we have some trouble with cut voice at the first 2-3 seconds at the beginning of a call to pstn (or other pbx).
The user didn't hear the pstn (or pbx)-site user at the first 3 seconds.
We use CUCM 7.1.3 with different mgcp Voicegateways (2851, 2811 and 3845) latest 12. ios, with 6961, 7975 and 7921.
At some deployments we are directly connected to the pstn over e1 (32 chanels) at other location we are behind an other pbx (also e1 trunks).
QOS is everywhere configured, and we do not have much traffic, and inside calls works fine.
Also we tried the command voice rtp recv-send, without any improvement.
Have someone any suggestions or ideas?
Thanks in advance.