Cisco Bug: CSCus20387 - CUCM responding to SIP 200 message with different CSEQ number
Sep 30, 2018
- Cisco Unified Communications Manager (CallManager)
Known Affected Releases
10.0(1.10000.24) 10.5(1.10000.7) 10.5(2.10000.5) 8.6(1.20000.1) 8.6(2.10000.20) 9.1(1.10000.11) 9.1(2.10000.28)
Symptom: REINVITE (early offer) sent out before PRACK numbered response is received. When the PRACK numbered response comes in, we send the ACK (for the REINVITE) erroneously thinking the 200 response was for our CSEQ # when it was actually for the PRACK (previous CSEQ #). Conditions: Far end has to send the numbered responses to the original INVITE (CSEQ 101) which prompts our CUCM to send a PRACK (CSEQ 102). The far end should hold all further correspondence to CSEQ 101 until it has acknowledged the PRACK (CSEQ 102), but instead sends a 200 OK (CSEQ 101). Eventually after CUCM has sent a REINVITE (to place the call on hold - CSEQ 103), the far end replies with the reply to PRACK (200 Minimal Impact - CSEQ 102). The CUCM then erroneously responds with ACK (CSEQ 103).
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Bug Details Include
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