Check the attachment for the sniffer trace.
There are two call legs for this test call . First call is from cell phone 0416814061 to 0399551409 (ext 1409) on AAEP. (Talk patch is between SBCE A1 interface 10.100.62.10 to CM medpro/MG 10.100.62.17) After this call leg is established . AAEP setup another call to 0399235574 on behalf of caller 0416814061 (talk path is between SBCE A1 inteface 10.100.62.10 to AAEP 10.100.64.11) , then send refer message to CM to request caller to refer to new callee 0399235574.
After this CM send reinvite to both 0416814061 move their RTP connection from original 10.100.62.17 port 2084 to 10.100.62.117 port 2066 . (10.100.62.117 should be another medpro or GW on CM ) server. Also CM send invite to new callee 0399235574 to establish a new call leg from 10.100.62.10 port 45502 to 10.100.62.117 port 2160 . At this point ,both calls are merged together from point of CM server. And Nortel SESM send bye to clear the call which is stabled by AAEP , this is ok , since CM has referred the first call between 0416814061 to 0399551409 to second call between 0416814061 and 0399235574.
CM then send Notify to AAEP that refer event is in 200 ok status, then it send BYE to clear the first call leg between CM and AAEP.
Later we can see from trace that Nortel SESM send BYE message to CM via SBC and SM to drop the second call leg to 0399235574 ,upon receipt this BYE , CM forward it back to SBC to drop the first call leg with 0416814061.
Change the call flow from sbc --> sm --> cm -->sm-->ep to sbc-->sm-->ep.
Internal ext BPOINT failure has been solved by changing PBX display method from UPDATE to REINVITE for DEV EP call routing.
