[cisco-voip] Expressway - 3rd Party Border Recommendation

[Pawlowski, Adam]

Afternoon all,

	Trying to get some opinion on how (if) you would put up a perimeter to your UCM clusters to bring in 3rd party clients, softphones, etc, that are SIP based and reside outside of your secured LAN? Most of our desktops are on public addresses, not behind any particular hardware firewall, just software on the host. I'm concerned that the host could be compromised, or as seen with some soft clients, they just get harassed by driveby SIP/H.323 scans and calls. 

	I haven't seen any great justification for trying to fence/proxy connectivity to the UCM for Jabber, X-Lite, etc, to the cluster, but general security practice is saying that if you can make it more secure, it is at least worth looking into. 

	I've looked at trying to set the UBE up for proxy/passthrough registrar, and this seems tedious because it doesn't proxy auth and requires dial-peer configuration (making dual usage as a gateway cumbersome). I have heard "use expressway" a few times but have no idea how that would work for 3rd party SIP devices. Other than that, I spent a bit of time looking at stuff from Edgewater, OpenSIPS, etc, but it is not clear to me if any of these products are worth the trouble, and what the Cisco recommended way to go about this is.

	Anyone have any experience or thought in this area? Is this a bad idea? Anything to say about trying to secure potentially 'untrusted' connectivity on a larger scale?

Regards,

Adam Pawlowski
SUNYAB