SIP outgoing calls - change port

Unanswered Question

Hi! I have a problem with my ISP and SIP on my 2811.

My number 2922781 register well, I don't have a problem with incoming calls. But outgoing calls fails. ISP's techsupport sayd that problem with source port in my SIP session. My number register on SIP-server like [email protected]:5060, but outgoing call come from different source port and that's why SIP-server reject call. How can I force use only 5060 port for SIP-session?


dial-peer voice 100 pots

destination-pattern 2922781

port 0/2/0


dial-peer voice 101 voip

destination-pattern .T

session protocol sipv2

session target sip-server

dtmf-relay h245-alphanumeric

codec g711alaw

no vad




timer receive-rtp 1200



authentication username login password password

registrar expires 3600

sip-server ipv4:

no transport tcp


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ashok_boin Tue, 06/24/2008 - 00:53
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SIP uses as destination port as 5060 & source port as random. So, I feel it's working as expected only.

Please convey message to your ISP that the source port can't be 5060 which they said the cause of the problem.

Please refer the following link to get understanding about SIP ports (TCP/UDP).,M1



I got debugging of SIP packets. My 2811 send INVITE - UDP packet with src port 59538, dst port - 5060. My ISP sayd that call will be successful only if src port of my UDP will be 5060, because my 2811 was registered on they mediagate with port 5060 and packets from any other ports will be rejected:


SIP/2.0 487 LR2 - User not registered on this client

I find out that diffirent SIP-devices uses diffirent UDP src ports - some of them uses random port from pool, some of them always uses 5060 port. Both of this method is valid (based on SIP protocol description). But some of ISP required to use only 5060 src port. How can I configure 2811 to always send UDP SIP packet from port 5060?

ashok_boin Tue, 06/24/2008 - 09:09
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Unfortunately, there is no specific command to set source port to 5060 as far as I know. I have seend a bind command to bind source ip to a particular interface but didn't have option to set port.

Just have a try with bind command & observe the source port...




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