I migrate a cisco 2811 with E1 card from ccm to SIP/Elastix. The problem I face is that from time to time, I receive the subject error (around 10% of outgoing calls). Call is going through on next attempt (can be one to 3) or by waiting few seconds before redialing.
The problem happends even when no calls are engaged, incoming or outgoing. On incoming calls, everything is OK.
The ios is C2800NM-SPSERVICESK9-M.
Any hint would be much appreciate.