We have Cisco MX300 registered at Cisco Communication Manager ver 10.5 and we have Polycom VSX 7000 over WAN (configured as standalone using Public IP Address).
When we call from Cisco MX300 to Polycom the call is not successful. Polycom device rings and as they answered, the call disconnect, with error on MX300 screen "Cannot connect to call".
I am supposing this is something related to protocol or codec mismatch. Can any one advise what is fix for it ? what protocol Polycom VSX 7000 supports or should be enabled in Cisco MX300 to complete successful call?