IP Phone auto-negotiation issues

Unanswered Question
Apr 6th, 2009

We are currently evaluating a Cisco IP Phone, model 7961G-GE. A nice feature of this device is that it lets you run both a PC and the phone through the same ethernet line. However, we are running into issues with the phone not negotiating speeds properly on the line. Both the SW and PC ports are set to auto-negotiate in the phone settings, however only the PC port negotiates correctly. All of our networking equipment supports gigabit connections, and the PC port negotiates to gigabit speed, but the SW port always negotiates to 100 megabit speed. If I forceably set both the PC and SW ports to gigabit speed, the phone drops the connection and cannot seem to communicate any more. I have tested this on a POE switch as well as on a non-POE switch (with the phone running on external power) and noticed the same behavior both times. Any ideas on how we can get this working properly are much appreciated.

Thanks in advance,


I have this problem too.
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CHRIS CHARLEBOIS Mon, 04/06/2009 - 12:59

Can you specify the switch that you are connecting the phone to and provide the configuration of the ports on that switch? It sounds like the issue is with the switch port configuartion.

chrismedc Mon, 04/06/2009 - 13:06

Appreciate the quick response. The switch is a Cisco Catalyst 3750-E, and all 48 ports are enabled and set to "Auto" for Speed, Duplex and PoE.

I guess I could forceably set the speed to 1000 on the port that I have the phone connected to, but my guess would be that it will lose connection -- similarly to when I changed the connection speed on the phone itself.

Jonathan Schulenberg Sun, 04/12/2009 - 18:09

Have you tried updating the phone's firmware? This sounds like a bug although I didn't see any public bugs in the toolkit on this. If newer firmware doesn't solve it, it's time for TAC.


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