RealPresence Collaboration Server (RMX) 1500/1800/2000/4000 Administrator’s Guide
Polycom®, Inc. 1004
Interactive Connectivity Establishment (ICE)
Interactive Connectivity Establishment (ICE) provides a structure/protocol to unify the various NAT
Traversal techniques that are used to cross firewalls.
It enables SIP based endpoints to connect while traversing a variety of firewalls that may exist between the
calling endpoint (local) and the MCU or called endpoint (remote). It is the only way for remote Microsoft
Office Communicator/Lync users to call into the enterprise without a VPN.

ICE Guidelines

●Collaboration Server ICE implementation complies with Microsoft ICE implementation.
●ICE is available only in IPv4 environment.
●ICE can be implemented in an environment that includes a STUN server and a Relay server (for
example, Microsoft AV Edge server).
●The firewall must be UDP enabled.
●The Collaboration Server must have a unique account in the Active Directory and must be registered
with the Office Communications/Lync server.
●ICE is supported with Collaboration Server Multiple Networks.
●Ensure that the Collaboration Server system SIP signaling domain has been allowed on the Lync
Server edge server to which you are federating (if your deployment does not include a DMA system).
●Content sharing (BFCP protocol) is not supported in ICE environment.

Connecting to the Collaboration Server in ICE Environment

The dialing methods that can be used by an endpoint to connect to another endpoint depends on the ICE
environment: Local, Remote or Federation.
ICE Environmen
I
Local connection - a connection between the Collaboration Server and endpoints that reside within the
same organization. For example, an endpoint in Zone A calls the Collaboration Server in Zone A.
When ICE over UDP is blocked in the firewall UDP port, the ICE connection through the TCP
protocol is automatically used instead of UDP for fallback.