What is "gci" in "Call-Info"?

[Maren Mahoney]

I'm doing some troubleshooting and I can't figure out what the "gci" parameter in the "Call-Info" header field is for. I came up empty looking at RFCs (although it's probably in there...). Does anyone know what this parameter is for?

Examples from SIP message exchange:

Call-Info: <urn:x-cisco-remotecc:callinfo>; security= NotAuthenticated; orientation= to; ui-state= ringout; gci= 1-167032; call-instance= 1
Call-Info: <urn:x-cisco-remotecc:callinfo>; security= Unknown; orientation= to; ui-state= ringout; gci= 2-868654; isVoip; ignore-early-media=true; call-instance= 1

Example from CUCM Trace:

|AppInfo  |StationD:    (0000114) DEBUG whatToDo: line=1 calls=0 limit=4, busy=2. GCI=(2, 5033), cm_PL=(5, 0)

Thanks!

Maren

[Carlo Poggiarelli]

Hi ,

Usually GCI (Global Call Identification) is transported from a ISDN cirtuit to the sip message .

I've seen this in particular on gateways connected to a PSTN E1 circuit when an particular information elements  in ISDN message as been mapped to a Generic Transparency Descriptor (GTD) es GCI that VG passes on SIP Message.

HTH

Regards

Carlo

[Maren Mahoney]

Thank you for the reply. In our case the messages are all-SIP from carrier to phone, so no ISDN. But that it is a global identifier is interesting.

After looking at some more trace files, I think it might be issued by CUCM as they seem to be sequential in the trace file. And for inbound calls they are added at RINGING or SESSION PROGRESS, while for Outbound calls they are in the INVITE. Another piece of evidence for them being issued by CUCM is that the first digit generally corresponds with the node identifier. How interesting!

I'll post here if I find more data. Thank you again, @Carlo Poggiarelli !

Maren

[Carlo Poggiarelli]

Hi Maren,

Is this info logged on CUCM only or you find it also in the CUBE/VG?

Thanks

Cheers

Carlo