ESS (External Switching Systems)

ESS (External Switching Systems) are the administrative, non-emergency communications systems within the PSAP that serve as external switching systems for telephony and other administrative communications (voice mail, email, instant messaging, etc.). The ESS equipment might be represented by a traditional PBX or other communications gateway.

NENA-INF-040, NENA Managing &amp; Monitoring NG9-1-1 Information Document