Solved: CUBE & CUCM 7.1, outbound call to unknown number returns ringing rather than NU tone

a.leahy · ‎05-12-2011

Hi all

Has anyone else come across this? An outbound call to an invalid number across a SIP trunk returns ringing rather than number unobtainable.

Gateway is configured in Callmanager as a SIP trunk, config is simple and provided by the line provider with the following extract:

voice service voip
allow-connections sip to sip
sip
midcall-signaling passthru

dial-peer voice 91 voip
destination-pattern 9T
voice-class codec 1
session protocol sipv2
session target ipv4:x.x.x.x
no vad

There is no SIP-UA configuration.

When making the outbound call the SIP responses indicate an unknown message:

Send 100 - trying
Receive 183 - Session Progress
Receive 404 - Not found

I'm guessing this needs some SIP Profile config?

Thanks in advance for any assistance.

Andy

Andrew Latamore · ‎05-16-2011

Hi Andy,

I believe the problem here is with your service provider. Since you are getting back a 183 Session In Progress after the 100 Trying I would guess you are using early offer (which means you are sending an SDP with media negotiation parameters in your Invite message). What this means is that when they send back 183 Session In Progress, you are getting audio cut through. The ringing you hear at that point it most likely to be coming from your service provider. They then send 404 Not Found, but this occurs after the 183 and media cut through. They should be sending the 404 directly after the 100. I am guessing they are cutting through the early media from their system, then getting the service unavailable back from their upstream connection. They then pass that on to you, causing the problem. As you can see from the following SIP call flow document, they should be sending the 404 directly after the 100.

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_programming_reference_guide_chapter09186a0080087348.html#xtocid1

I would inquire with them about this problem. Even if the CUBE/CUCM respects the 404 Not Found message, you would still hear ringing for the period in which media cut through occurs after the 183 Session In Progress. I hope this helps!

-Andy

View solution in original post

Andrew Latamore · ‎05-16-2011

Hi Andy,

I believe the problem here is with your service provider. Since you are getting back a 183 Session In Progress after the 100 Trying I would guess you are using early offer (which means you are sending an SDP with media negotiation parameters in your Invite message). What this means is that when they send back 183 Session In Progress, you are getting audio cut through. The ringing you hear at that point it most likely to be coming from your service provider. They then send 404 Not Found, but this occurs after the 183 and media cut through. They should be sending the 404 directly after the 100. I am guessing they are cutting through the early media from their system, then getting the service unavailable back from their upstream connection. They then pass that on to you, causing the problem. As you can see from the following SIP call flow document, they should be sending the 404 directly after the 100.

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_programming_reference_guide_chapter09186a0080087348.html#xtocid1

I would inquire with them about this problem. Even if the CUBE/CUCM respects the 404 Not Found message, you would still hear ringing for the period in which media cut through occurs after the 183 Session In Progress. I hope this helps!

-Andy

a.leahy · ‎05-16-2011

Hi Andrew

Great answer, thanks for your time.

Andy