Some folks cringe when discussing basing billing off SIP, particularly in a proxy, but...
First thing that is needed in this case is that the proxy needs to record-route itself so it sees the ACK and BYE. Then, to make sure the billing is not started until the call is actually up, a timer needs to be started when the ACK is forwarded by the proxy to the UAS, waiting for lack of a retransmitted 200 OK from the UAS. The value should be something longer than the default suggested retransmit value for the 200 OK. At that point billing can start. The sticky part of this is that the UAS can pick some retransmit value longer than suggested default. Your billing relationship would typically be with the UAC and you couldn't count on what the UAS sets their retransmit timers to. Many other negative scenarios may need to be considered when attempting to base billing off SIP going through a proxy, including UAs that are not well behaved. There are lots of arguments out there against doing billing based off SIP. Good luck. John Hearty Level3 -----Original Message----- From: Robert Chen [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 27, 2001 4:34 PM To: Vikram Varma; 'Shen, Eran '; 'Sip-Implementors (E-mail) ' Cc: [EMAIL PROTECTED] Subject: [Sip-implementors] A question does not have answer??? I want to create CDR in sip proxy server. I have a question: Let's say UA call UB, UB send back 200OK. 1. If I set the connected time as the SIP server get the 200 Ok, how about proxying the 200Ok to UA but failed. If I set the connected time as the SIP server get the ACK, how about proxying the ACK to UB but failed. Also sometimes ACK directly go between UA and UB. SIP server forward a message does not mean another peer will receive it. SIP server get a 200 OK does not mean this call is set up. Right? 2. BYE and BYE OK has the same issue. _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
