UC540 behind SR520 - inbound SIP not working, outbound SIP no RTP

Unanswered Question
May 24th, 2010
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Hey guys,

I am putting together a site for a customer with a UC540 (8.0.2) behind an SR520 (12.4(24)t3-ADV-IP-SERV-CRYPTO).  Everything seems to work great in passing data through, but voice is a no go.  From my experience with the SA520, I had to create static routes for the three VLANs from the UC540.  When I went to do this on the SR520, there was already a static route for for the SR520's vlan75.  I went ahead and added and and pointed them toward (UC540's WAN IP) as their gateway.  In addition, I configured port forwarding in NAT to forward all traffic on port 5060 (TCP and UDP) to forward through the SR520 to the UC540 (

SIP trunk - NexVortex

1. Inbound calls - no worky

I removed the two new SIP source groups created by CCA as follows, but the normal one that I usually see (CCA_SIP_SOURCE_GROUP) didn't appear to exist:

UC540(config)#no voice source-group CCA_SIP_SOURCE_GROUP
source ip group CCA_SIP_SOURCE_GROUP does not exist

UC540(config)#no voice source-group CCA_SIP_SOURCE_GROUP_CUE_CME
UC540(config)#no voice source-group CCA_SIP_SOURCE_GROUP_EXTERNAL

Are there other SIP source groups that exist that could be preventing this?

2. Outbound calls - no audio

I usually configure this setup with an SA500 in front.  In those cases, I have to forward RTP traffic in addition to SIP traffic to make audio work.  On the SR520, however, I can't figure out how to add a range of ports and it would be impossible to add several thousand ports into NAT using CCA.  Any help on this one?

Thanks in advance,


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sethschmautz Mon, 05/24/2010 - 15:06
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hey guys,

Should have troubleshot a little longer. The incoming dialing issue was due to me moving faster than the SIP provider.  The phone numbers had not been routed properly.  The outbound audio issue was the fact that I needed to strip the second "c" header with the following set of commands:

UC540(config)#voice class sip-profiles 1
UC540(config-class)#request ANY sdp-header Connection-info remove
UC540(config-class)#response ANY sdp-header Connection-info remove
UC540(config)#voice service voip
UC540(conf-serv-sip)#sip-profiles 1

Hope this is helpful to somebody else.



Steven DiStefano Mon, 05/24/2010 - 15:10
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We love Partners who answer their own questions :-)

And your a good man for sharing that!!!

Other ill find that useful.  I did :-)



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