I have issues with VOICE connectivity between 2 sites in london and singapore. the sites are connected via mpls and have firewalls behind the CE routers permiting IP ANY>ANY. In london i have ASA 5520 and singapore Juniper netscreen 208. Installed AVAYA media gateways 850 in both sites and IP connectivity is fine because the gatways. The problem when singapore dial internal extension in london, singapore can hear london users but london cannot hear singapore. we are using avaya 9630 handsets. Avaya are using it something on the firewalls blocking the traffic. I have checked both firewalls and cant find anything deny logs. i suspect it might be something to do with the juniper firewall. ScreenOS is 5.0.0.
I will appreciate any comments.