SIP message question - Jabber and CUCM

[Iluvteak]

Our setup is this

Jabber --> CUCM --> SBC --> Carrier

Just a generic question here .. when you place a Jabber call how is Jabber communicating with CUCM.     Our phones are SIP and not SCCP.      How is it telling CUCM to create a SIP dialog with the called party ?      

I believe when a Jabber call is placed CUCM is the device that is creating the SIP INVITE including SDP that is sent to the SBC and then the carrier.     In our case our SBC acts as a pass thru for SIP INVITE message.     Am I correct in this assumption, or is Jabber creating the SIP INVITE and CUCM is just passing it on ?     

The more I think about this question the more confused I get!

[Sergio Quezada]

Hello,
Here is the Call Flow via the logs. I have also attached a Call Flow Map image. Hope this helps.

Jabber for Windows Call Flow Analysis Procedure:
https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/jabber-windows/116309-technote-product-00.html

Planning Guide for Cisco Jabber 12.5:

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/jabber/12_5/Planning_Guide/cjab_b_planning-guide-for-cisco-jabber-125/cjab_b_planning-guide-for-cisco-jabber-125_chapter_011.html

Regards,
Sergio Quezada

[Iluvteak]

Thank for reply Sergio.   I'll read thru those in more detail later.    But a quick look at the sample log in that link tells me SIP is not involved at all when you initiate a call from Jabber - Windows.    Its just programming language stuff.    Would you agree ?

CALL_EVENT: evCreated, 0x005B1818, Initial, CC_ATTR_NOT_DEFINED, CC_CALL_TYPE_NONE,
 CalledPartyNumber: , CallingPartyNumber: , CallInstance: -1, Status: ,
 GCID: , IsConference: 0,
 IsCallSelected: 0, CapabilitySet:

What if it was an 8851 SIP desk phone.   Does that phone send any SIP messages to CUCM to initiate a call ?

[Sergio Quezada]

Yes agreed HTTPS call out. Looks to me like you are sending an e.164 call out you PSTN Gateway..

[Iluvteak]

Funny we call it a SIP phone !    It doesn't do any SIP.     Wonder if an 8851 does any actual SIP messaging.

[Jaime Valencia]

It IS a SIP endpoint, get your Jabber, place a call, generate a PRT and look at the logs, OR, place a call from Jabber and then analyze the CUCM traces. You'll see the SIP signaling for the call.

Jabber documentation clearly states ports 5060/5061 are used for SIP/SIPS

[Iluvteak]

Jaime.    So the original answer was wrong your saying?  

Does Jabber create the SIP INVITE that goes to the called party?    Or does CUCM create separate SIP INVITE and kind of act as a B2BUA.    I’ll check logs in CUCM Monday.   

[Roger Kallberg]

Not sure where you have looked, but it definitely generates SIP traffic. Look at the CM traces.

[Iluvteak]

Sergio.   That example was just the call from the link you sent.    Wasn’t my call. 

[Sergio Quezada]

Gotcha....

Have you tried placing a call from CUCM?

Dialed Number Analyzer Service:
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/dna/11_5_1/CUCM_BK_CBA47A6E_00_cucm-dna-guide-115/CUCM_BK_CBA47A6E_00_cucm-dna-guide-115_chapter_010.html?referring_site=RE&pos=1&page=https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/d...

[Iluvteak]

Sure I use DNA a lot.  Great tool.   But my question is about SIP action between Jabber and CUCM.   What are you suggesting to do with DNA ?

[Sergio Quezada]

I found this also should be a good read.

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cuipph/7960g_7940g/sip/7_5/english/administration/guide/ver7_5/sipaxb75.html

[Roger Kallberg · Accepted solution]

Jabber would initiate a SIP conversation with CM, CM would initiate a SIP conversation with you SBC on the SIP trunk that you would have configured in CM for this, then the SBC would initiate a conversation with your service provider. Once signaling is done and dusted the RTP stream for the call will go directly between your Jabber client and your SBC. This in its turn would have another RTP stream for the outbound side of the call that would flow directly between it and your service provider endpoint.

[Iluvteak]

Thx Roger!    That clears it up!    Man lots of B2BUA’s involved in a call.   More than I thought.   I went thru SIP training and the Jabber/CUCM/SBC interaction always escaped me.     Wonder if there is a tool that gathers all the SIP ladders into one screen.    Currently I need to use SBC traces and then the CUCM traces are separate.   Messy. 

[Roger Kallberg]

Load all your traces and debugs into TranslatorX to generate what you ask about.