$Revision: 1.5 $ Copyright (c) 2006 Xygnanda Technology, Inc. This is the End of Call Protocol between mgd and boost. It is assumed that all calls are in the answered/talking phase when the end of call procedures described below are executed. There are three End of Call causes: 1) Initiated by the remote SS7 node sending REL 2) Initiated by MGD sending CallStop 3) Initiated by MGD sending CallStop and the remote SS7 node sending REL simultaneously The protocol assumes a reliable and low latency communication medium between ss7boost and sangoma_mgd. Reliability may come through use of SCTP. Low latency will come through continual monitoring and alerts on events that violate latency requirements. Latency could me monitored through timestamping all transaction start messages. Each transaction response would return the timestamp from the transaction start message. The transaction initiator would check the transaction latency and report any violation. The latency violation limits are to be determined. 1.a) Remote SS7 node initiated end of call; Normal MGD ss7boost rmt SS7 node | | | | | REL | | |<---------------------| | Msg-A | | |<---------------| | | Msg-B | | |--------------->| | | | RLC | | |--------------------->| | |* ckt ready for reuse | | | | Notes: i) if REL CIC is bound to a call that is being set up, then Msg-A is a CallStartNack and Msg-B is a CallStartNackAck ii) if REL CIC is bound to a call that is established, then Msg-A is a CallStop and Msg-B is a CallStopAck iii) if REL CIC is not bound to any call, then Msg-A is not sent since MGD has no resources consumed and Msg-B is not expected in return 1.b) Remote SS7 node initiated end of call; delayed EoCA, ISUP T1 expiry MGD ss7boost rmt SS7 node | | | | | REL | | |<---------------------| | Msg-A | |\ |<---------------| | \__T1 | | | / | | REL |/ | |<---------------------| | | |\ | | | \__T1 | | | / | | REL |/ | |<---------------------| | | |\ | | | \__T1 | | | / | | REL |/ | |<---------------------| | Msg-B | | |--------------->| | | | RLC | | |--------------------->| | | | | | | Notes: i) 1.a.i-iii apply ii) ignore any message from SS7 side for this CIC after Msg-A is sent 1.c) Remote SS7 node initiated end of call; delayed or missing EoCA, ISUP T5 expiry MGD ss7boost rmt SS7 node | | | | | REL | | |<---------------------|__________ | Msg-A | |\ \ |<---------------| | \__T1 \ | /| | / \ | / | REL |/ | | / |<---------------------| | | | | |\ | | | | | \__T1 | | Tcsa | | / | | | | REL |/ | | | |<---------------------| | | | | |\ | | \ | | \__T1 | | \ | | / | | \| REL |/ | | * see Note (i)/|<---------------------| | | / | |\ | | / | | \__T1 | | | | | / | | | | REL |/ T5 | Tcsa |<---------------------| | | | | |\ | | | | | \__T1 | | | | | / | | \ | REL |/ | | \ |<---------------------| | | \| |\ | | /| | \__T1 | | / | | / | | / | REL |/ | | | |<---------------------| | | | | |\ | | Tcsa | | \__T1 | | | | | / / | | | REL |/ / | | |<---------------------|__________/ | \ | RSC | | \ |<---------------------| | \| |* see Note (ii) | | | Notes: i) issue warning on Teoca expiry ii) rmt SS7 node will send ckt reset and remove ckt from use; this cycle will repeat at the remote SS7 node upon each expiry of T17 iii) see reset circuit protocol document for more detail on how this procedure continues vi) this process could go on indefinitely; manual intervention required; manual resolution process to be defined v) 1.a.i-iii apply vi) ignore any message from SS7 side for this CIC after Msg-A is sent 2.a) MGD initiated end of call; normal MGD ss7boost rmt SS7 node | | | | Msg-A | | |--------------->| | | | REL | | |--------------------->| | | | | | RLC | | |<---------------------| | Msg-B | | |<---------------| | | | | | | | Notes: i) if Msg-A is a CallSetupNack then Msg-B will be a CallSetupNackAck ii) if Msg-A is a CallStopped then Msg-B will be a CallStoppedAck 2.b) MGD initiated end of call; ISUP T1 expiry MGD ss7boost rmt SS7 node | | | | Msg-A | | |--------------->| | | | REL | | |--------------------->| | /| | | T1__/ | | | \ | | | \| REL | | |--------------------->| | /| | | T1__/ | | | \ | | | \| REL | | |--------------------->| | | RLC | | |<---------------------| | Msg-B | | |<---------------| | | | | Notes: i) 2.a.i-ii apply 2.c) MGD initiated end of call; ISUP T5 expiry MGD ss7boost rmt SS7 node | | | | Msg-A | | |--------------->| | | _______________| REL | | ^ /|--------------------->| | | T1__/ | | | | \ | | | | \| REL | | | /|--------------------->| | | T1__/ | | | | \ | | | | \| REL | | | /|--------------------->| | | T1__/ | | | T5 \ | | | | \| REL | | | /|--------------------->| | | T1__/ | | | | \ | | | | \| REL | | | /|--------------------->| | | T1__/ | | | | \ | | | | \| REL | | ___V___________|--------------------->| | |* see Note (i) | | | | Notes: i) Msg-A will be either CallStopped or CallSetupNack ii) execute T5 expiry procedure described in the circuit reset protocol document iii) circuit may be unusable until condition is cleared either automatically or manually by the remote SS7 node 2.d) MGD initiated end of call; MGD Tcsa expiry MGD ss7boost rmt SS7 node | | | | Msg-A | | |--------------->| | |_________ |* msg lost in ss7boost| | ^ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tcsa | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |____V____ | | |* see Note (i) | | | | | Notes: i) on expiry of Tcsa in MGD, issue warning to mtc personnel ii) condition probably requires manual intervention iii) manual intervention process is to be determined vi) this procedure overlays on the procedure described in 2.c above Appendix A - Protocol Diagram Template --------------------------------------------------------- MGD ss7boost rmt SS7 node | | | |<---------------| | | | | |--------------->| | | | | | |--------------------->| | | | | |<---------------------|