Default Routing

From NENA Knowledge Base

Default Routing is the capability to route a 9‑1‑1 call to a designated (default) PSAP when the incoming 9‑1‑1 call cannot be selectively routed due to an ANI failure or other cause.

Related Terms:

Default Route

The routing condition that occurs when a 9‑1‑1 call arrives at a switching or routing point with insufficient data to allow normal routing to the correct PSAP.

MSC (Mobile Switching Center) Default Route

The routing condition that occurs when:

  • a wireless 9-1-1 call arrives at an MSC with insufficient data to allow normal routing to the correct PSAP, or
  • all dedicated MSC to Selective Router trunks, primary and secondary routes, are out of service (i.e., trunk failure condition).

MSC (Mobile Switching Center) Trunk Alternate Route

The routing condition that occurs when all trunks from the MSC to SR are out of service and calls need to be routed to the PSAP. The scenario represents an MSC to SR trunk failure condition versus an all trunks busy condition.

Relevant NENA Documents


NENA 03-008, NENA Standard for E9-1-1 Default Assignment and Call Routing Functions