Incoming calls from other SIP based PBX are rejected "SIP/2.0 500 Internal Server Error"

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Sep 11th, 2009
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I have a UC520 which is connected to an ISTP (SIP Provider). Incoming ang outgoing calls are fine.

If i receive a call from a SIP based PBX the call is rejected for a reason.

If i make the call to the specific SIP based PBX, the call works fine.

From normal phones, e.g my mobile, my home phone or even IP based PBX that uses BRI for outgoing calls everything works fine.

Any suggestions?  I have upload the debug ccsip from my uc520.

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Saurabh Verma Fri, 09/11/2009 - 05:33
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Can you attach the current configuration? It might also be helpful to get "debug voip ccapi default" along with "debug ccsip all".



pentiumdb Fri, 09/11/2009 - 05:48
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Hello all

I removed the access-list from voice source group and now it works.

voice source-group CCA_SIP_SOURCE_GROUP
no access-list 2



Saurabh Verma Fri, 09/11/2009 - 05:54
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The access-list serves to protect the UC 500 setups from toll fraud. Instead of totally removing the access-list, I would recommend that you add SIP PBX's IP address to the access-list.




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