Symptom
1. Multiple REINVITES triggered by CUBE in a loop towards both peer legs. Each 200OK response from peer-leg leads to the generation of a REINVITE on the other leg.
Sample call-flow: IP phone -- sip -- CUCM -- sip -- CUBE -- sip -- server-group -- ITSP SBC 1 and ITSP SBC2
2. High CPU in CCSIP_SPI_CONTOL process:
qwerty#show processes cpu sorted | ex 0.0
CPU utilization for five seconds: 94%/0%; one minute: 33%; five minutes: 13%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
732 162116 48235 3360 66.10% 22.00% 5.29% 0 CCSIP_SPI_CONTRO
734 14420 38068 378 1.68% 0.59% 0.13% 0 CCSIP_UDP_SOCKET
Will also see an abnormal values for message rate but CPS will not increase paralelly. Outputs to check:
show sip-ua history stats message-rate table
show call history stats cps table
Router can just crash as well depending on the original call volume.
Conditions
This scenario is hit only when the following conditions are true:
1. Server groups are configured on outgoing dial-peer.
2. Element 1 (chosen by server-group) sends a 18X w/sdp followed by 4xx/5xx msg.
Without a 18x msg with SDP received from element 1, CUBE will not trigger REINVITES post call-connect.
Workaround
1. Apply "midcall-signaling passthru media-change" on outgoing dial-peer. For eg:
dial-peer voice 4001
description ++ Outbound Dial Peer - ITSP ++
session server-group 101
voice-class sip midcall-signaling passthru media-change
!
2. Remove Server-groups from the outgoing dial-peer and replace it with multiple dial-peers configured with session target.
Remove:
dial-peer voice 4001
description ++ Outbound Dial Peer - ITSP ++
session server-group 101
voice-class sip midcall-signaling passthru media-change
!
Add:
dial-peer voice 4001
description ++ Outbound Dial Peer 1 - ITSP ++
preference 0
session target ipv4:1.1.1.1
!
dial-peer voice 4002
description ++ Outbound Dial Peer 2 - ITSP ++
preference 1
session target ipv4:1.1.1.2
!
Further Problem Description
Can collect following show command outputs:
show sip-ua history stats message-rate table
show call history stats cps table
If msg rate is abnormally high while CPS is not increasing parallelly, then CUBE might be hitting this bug.
