By directing messages to the appropriate signaling point, the routing mechanism establishes the connection between the calling and the called party.

Message routes pass through a minimum number of intermediate signaling transfer points. Routing at each signaling transfer point is not affected by the message routes used up to the concerned signaling transfer point. If more than one message route is available, signaling traffic is load-shared by the available message routes. Messages related to a given user transaction and sent in a given direction are routed over the same message route.

Routing between functional blocks depends on whether transfer capability is enabled:

  • If transfer capability is enabled, messages can be routed between signaling links, or between a signaling link and the upper layer or signaling network management.
  • If transfer capability is disabled, messages cannot be routed between signaling links, though they can be routed between a signaling link and MTP3 service users or signaling network management.