[asterisk-dev] Problems with RTCP

Sergey Tamkovich serg at voipsolutions.ru
Thu Nov 20 07:53:42 CST 2008

John Todd wrote:
> While I think it seems natural to add them to the CDR events, I don't  
> think it is the appropriate place because of the problems you mention  
> - RTP paths aren't static.  It is possible to have a call with two or  
> three media streams.  If there was a single CQDR record, how would it  
> be computed?  Do we add all these up?  Ugh.  Many calls also have  
> multiple destination IP addresses involved for the RTP streams - how  
> do we say what this quality information references as far as an  
> endpoint?
Maybe we should look at cisco?

Many of the metrics peered between the two endpoints via RTP, RTCP, or 
RTCP-XR are gathered from both the local and remote sides of the 
originating and terminating endpoints. Only a concise set of these 
metrics is reported in the CDRs produced by the BTS. If the reporting 
BTS controls both endpoints of the call, then only the "local" metrics 
of each endpoint are stored in the CDR. If only one of the endpoints is 
controlled by the reporting BTS, then the local metrics for that 
endpoint and the remote metrics for the other endpoint as peered to the 
endpoint controlled by the BTS are stored in the corresponding CDR.

PS: cisco generates separate CDR per each call leg.
PPS: This topic involves CDR subsystem heavily. It is natural to store 
QoS metrics in CDR. I hope that RTCP processing and storing will have a 
great boost when a new CDR subsystem (CEL or something else) will appear.

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