it's VoIP---PSTN calls. GW is MGCP.
During this period everything were working fine. But now people from IPCC contace center complaints that voice is not listening after some period.
So the problem is intermittent?
first ill recommend you go through this doc, which is really helpful:
if this doesnt help, start some debugging on your gateway: debug mgcp packets and the like. try to hold the call you experience one way voice problem with and resume again see if that help. Are u using ISDN? post show e1/t1 controllers.
Suggest you upgrade to 12.4(3j) and report again. There are many bugs in previous version, check release notes if you want to see some.
And what you say about that GW registers one time to Publisher and during 30minutes-2hours period registers to Subsriber and so on balancing.
Possible software bug, reason why you should upgrade, then if it does that again, investigate why it happens with the appropriate debugs.
Can this problem be with that there is some network problems like storming? What trace in the CCM is more useful for this problem?
Yes, storms are a bad thing and can cause any type of problems. Sorry, I'm not familiar with CCM traces. Suggest you use the router for debug whenever possible as it is more immediate.