Dynamic Subscriber Assignment

The SBC Core supports dynamically assigning a subscriber to any feature server in the network at the time of first registration or in event of a disaster at the previously-assigned feature server. This 'any subscriber any' functionality is supported by providing:

• 3xx support for Registration—The SBCroutes all initial registrations using a FQDN received from the Policy Server. If the receiving server determines that an alternate feature server is better suited to process the registration, it selects an alternate feature server and redirects the registration using 3xx response. SBC reattempts the registration to the address received in contact header of the 3xx response. The Contact address received in the 3xx response along with any known or unknown parameters is used as Request-URI in the redirected request.
  
  
• Routing requests using Service-Route with crank-back to alternate routes—During initial registration, the feature server serving a given IAD is expected to include its own address and the RS address using new URI parameter "x-alt-host". The Service-Route header returned from the feature server also contains a parameter called "x-alt-host" which contains the RS FQDN or IP address and port.When the first feature server fails to respond, the SBCuses the IP and port received in the x-alt-host to route the request.