when a call comes from outside over SIP trunk to a local phone it sometimes takes a very long time for the call to be established. The called phone already rings and the called phone answers, while on the other side (outside calling phone) it is still saying "Connecting" and no Ringback is heard. Then suddenly the connection is established and the call goes on normally.
The setup is as follows:
Provider SIP trunk --- PIX --- To Call Manager
I suspect that PIX causes this occasional long call setup, but i do not know how to fix this. Anyone managed to solve this before?