SIP over MS ICA?

[mgraves]

Does anyone here know the magic required to get a SIP phone working behind MS ICA firewall? My employer just switched to this from an old Checkpoint firewall. I need to advise our net admin how to get a couple of Polycom phones working with a hosted PBX.

The most obvious settings seem to support the MS variety of SIP over TCP. Our handsets are normal SIP, signaling over TCP and RTP streams over UDP.

Michael

[Brandon]

You mean ISA? Doing a quick search it seems like a NATing issue, but I'm not sure.

Are you connecting from outside in, or vice-versa?

We currently use SIP trunks that don't enter via the Internet, so I've never delt with ISA and SIP traffic -_-.

[mgraves]

Yeah, it's ISA.

I'm in Houston. The firewall and the phone are in Cambridge, UK under the admin of someone else. Since we just installed ISA he's still learning about its administration.

It probably is just port a forwarding issue, but he doesn't seem to be able to work it out.