Load Balancer Oracle Fusion Middleware Online Documentation Library

7-2 Oracle WebLogic SIP Server Container Administrators Guide Figure 7–1 Oracle WebLogic Server SIP Container Architecture

7.2 Load Balancer

Although it is not provided as part of the Oracle WebLogic Server SIP Container product, a load balancer or multiple load balancers is an essential component of any production Oracle WebLogic Server SIP Container installation. The primary goal of a load balancer is to provide a single public address that distributes incoming SIP requests to available servers in the Oracle WebLogic Server SIP Container engine tier. Distribution of requests ensures that Oracle WebLogic Server SIP Container engines are fully utilized. Most load balancers have configurable policies to ensure that client requests are distributed according to the capacity and availability of individual machines, or according to any other load policies required by your installation. Some load balancers provide additional features for managing SIP network traffic, such as support for routing policies based on source IP address, port number, or other fields available in SIP message headers. Many load balancer products also provide additional fault tolerance features for telephony networks, and can be configured to consistently route SIP requests for a given call to the same engine server on which the call was initiated. In a Oracle WebLogic Server SIP Container installation, the load balancer is also essential for performing maintenance activities such as upgrading individual servers Oracle WebLogic Server SIP Container software or hardware or upgrading applications without disrupting existing SIP clients. The Administrator modifies load balancer policies to move client traffic off of one or more servers, and then performs the required upgrades on the unused server instances. Afterwards, the Administrator modifies the load balancer policies to allow client traffic to resume on the upgraded servers. Oracle provides detailed information for setting up load balancers with the Oracle WebLogic Server SIP Container engine tier for basic load distribution. See Section 3.2, Oracle WebLogic Server SIP Container Base Platform Topologies 7-3 Configuring Load Balancer Addresses to configure a load balancer used with Oracle WebLogic Server SIP Container.

7.3 Engine Tier