The call log lists SIP calls made through Internet Gate.
Call logging is by default disabled. It can be enabled on the Log Configuration page, where you also can decide if you additionally want to collect call quality related metrics, send it to a syslog server, etc.
A SIP call will usually generate the following call records in the call log:
Ringing start for [sip:1234@domainx.com 111.111.111.111] -> [sip:5678@domainy 222.222.222.222]
There is only one Ringing start record for a call, even if this call rings several parallel because of call forking.
Start of session M2Qyg67bYjIm: [sip:1234@domainx.com 111.111.111.111] -> [sip:5678@domainy 222.222.222.222]
The Start of session record is created when the call is answered by the called party. M2Qyg67bYjIm is a unique session ID for this call. It is composed of the beginning of the incoming call ID, of the end of the outgoing call ID, and of a hash value of the remaining part of the involved call IDs. The incoming and outgoing call ID will usually be the same, except for special scenarios, e.g. when a back-to-back SIP user agent is involved.
End of session M2Qyg67bYjIm: [sip:1234@domainx.com 111.111.111.111] -> [sip:5678@domainy 222.222.222.222] Duration: 2 sec, Terminate reason: User Request
The End of session record is created when the call is finished. Terminate reason User Request is the regular case, Timeout is an exceptional case if one party of the call does not respond any more.
> Bytes: 11200, Pkts: 56, missing: 0 (max 0), reo.: 0, Jitter avg: 0 ms (max: 7 ms), last PT: 0 (PCMU), CN: no, MOS: 4.40 < Bytes: 13400, Pkts: 67, missing: 0 (max 0), reo.: 0, Jitter avg: 0 ms (max: 0 ms), last PT: 0 (PCMU), CN: no, MOS: 4.40
These two records follow immediately after the End of session record in the log. They are only generated when “including Media statistics” is set up on the Log Configuration page for call logging. They contain results of the RTP packet monitoring which is performed for the RTP streams belonging to this call. The first line contains information about the RTP packet stream from the calling to the called party, the second line contains information about the opposite direction.
The ringing start message has severity level debug.
The start and end of session messages have severity levels notice.
The media statistics messages have severity levels info.
There might also be error messages logged if any errors occur.
By selecting a suitable level for filtering on e.g. a syslog server you can select the level of information you save.