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Community Member

Catalyst 2960 Problem with Cisco SPA512

Hi there,


I hope someone can help me.


I don't have much experience with switches, I'm doing the desktop support in our company.

We have Catalyst 4510 R+E to 2 Catalyst 2960 switches and seperate VLAN's for IP Phones and for Internet in one part of our office.


Now I'm running into trouble with some IP Phones that are connected to the 2960 switches. It appears only to happen with Cisco's SPA-512. I've tried FW 7.5.2, 7.5.5 and 7.5.5b. These phones sporadically drop the call / connection, with the red MIC button blinking. Based on my research this means that it looses Internet connection. I have 1 SPA512 with FW 7.5.1 that does not show these symptoms.


I have other phones SPA942 and Polycom IP335 in the same area behind the same switches and no issues.

We've tried to disable auto negotiate and set a fixed transmition rate or either 1Gbps and 100Mbps, both without success.


I also have SPA512 in other areas of the office just connected to our Catalyst 4510 R+E and they work just fine. That's why I don't believe it has anything to do with the 4510, but I can be wrong.


That's all I have for you guys. Hope someone can help me to fix / troubleshoot this..





Hall of Fame Super Gold

What is the exact model of

What is the exact model of your 2960?

Community Member

2960-X seriesC2960x-48FPD-L

2960-X series

C2960x-48FPD-L V01

Hall of Fame Super Gold

Run a TDR on the link to the

Run a TDR on the link to the phone.


Post the output to the TDR and we should be able to help you decipher.

Community Member

SSwitch3#test cable

SSwitch3#test cable-diagnostics tdr int g1/0/16

TDR test started on interface Gi1/0/16

A TDR test can take a few seconds to run on an interface

Use 'show cable-diagnostics tdr' to read the TDR results.

SSwitch3#show cable-diagnostics tdr int g1/0/16

TDR test last run on: June 27 13:39:21


Interface Speed Local pair Pair length        Remote pair Pair status

--------- ----- ---------- ------------------ ----------- --------------------

Gi1/0/16  1000M Pair A     52   +/- 10 meters Pair A      Normal

                Pair B     52   +/- 10 meters Pair B      Normal

                Pair C     52   +/- 10 meters Pair C      Normal

                Pair D     52   +/- 10 meters Pair D      Normal


Hall of Fame Super Gold

Line test looks good.  So Gi

Line test looks good. 


So Gi 1/0/16 goes to this phone?

Community Member

Yes, correct.

Yes, correct.


Or let me say I guess..:)


It's port #16 on this switch...


Not sure what the rest means..

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