Incoming SIP call fails on UC 500

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Jul 2nd, 2010
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I am facing a strange problem with CIsco UC 500. Most calls from  the provider are successful, except for some specific calls.

The UC 500 receives the Invite but then responds with message 500  (internal server error).

I have attached the SIP trace. The UC is at and the  provider's network is

The proxy is in the ACL of the voice source group.

Doing  an external tcpdump I noticed that for the failed calls the proxy is  sending the SIP Invite in an IP fragment and immedately the UC is  generating the Internal error message. Any ideas?

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Alberto Montilla Fri, 07/02/2010 - 02:30
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  • Cisco Employee,

Dear Sir;

Depending on your product UC520 or UC540/60, I suggest you open a case with TAC or SBSC respectively for this case.



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