[SR-Users] why is rtpenengine-delete deleting the whole call?

[Juha Heinanen]

i noticed one more things during testing of rfuchs/delete-branch, which
i don't quite understand.

the test call is parallel forked to two destinations and offer (using
via-branch=1) is issued for both.  thus the offers have the same params:

... "call-id": "138d9b5516741c30", "via-branch": "z9hG4bKe8998a18295855da", "received-from": [ "IP4", "192.98.102.10" ], "from-tag": "b5b2ffd6a2205b13", "command": "offer" }

..."call-id": "138d9b5516741c30", "via-branch": "z9hG4bKe8998a18295855da", "received-from": [ "IP4", "192.98.102.10" ], "from-tag": "b5b2ffd6a2205b13", "command": "offer" }

then i decline one branch and rtpengine-delete is called (using
via-branch=1):

Dec  4 01:24:02 lohi rtpengine[10306]: [138d9b5516741c30] Received command 'delete' from 127.0.0.1:52496
Dec  4 01:24:02 lohi rtpengine[10306]: [138d9b5516741c30] Dump for 'delete' from 127.0.0.1:52496: { "call-id": "138d9b5516741c30", "via-branch": "z9hG4bKe8998a18295855da", "received-from": [ "IP4", "192.98.102.10" ], "from-tag": "b5b2ffd6a2205b13", "command": "delete" }
Dec  4 01:24:02 lohi rtpengine[10306]: [138d9b5516741c30] Scheduling deletion of call branch '' (via-branch 'z9hG4bKe8998a18295855da') in 30 seconds

30 secs later i get to syslog:

Dec  4 01:24:32 lohi rtpengine[10306]: [138d9b5516741c30] Call branch '' (via-branch 'z9hG4bKe8998a18295855da') deleted

then 10 seconds later i answer the second branch and call
rtpengine-answer using via-branch=2:

Dec  4 01:24:42 lohi rtpengine[10306]: [138d9b5516741c30] Received command 'answer' from 127.0.0.1:44490
Dec  4 01:24:42 lohi rtpengine[10306]: [138d9b5516741c30] Dump for 'answer' from 127.0.0.1:44490: { "sdp": "v=0#015#012o=- 1362734666 2118038312 IN IP4 10.0.2.15#015#012s=-#015#012c=IN IP4 10.0.2.15#015#012t=0 0#015#012a=tool:baresip 0.4.15#015#012m=audio 10986 RTP/AVP 96 97 0 8 101#015#012b=AS:128#015#012a=rtpmap:96 opus/48000/2#015#012a=fmtp:96 stereo=1;sprop-stereo=1;maxaveragebitrate=28000#015#012a=rtpmap:97 speex/8000#015#012a=fmtp:97 mode="3";vbr=off;cng=on#015#012a=rtpmap:0 PCMU/8000#015#012a=rtpmap:8 PCMA/8000#015#012a=rtpmap:101 telephone-event/8000#015#012a=fmtp:101 0-15#015#012a=sendrecv#015#012a=label:1#015#012a=rtcp-rsize#015#012a=ssrc:49929059 cname: ...
Dec  4 01:24:42 lohi rtpengine[10306]: [138d9b5516741c30] ... sip:jh at test.tutpro.com#015#012a=rtcp-mux#015#012a=ptime:20#015#012", "ICE": "force", "replace": [ "session-connection", "origin" ], "call-id": "138d9b5516741c30", "via-branch": "z9hG4bKe8998a18295855da", "received-from": [ "IP4", "192.98.102.10" ], "from-tag": "b5b2ffd6a2205b13", "to-tag": "14f16e4bb432882f", "command": "answer" }

question: how it is possible the call works, i.e., rtpengine still has
the call even when it was already deleted?  does it remember that two
offers were made using same params and the call does not really get
deleted before it has received two deletes?

-- juha