Cluster Real Time
	SIP This section explains how Real Time Communication operations work in the CommuniGate Pro Cluster environment.

SIP

The CommuniGate Pro Cluster maintains the information about all its Servers with the SIP Farm option switched on. Incoming UDP packets and TCP connections are distributed to those Servers using regular simple Load Balancers.

The receiving Server detects if the received packet must be processed on a certain Farm Server: it checks if the packet is a response or an ACK packet for an existing transaction or if the packet is directed to a Node created on a certain Server. In this case the packet is relayed to the proper Farm Server:

Packets not directed to a particular Farm Server are distributed to all Farm Members based on the CommuniGate Pro Cluster algorithms and the currently available set of the active Farm Members.

The Farm Members may need to retrieve certain Account information (registration, preferences, etc.). If a Farm Member cannot open the Account (because the Member is a Frontend Server or because the Account is locked on a different Backend Server), the Member uses Inter-Cluster CLI to retrieve the required information from the proper Backend Server.