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7960 SIP IP Phone registration problem

I have two problems with 7960 IP phone with SIP

image. First, it only gets L2 connectivity if I

insert a hub between the phone and the switch port.

I tried both manual and automatic half/full duplex,

100/10 Mbps settings on the switch without success.

Second, the phone refuses to register with SIP server

although I am sure that I entered correct

"Authentication name" and "Authentication password"

in the phone SIP configuration (password always

changes to 10 * characters, whaterver long it is,

hopefully it is all right). Observing SIP messages

in packet sniffer, it looks like incorrect MD5

hash computed by the phone.

I use the lastest 3.02.02 image.

Sven Ubik E-mail:


Re: 7960 SIP IP Phone registration problem

Often times complex troubleshooting issues are best addressed in an interactive session with one of our trained technical assistance engineers. While other forum users may be able to help, it’s often difficult to do so for this type of issue.

To utilize the resources at our Technical Assistance Center, please visit and to open a case with one of our TAC engineers, visit

If anyone else in the forum has some advice, please reply to this thread.

Thank you for posting.

New Member

Re: 7960 SIP IP Phone registration problem

The first problem sounds like an issue with spanning tree delay (about 30 seconds) and some process in the phone is timing out. On the switch, enable port fast (Cisco), or disable spanning tree for that port.

New Member

Re: 7960 SIP IP Phone registration problem

Concerning the first problem, try to force the speed and duplex of the port and disable the following parameters on the port (they are enabled by default):

- auto trunk mode, using "set trunk mod/port off"

- auto port channel, using "set port channel mod/range off"

Enable the spantree portfast.



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