SR (Selective Router)

SR (Selective Router) is the Central Office that provides the tandem switching of 9-1-1 calls. It controls delivery of the voice call with ANI to the PSAP and provides Selective Routing, Speed Calling, Selective Transfer, Fixed Transfer, and certain maintenance functions for each PSAP.

a.k.a.

9-1-1 Selective Routing Tandem

9-1-1 Tandem

E9‑1‑1 (Enhanced 9‑1‑1) Control Office

E9‑1‑1 (Enhanced 9‑1‑1) tandem Office


 * NENA-STA-027, NENA E9-1-1 PSAP Equipment Standards
 * NENA 03-003, NENA Recommendation for the implementation of Inter-Networking, E9-1-1 Tandem to Tandem