Symptom

When CUBE receives a SIP call and matches an outgoing dial-peer with a "session server-group" and "sip options-keepalive" configured, the call fails at the CCAPI layer with a "Cause Value" of 188. No outgoing INVITE is sent out to any of the servers that are part of the server group. The incoming INVITE is responded with TRYING and 503 Service Unavailable.

Conditions

1. The outgoing dial-peer has "session server-group" and "sip options-keepalive" configured example: ! voice class server-group 1 ipv4 x.x.x.x preference 1 ! ! dial-peer voice 201 voip description ***Outbound dial-peer from CUBE to CUCM*** translation-profile outgoing 2 destination-pattern +85224044...$ session protocol sipv2 session server-group 1 voice-class sip tenant 200 voice-class sip options-keepalive profile 200 voice-class sip bind control source-interface GigabitEthernet0/0/0 voice-class sip bind media source-interface GigabitEthernet0/0/0 dtmf-relay rtp-nte codec g711ulaw no 2. The "show dial-peer voice summary" indicates that the outgoing dial-peer is UP/UP and Active (if keepalive is configured) cube# show dial-peer voice summary dial-peer hunt 0 AD PRE PASS SESS-SER-GRP\ OUT TAG TYPE MIN OPER PREFIX DEST-PATTERN FER THRU SESS-TARGET STAT PORT KEEPALIVE VRF : 201 voip up up +85224044...$ 0 syst SESS-SVR-GRP: 1 active NA : 3. IOS/XE version 17.6.1a

Workaround

There are three options. 1. Configure the outgoing dial-peer with "session target ip4:", instead of "session server-group". If needed, create a separate dial-peer for each IP of the server group. ! dial-peer voice 201 voip : session target ipv4:x.x.x.x : ! ! dial-peer voice 202 voip : session target ipv4:x.x.x.x : or 2. Remove the "sip options-keepalive" on the dial-peer. or 3. Downgrade to an earlier version This issue was introduced after the commit of CSCvx92872. this fix is required in all the places where the fix of CSCvx92872 is committed. Issue will not be seen where we have the fix of CSCvz80171 is present.

Further Problem Description