The CommuniGate Pro SIP Farm® feature allows several Cluster members to process SIP request packets randomly distributed to them by a Load Balancer.
Configure the Load Balancer to distribute incoming SIP UDP packets (port 5060 by default) to the SIP ports of the selected SIP Farm Cluster members. If your Cluster has Frontend Servers, then all or some of the Frontend Servers should be used as SIP Farm members.
To configure the SIP Farm Members, open the General page in the Settings WebAdmin realm and click the Cluster link:
SIP Farm: This setting specifies how the SIP requests should be processed by this Cluster member.
Member: If this option is selected, this Cluster member is a member of a SIP Farm. It processes new requests locally or it redirects them to other SIP Farm members based on the SIP Farm algorithms.
Disabled: If this option is selected, this Cluster member is not a member of a SIP Farm; it will process incoming SIP requests locally.
Relay: If this option is selected, this Cluster member is not a member of a SIP Farm; but when it needs to send a SIP request, it will relay it via the currently available SIP Farm members.
Select this option for Backend Servers that do not have direct access to the Internet and thus cannot send SIP requests directly.
Note: a SIP request can explicitly address some Cluster member (most in-dialog requests do). These requests are always redirected to the specified Cluster member and processed on that member, regardless of the SIP Farm settings.
The CommuniGate Pro Cluster maintains the information about all its Servers with the SIP Farm setting set to Member. 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 Cluster member:
Packets not directed to a particular Cluster member are distributed to all currently available Farm Members based on the CommuniGate Pro SIP Farm algorithms.
To process a Signal, Cluster members may need to retrieve certain Account information (registration, preferences, etc.). If the Cluster member cannot open the Account (because the Member is a Front