is deactivated. If the non-PoE device is later disconnected and replaced by a powered device, the switch might not detect it immediately. A timeout of several seconds must expire before detection is reenabled and active after a linkdown and linkup change.
This can also be called prestandard detection or discovery.
The Catalyst 3500 and earlier PoE switches use Cisco prestandard discovery to detect IP phones or other powered devices.
oThe switch sends a special Fast Link Pulse (FLP) signal to any device connected to the port.
oThe switch port determines if the special FLP signal is looped back by the powered device receive pair to the send pair. The only devices that loop back the FLP signal are those that would use inline power.
oWhen the switch detects the looped-back FLP signal and determines that it should provide inline power to the port, the switch determines if there is power available for the connected device. The switch might use a default power allocation to check available power. It can then adjust this allocation based on CDP information from a Cisco powered device.
oThe switch port then applies power to the connected device, and the relay inside the phone releases the loopback, as shown in .
oIf the powered device is a Cisco device, it boots, and CDP becomes active. The power budget in the switch can be adjusted by power requirement information in CDP messages from the powered device.
Figure&1 Powered Device
Standards-based Cisco PoE equipment conforms to the IEEE standards for five power classifications for powered devices.
When the switch detects a powered device and grants a power request, the switch can adjust the power budget (available power) according to the powered-device IEEE classification.
PoE classes describe a range of power used by a specific powered device. Some powered devices require more power than others, and power classes allowed switches to manage a power budget or available power. When a powered device is detected and its class is identified, the switch allocates (reserves) the appropriate power range.
The switch can determine the IEEE power class of the powered device by applying approximately 20 VDC to the line and measuring the resulting current flow. IEEE-compliant powered devices will produce a very specific current flow in response to the 20 VDC applied by the switch.
shows the IEEE standard power classes.
Table&1 IEEE Standard Power Classes
0-4 mA, 6 mA max.
9-12 mA, 14.5 mA max.
17-20 mA, 23 mA max.
26-30 mA, 33 mA max.
36-44 mA, 48 mA max.
Some of the power from the switch port is dissipated in the cable due to wire resistance, especially on cables as long as 100 meters. The remaining power is available to the powered device.
Most powered devices do not use the maximum power of their classes. For example, some IP phones are in the class 3 category, but consume less than 15.4 W.
If the powered device is Class 0 (class status unknown or prestandard) or Class 3, the switch must initially budget 15.4 W for the device, regardless of the actual amount of power needed by the powered device. If the powered device reports a higher class than its actual power consumption or does not support power classification (defaults to Class 0), the switch can power fewer devices if it uses the IEEE class information to establish and track the power budget. (Cisco switches and Cisco powered devices can also use CDP to establish the correct power usage for the powered device, but this occurs after the powered device is powered-up and fully operational.) Some switches can measure the actual power used on a per-port basis.
After classification, the switch applies 48 to 52 VDC to the line, which is the operational voltage of telephones and wireless access points. The powered device is now fully powered and should be operational (or registering with the call manager if the powered device is an IP phone).
Most earlier prestandard switches such as the Catalyst 3500 can not provide full power to newer devices such as IP phones with a color display. Bringing the phone up in reduced power mode at least allows it to operate, even though possibly with reduced features or reduced display brightness.
The switch uses maintain power signature (MPS) to detect the continued presence of a powered device after detection and after power is applied. As long as a power signature is present, the switch provides PoE. Cisco switches and Cisco IOS use various MPS versions as described in these sections:
The powered device must maintain its power signature to maintain a PoE feed from the switch. PoE is typically removed within 500 milliseconds after the switch no longer detects a power signature. All disconnect methods occur at the physical layer.
Catalyst&3750-E, -E, and 3560 switches support DC current MPS. The switch port removes power if the DC current in the current loop to the powered device is below a specific threshold for 300 to 400 milliseconds. When a powered-up device is disconnected, the current between the switch port receive and send pairs drops to 0.
As long as DC current is flowing between minimum and maximum thresholds, the switch determines that a powered device is connected, powered, and should continue receiving power, as shown in . An unreliable connection at some point between the switch and powered device can cause a false disconnect.
Figure&2 DC Current Flowing Between Switch and Powered Device
A device that is locally powered by an AC power module is detected by the PoE switch when connected to a port. However, the switch either provides or removes power based on a low current threshold (for example, the powered device is not using power from the switch.)
When powered devices are locally powered (no PoE), it might be appropriate in some cases to use the power inline never interface configuration command:
Switch(config)# int g0/1
Switch(config-if)# power inline never
Some early Catalyst 3750 and 3560 switches apply a 100-Hz signal between the receive and send pairs of the Ethernet port. A low-pass filter in the powered device loads (attenuates) the 100-Hz signal level below a specific threshold. The low-pass filter works only at 100 Hz and does not loop back normal traffic or Ethernet control signals.
The switch does not detect the attenuated 100-Hz signal when the powered device has the low-pass filter between the receive and send pairs. This means that a powered device is still connected and powered on, and that power to the device should continue, as shown in .
Figure&3 100-Hz Amplitude
When the powered device is disconnected, the100-Hz signal loading is removed from the line and the&100 Hz signal goes up beyond a specific threshold. The switch detects the signal level increase and recognizes that a powered device has been disconnected. The switch removes PoE from the Ethernet port.
Some early Catalyst 3560 and 3750 PoE switches use the 100-Hz MPS method with early Cisco IOS versions, but later Cisco IOS versions on these switches change the MPS mode to DC current.
If Cisco detection is used, a Cisco PoE switch generally removes PoE from a port if the switch port detects loss of Ethernet link. (If IEEE detection is used, DC or AC MPS methods detect disconnects. Power to a device can continue when an MPS signal is present, even if the Ethernet link is down.) The disconnect method depends on the connected powered device.
A Cisco switch reports when a powered device is connected or disconnected and when an Ethernet link state changes. This example shows a Cisco IP phone that was disconnected from the Ethernet port and then reconnected. The switch then detects a powered device, applies PoE, and detects MPS (Ethernet link).
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/3, changed state to
%ILPOWER-5-IEEE_DISCONNECT: Interface Gi1/0/3: PD removed
%LINK-3-UPDOWN: Interface GigabitEthernet1/0/3, changed state to down
%ILPOWER-7-DETECT: Interface Gi1/0/3: Power Device detected: IEEE PD
%ILPOWER-5-POWER_GRANTED: Interface Gi1/0/3: Power granted
%LINK-3-UPDOWN: Interface GigabitEthernet1/0/3, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/3, changed state to up
Note Unreliable plugs or jacks at any point between the phone and switch can cause the same disconnections.
CDP (Cisco Discovery Protocol) is a Cisco-proprietary Layer 2 protocol that runs on most Cisco equipment and shares information about directly connected Cisco equipment.
Cisco PoE switches using CDP can recognize Cisco powered devices such as IP phones and wireless access points. The actual power requirement can be advertised by the powered device, and the unused class power is returned to the switch power budget.
To use CDP for powered device discovery, enable it on the switch and on the PoE ports. (CDP is typically enabled by default.)
When a Cisco powered device (phone or WAP) powers on, CDP sends a message that tells the switch how much power the powered device actually needs. The switch CPU adjusts the power allocation for the port and adjusts the power budget.
Without CDP, if a powered device is connected but the class is 0 (default) or cannot be identified, the switch must reserve the maximum per-port PoE for the powered device. This can quickly deplete the power budget and, in a worst case, could result in a total artificial power budget depletion. Then the switch might not allocate power to a detected powered device even though power is still available.
For example, if a non-Cisco IEEE 802.3af Class 3 powered device is detected which requires only 9 W, but the actual requirement is not known by the PoE switch, the switch must initially budget the full per-port class power of 15.4 W even though the device will use only 9 W. This wastes 6.4 W, and this quickly adds as multiple similar devices are connected to the switch. An improper classification signature in the powered device can cause the same problem. This might prevent all intended devices from receiving power. Catalyst , and newer switches monitor the actual per-port power used after powered device detection is complete and PoE is applied.
A Cisco IEEE+CDP powered device such as the 7970G IP phone initially powers up in low-power mode (6.3 W), then sends a CDP message with the actual power requirements of the device. If the required power is less than the default 15.4 W for a Class-3 device, the switch updates its power budget. If the requested power exceeds the power budget available for the switch, power is either be denied, or the port remains in low-power mode (typically 7 W).
Use the show power inline privileged EXEC command to review these factors:
oPoE power available per switch
oPoE power used by all ports in the switch
oPoE power used by each connected powered device
oPoE power classification
To see connected Cisco devices, use the show cdp neighbor or show cdp neighbor detail privileged EXEC commands:
Stack-1# show cdp neighbor
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Local Intrface
Capability
Stack-1# show cdp neighbor detail
-------------------------
Device ID: SEP
Entry address(es): IP address: 192.168.1.249
Platform: Cisco IP Phone 7970,
Capabilities: Host Phone
Interface: GigabitEthernet1/0/2,
Port ID (outgoing port): Port 1
Holdtime : 150 sec
Note The maximum required power for this phone is 10250 milliwatts (10.25 W), but the phone can operate with reduced screen brightness at 6.3 W.
SCCP70.8-0-0-74S
advertisement version: 2
Duplex: full
Power drawn: 10.250 Watts
Power request id: 28024, Power management id: 3
Power request levels are: 0 0 0
This example shows the allocated and power budget for two switches in a Stackwise stack. Switch 1 (Module 1) is a 3750-E, and switch 2 is a 3750G.
Stack-1# show power inline
This example shows per-port power usage:
Interface Admin
--------- ------ ---------- ------- ------------------- ----- ----
IP Phone 7960
IP Phone 7970
IP Phone CP-7970G
AIR-AP1220-IOS
Note This 7970 is a Class-3 phone, but uses only 10.3 W (maximum) in this configuration. The&7970G is using&15.4 W due to maximum screen brightness.
In this example, some of the phones are early prestandard units. The indicator of standard or nonstandard varies depending the switch model and Cisco IOS version. Failing to identify a specific class is typically a sign of a prestandard powered device.
The show power inline command offers port-specific information containing elements of the show cdp neighbor detail and show inline power privileged EXEC commands:
3750# show power inline g2/0/14
Interface Admin
--------- ------ ---------- ------- ------------------- ----- ----
IP Phone CP-7970G
AdminPowerMax
AdminConsumption
---------- --------------- ------------------
It is possible that some of the prestandard non-Cisco powered devices might not be detected by a Cisco switch, but later IEEE-compliant powered devices should not have this problem when connected to a IEEE-compliant Cisco switch.
CDP identifies Cisco powered devices and establishes the appropriate power budget, but non-Cisco devices do not have the advantage of CDP. If a non-Cisco powered device can be detected but the power class cannot be identified, the switch must default to class 0 and allocate the maximum power for the port. This can cause a premature depletion of the power budget.
For example, unidentified devices might need only 6 W, but they are allocated maximum PoE power (up to 15.4 W), and the power budget can be depleted before all available ports on the switch have been provided power. This results in a symptom where a known-good powered device is connected to a known-good PoE port on a switch, but the powered device does not power on.
Some of the newer switches, such as the Catalyst 3750-E and 3560-E can adjust the power budget according to actual measured power usage.
Some non-Cisco devices might have an excessive surge in current when first connected to a PoE port. The switch initially provides power to the port, then quickly removes power due to a momentary, overcurrent condition. The powered device appears to power on, but then quickly powers down.
This error message from a Catalyst 3750 is possibly caused by an overcurrent condition:
%ILPOWER-5-ILPOWER_POWER_DENY: Interface Gi1/0/1: inline power denied
This error message from a Catalyst 6000 is possibly caused by an overcurrent condition:
%C6K_POWER-SP-1-PD_HW_FAULTY: The device connected to port 3/21 has a hardware problem.
Power is turned off on the port.
Any current over 450 mA is usually considered an overcurrent condition.
All PoE switches have electronic voltage and current regulators that detect an overcurrent threshold and disconnect DC power from the line to prevent damage.
Cisco PoE switches have two levels of overcurrent protection:
oElectronic regulation (per port)
oFuses (per switch)
This prevents excessive current from being delivered by the PoE port, which could possibly result in damage to port-level components.
Earlier PoE switches such as the Catalyst 3524PWR support a nominal 6 or 7 W per port. If the line current on a particular port increases to approximately 9 W, the switch removes power to prevent circuit damage due to overheating.
Newer switches such as the Catalyst 3750-E, 3560-E, and 3750G support up to 15.4 W per port. Some earlier switches might not be able to provide 15.4 W on all ports, and the maximum power delivered to all ports is limited by a power budget. The power budget is usually related to the switch power-supply capability and the amount of delivered power. All newer switches can power a mix of 7.5 W and 15.4 W powered devices until the power budget is depleted.
The Catalyst 3750-E and 3560-E switches support 15.4 W per port up to 48 ports depending on the FRU power supply installed. Switches that provide 15.4 W per port typically remove power from the port if power dissipation reaches approximately 17 W.
Normally the automatic electronic current regulation is completely effective, and fuse action is very seldom necessary or observed. Fuses can either be self-resetting (replacement not required) or a basic, fast-acting fuse that requires replacement after burning open. Fuses are included in the PoE power supply as a safeguard, but the port-level electronic regulators are the primary method of overcurrent protection.
The self-resetting fuses are PTC (positive temperature coefficient) resistors. These components are a polymer-based temperature-dependent resistor, not actually a fuse. When activated by heat, PTC units increase in resistance.
PTC fuses are also sensitive to high ambient temperature (inside the Ethernet switch chassis), so these devices might appear to activate more quickly when exposed to higher temperatures. The actual current threshold is a factor of both heat from circuit current and heat from ambient temperature inside the chassis. The advantage of a self-resetting fuse is, if activated, power is restored to the line when the overcurrent condition is corrected. The disadvantage of these devices is after the first time they are activated, they usually exhibit a slightly higher resistance thereafter, even when the device temperature returns to normal or ambient.
The standard, fast-acting fuses used in some switch power supplies open if a circuit in the switch fails and causes excessive current. This is unusual, but if it occurs, replace the power supply (if it is replaceable) or replace the switch.
In normal operation, the electronic regulators limit the per-port PoE current to safe levels. The fuses are a second level of safety. If an overcurrent condition occurs on one port, it does not affect other ports.
Some Cisco switches allow manual adjustments to the power budget and per-port control of the maximum PoE power delivered to a powered device.
In this example, the power inline consumption interface configuration command adjusts the switch power budget to&7&W when the actual power required by a powered device is known but cannot be determined by IEEE classification. This prevents artificial depletion of the switch power budget:
3750E(config-if)# power inline consumption 7000
3750E# show power inline consumption
A powered device might use more power than set by the power inline consumption command, so you must carefully make adjustments to the power budget. An accurate power budget protects the switch from an overcurrent condition.
In this example, the power budget is manually adjusted to 4 W on a specific port. When a Class 3 phone was connected, it required more power than 4 W:
Switch(config-if)# power inline consumption 4000
%ILPOWER-4-LOG_OVERDRAWN: Interface Gi1/0/1 is overdrawing power. it is consuming 4794
milliwatts where as maximum configured power is 4000 milliwatts.
In this case, there was remaining available power at system level, so power was delivered to the powered device. The syslog message was an alert to report the powered device exceeding the configured power budget for the port. However, the powered device did not exceed the maximum power delivery capability of the switch.
When the power budget has been manually adjusted at port-level, the show power inline privileged EXEC command shows the administratively assigned power, not the actual power used by the powered device:
Switch# show power inline
Interface Admin
--------- ------ ---------- ------- ------------------- ----- ----
IP Phone 7970
To see the power used by the powered device, use this command:
Switch# show cdp neighbors g5/0/1 detail
-------------------------
Device ID: SEP
Platform: Cisco IP Phone 7970,
Capabilities: Host Phone
Interface: GigabitEthernet5/0/1,
Power drawn: 6.300 Watts
Power request levels are: 0 0 0
The power request levels for this powered device (a Cisco 7970 phone) are 10.25 W and 6.3 W. The phone can operate at 6.3 W with reduced screen brightness. Full screen brightness requires&10.25 W. The phone in the example is operating at 6.3 W.
The Catalyst&3750-E, -E, and 3560 series PoE switches allow maximum power delivery to a powered device on a per-port basis. This allows an override of the powered device classification. In this example, the inline power static interface configuration command sets an absolute limit of 5 W on a specific port. The powered device requires more power than is allowed by the 5 W limit, and inline power is denied:
Switch(config-if)# inline power static max 5000
%ILPOWER-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
%ILPOWER-5-ILPOWER_POWER_DENY: Interface Gi5/0/1: inline power denied
An under-powered condition can result in a permanent loopback from a Cisco-powered device, which also error disables the port. This is usually the result of an inappropriate option error when entering the inline power static max interface configuration command. (Set a more appropriate power limit and then enter the shut and no shut interface configuration commands on the port to clear an error-disabled state and to restore the port to service.)
Enter the show interface status privileged EXEC command to review the operational state of the port:
Switch# show interface status
Speed Type
err-disabled 7
auto 10/100/1000BaseTX
In this example, port G5/0/1 was set to a static limit of 5 W, less than the minimum power required by the powered device. Power was denied by the switch port. The admin PoE status of port G5/0/1 is static, and the maximum allowed power is 5 W:
Switch# show power inline
Interface Admin
--------- ------ ---------- ------- ------------------- ----- ----
static off
IP Phone CP-7970G
Class 3 powered devices are allocated 15.4 W by default. After power is applied and a Cisco-powered device boots up, CDP is enabled, and the power budget can be adjusted from CDP. Some non-Cisco class-3 phones (no CDP) use considerably less than 15.4 W maximum, although 15.4 W is budgeted if a switch can not measure the actual power consumption. For example, an Avaya 2620SW uses approximately 8 W maximum. If power consumption (allocated power) is limited to 8 or 9 W, more phones can be powered because the switch power budget is not quickly and artificially depleted. Some powered devices can operate at reduced power, but this usually limits the features or capability of the powered device. For example, a Cisco 7970 phone can operate with reduced screen brightness, using less power than the maximum advertised power requirement.
In newer switches, per-port power can be increased from 15.4 W to 20 W for special-purpose powered devices. Multiple ports can provide this increased power at the same time, but the switch power budget is more quickly depleted.
Switch(config-if)# power inline port maximum 20000
Some switches have a PoE LED in the system status group of LEDs. This LED indicates the per-port and system PoE status, as shown in .
Table&2 Port LEDs
PoE display mode is not selected by the mode button. When this LED is off, none of the 10/100/1000 ports have been denied power, and none are in a fault condition.
PoE mode is selected by the mode button, and the PoE status is shown on the port LEDs. A green port LED means that the port is supplying PoE.
Blinking amber
PoE mode is not selected by the mode button. At least one of the 10/100/1000 ports has been denied power, or at least one of the 10/100/1000 ports has a PoE fault.
A stable Ethernet link can sometimes be established on Category-5 cable lengths up to 130 meters, especially for 10Base-T, but the standard maximum Category 5 or Category 6 cable length for all&10/100/1000Base-T Ethernet types is 100 meters.
Category 5 and Category 6 defines the high-frequency transmission characteristics of cable over distance, which is important for 100Base-T and Gigabit Ethernet. However, PoE relies mainly on the total DC resistance of a specific length of cable, and much less on the high-frequency transmission characteristics of the cable.
PoE is delivered as a current loop through the powered device, with current flowing on both wires of the send pair and both wires of the receive pair. Both wires of each pair are required to reduce DC circuit losses and prevent excessive voltage and current drop on cables up to 100 meters long. Using both wires of each pair is the same as using a larger wire size for DC current delivery to the powered device.
An unreliable connection in a jack or at a patch panel can disrupt both Ethernet and PoE. In this case, insufficient current might be delivered to the powered device on longer cables, as shown in .
Figure&4 Open Connection
PoE requires both conductors of the send and receive pairs in order to deliver PoE power at 100 meters cable length, as shown in . On shorter cables with one wire of the send or receive pair open, it might be possible to have powered device detection and classification, but no Ethernet link. On longer cables with an open wire in one of the pairs, it might not be possible to detect or power-up a powered device.
The 100-meter limit for twisted-pair Ethernet cable assumes:
oNot more than four RJ-45 connection points in the transmission path
o90 meters of solid-strand Category 5 or 5e
o10 meters of flexible multistrand cable (2-to-5 meters of multistrand Category 5 patch cords)
Figure&5 Cable Limitations
If multistrand wire (flexible patch cord) is used for the entire cable length, it might not be possible to establish a stable Ethernet link on more than 60 to 70 meters of cable (depending on the transmission line characteristics). The multistrand cable can deliver adequate power to almost any powered device at 100 meters, but multi-strand cable does not have optimum transmission characteristics for Ethernet at 100 meters. Each RJ-45 connector in the signal path introduces a small amount of signal loss and might also become an unreliable DC connection point.
Sometimes Ethernet performance and PoE performance problems are related, but Ethernet links can often be established on cables too long for effective PoE delivery. For example, some transceiver pairs can establish an Ethernet link on 120 meters of good quality Category 5 or Category 6 cable, but a powered device that requires 15 Watts may not power up on 120 meters of cable. Maximum functional Ethernet cable length usually depends on the capability of the connected transceivers. Maximum delivery length of PoE usually depends on the powered-device power requirements.
These factors significantly affect Ethernet reliability and performance:
oCable type, typically Category 5, 5e, 6
oThe amount of single-strand and multistrand wire in the signal path.
oThe number of connectors in the signal path and the reliability of all mechanical connections.
oAny shorts or opens in the signal path
oAmount of electrical noise induced into the Ethernet cable and the resulting degradation to SNR.
These factors significantly affect PoE reliability:
oThe total end-to-end DC resistance between the switch port and powered device.
oThe reliability of all mechanical connections (connectors)
oAny intermittent shorts or opens in the signal path.
oFor AC detection and AC disconnect, the amount of electrical noise in the Ethernet cable
The cable diagnostics (or TDR) feature, in most of the newer Ethernet switches can be valuable when measuring cable length to an open or shorted cable pair. Cable length is usually measured to an open (nothing connected at the powered device end of the cable). Refer to the switch software configuration guide to determine cable diagnostics TDR availability and related commands.
Several debug functions are available for PoE troubleshooting. You can monitor debug functions for all PoE states and events.
To see powered device detection and PoE states on a specific port, use debug ilpower port privileged EXEC command:
Switch# debug ilpower port
%ILPOWER-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
%ILPOWER-5-POWER_GRANTED: Interface Gi5/0/1: Power granted
%LINK-3-UPDOWN: Interface GigabitEthernet5/0/1, changed state to up
This debug ilpower powerman (inline power management) example shows information about power requests from a powered device that has been granted inline (PoE) power:
Switch# debug ilpower powerman
%ILPOWER-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
Ilpower interface (Gi5/0/1) power status change, allocated power 15400
%ILPOWER-5-POWER_GRANTED: Interface Gi5/0/1: Power granted
%LINK-3-UPDOWN: Interface GigabitEthernet5/0/1, changed state to up
power_consumption = 6300
power_request_level[] =
Interface (Gi5/0/1) select power 10250
req id 28024, man id 2, pwr avail 15400, pwr man 10250
Note that 15.4 W was initially allocated before classification was complete and CDP messages were processed. This powered device (a Cisco 7970 phone) has an actual power requirement of 10.25 W for screen full brightness, but can operate with reduced screen brightness on less than 10 W.
If the port is administratively shut down while PoE is applied and powerman debug is active, these messages (or equivalent) appear:
ilpower delete power from pd linkdown Gi5/0/1
Ilpower interface (Gi5/0/1), delete allocated power 10250
The power is no longer allocated and is returned to the switch power budget.
This debug example shows the sequence and result of powered device detection:
Switch# debug ilpower event
%ILPOWER-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
ILP uses AC Disconnect(Gi5/0/1): state=ILP_IEEE_PD_DETECTED_S, event= IEEE_PWR_GOOD_EV
%ILPOWER-5-POWER_GRANTED: Interface Gi5/0/1: Power granted
ILP uses AC Disconnect(Gi5/0/1): state=ILP_LINK_UP_S, event=PHY_LINK_UP_EV
%LINK-3-UPDOWN: Interface GigabitEthernet5/0/1, changed state to up
In this example, inline power is denied because the powered device is requesting more power than is available in the switch power budget:
3w4d: %ILPOWR-7-DETECT: Interface Gi5/0/1: Power Device detected: IEEE PD
3w4d: %ILPOWER-5-ILPOWER_POWER_DENY: Interface Gi5/0/1: inline power denied
Several additional PoE debug commands are available for monitoring specific events or functions related to detection, classification, and power grants.
Various disturbances on the AC power line (mains) can cause unusual PoE problems. The power supplies in various switches and powered devices sometimes have unique reactions to AC input disturbances. Problems caused by AC disruptions are usually temporary or one-time occurrences. For example, a specific switch or powered device might reboot due to an AC power problem, while other switches or powered devices might exhibit a greater immunity to the problem.
This is a typical occurrence during lightning storms or AC power maintenance. In a worst-case situation, a PoE power supply might appear to shut down (no PoE output voltage to any port). It is possible the Ethernet functions in the switch appear normal, and only the PoE functions are disrupted or degraded, or the switch might power-down completely in response to the AC disturbance. Powered devices might exhibit unusual behavior.
In such cases, power cycle the switch (unplug the switch, wait at least 3 seconds, then plug it back in). This ensures a total system reset and should restore normal operation.
When several or all PoE ports in a switch cannot provide power to powered devices, and entering the shut and no shut interface configuration commands does not clear the problem, verify that a power cycle restores the switch to normal operation. If it does, suspect an AC power disturbance as the source of the problem.
Sometimes an AC power disturbance can be so brief that it is missed by site personnel but detected by the switch or other electronic systems. If this happens frequently on multiple switches, carefully determine the stability and reliability of AC power. If it often occurs on only one switch, and other switches in the same location do not exhibit the symptom, contact Cisco TAC for guidance.
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