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New Member

VOIP power inline

I trying to use a voip with a phone Alcatel voip.

I've the follow problem.

When i connect the rj45 in the phone the switch don't power the phone.


WS-C6509 Software, Version NmpSW: 7.6(8)

System Bootstrap Version: 7.1(1)

System Boot Image File is 'bootflash:cat6000-sup2k8.7-6-8.bin'

Hardware Version: 3.0 Model: WS-C6509

PS1 Module: WS-CAC-1300W

PS2 Module: WS-CAC-1300W

Thanks for your help



Re: VOIP power inline

Hi FCostalunga,

Switch does not provide the inline power to the phone it is the line card with inline power module which provides the power over ethernet.

Can you please paste the output of sh mod and confirm which module and port you are installing your ip phone and I will confirm if that line card is capable of providing the inline power or not.

For an exmple if you have line card WS-X6148A-GE-TX on you cat6k and you connect your ip phone to this you will not get any inline power but if your line card is WS-X6148A-GE-45AF it will provide the inline power if you connect your ip phone. So it all depends on the line card which you are using to connect you ip phones.

Use this link

and serach for inline and you will find the moduels which are capable of providing inline power.

HTH, if yes please rate the post


New Member

Re: VOIP power inline

i use the module 10/100 WS-X6348-RJ-45

Mod Slot Ports Module-Type Model Sub Status

1000BaseX Supervisor WS-X6K-SUP2 2GE yes ok

Multilayer Switch Feature WS-F6K-MSFC2 no ok

1000BaseX Supervisor WS-X6K-SUP2-2GE yes standby

Multilayer Switch Feature WS-F6K-MSFC2 no standby

1000BaseX Ethernet WS-X6408A-GBIC no ok

1000BaseX Ethernet WS-X6408A-GBIC no ok

10/100BaseTX Ethernet WS-X6348-RJ-45 yes ok

10/100BaseTX Ethernet WS-X6348-RJ-45 yes ok

MF_DT_C1AB_1> show port capabilities 5/4

Model WS-X6348-RJ-45

Port 5/4

Type 10/100BaseTX

Speed auto,10,100

Duplex half,full

Trunk encap type 802.1Q,ISL

Trunk mode on,off,desirable,auto,nonegotiate

Channel yes

Broadcast suppression percentage(0-100)

Flow control receive-(off,on),send-(off)

Security yes

Dot1x yes

Membership static,dynamic

Fast start yes

QOS scheduling rx-(1q4t),tx-(2q2t)

CoS rewrite yes

ToS rewrite DSCP

UDLD yes

Inline power auto,off

AuxiliaryVlan 1..1000,1025..4094,untagged,dot1p,none

SPAN source,destination

COPS port group 5/1-48

Link debounce timer yes

Dot1q-all-tagged yes

Jumbo frames yes

Port ASIC group

Re: VOIP power inline

You may suffer a physical issue, I had the same with a Cisco Access Point and 3rd party InLine power.

The solution was a simple balun that changes polarity to match the other equipment. You may have the same issue connecting a Cisco switch to a non-Cisco 802.3af device. I found a reference from Cisco that depicts what I mean:

Look at figure1; the intended balun is described as a prestandard passive splitter. I hope that this guess will be useful for you.



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