TMC’s Bob Liu and Tom Keating wrote an excellent article on Microsoft and Cisco collaborating on the ICE standard, a technology used to enable VoIP traffic to more easily permeate firewalls in a secure fashion. Currently, session border controllers (SBCs) are useful but not standardized and punching holes in firewalls is not secure. The ICE standard can work with SBCs to allow more easy VoIP deployments in enterprise networks.

ICE isn’t a new protocol. It actually makes use of two other protocols called STUN and TURN, respectively, but it does require additional signaling capabilities to be introduced into the multimedia session signaling protocols. The only new element added to the network architecture are STUN/TURN servers that sit outside of the NAT firewall of the two calling parties, as well as ICE support on the client-side.

“ICE is very simple. It's very lightweight. The other great thing is you don't need to replace your NATs and firewalls," said Russell Bennett, Program Manager of Microsoft's Real Time Collaboration (RTC) Group. He added, "It's not anyone's intellectual property. It's certainly not Microsoft's and it's certainly not Cisco's. It doesn't impose any cost to anybody,” Bennett told TMCnet during a Live Meeting briefing.

He continued by explaining that ICE works with the existing infrastructure. Bennett said, "You don't have to buy a ICE-compatible firewall with an ICE-compatible sticker for instance, so it doesn't impose a cost on anybody. ICE will ship as a feature/function inside of SIP clients going forward - certainly inside of Microsoft SIP clients. So the only new element in the STUN/TURN servers and it doesn't matter who owns them."