Polycom DOC2702A User Manual

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Polycom RealPresence Collaboration Server (RMX) 1500/2000/4000 Administrator’s Guide
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Polycom, Inc.
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
ICE is available in MPM+ Card Configuration Mode (Version 7.0 and later) and MPMx 
Card Configuration Mode (Version 7.1 and later).
RMX 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 MCU must have a unique account in the Active Directory and must be registered 
with the Office Communications/Lync server.
From Version 7.8, ICE is supported with MCU Multiple Networks.
Ensure that the MCU 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 MCU 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. 
Figure H-2
ICE Environment
Local connection - a connection between the MCU and endpoints that reside within the same 
organization. For example, an endpoint in Zone A calls the MCU in Zone A.
Branch Office - a connection between an endpoint that is behind a firewall and the MCU that 
reside in the same zone. The user in the Branch Office can also place and receive calls from 
other enterprises and remote users. For example, Enterprise A also contains a branch office, 
which in this example is a Polycom HDX user who is behind more than one firewall. 
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.