AudioCodes Mediant 2000, User Manual

Page: 347 / 418

Version 5.6 347 November 2008
SIP User's Manual 7. IP Telephony Capabilities
The SAS agent continuously attempts to communicate with the Proxy using the regular
keep-alive method. After the connection is re-established, the SAS agent switches to
pre-Normal mode. In this mode, the SAS agent maintains all terminations of existing
calls while any new SIP call signaling (issued by new INVITE sessions) is transacted
to/from the Proxy server. This is accomplished using the SAS agent's database of
current active calls. After releasing all calls established during Emergency mode, the
SAS agent resumes operating in Normal mode.
For SAS implementation, the primary Proxy server for the VoIP CPE's (e.g., IP phones) is
the SAS agent (i.e., the device itself) while the IP Centrex or IP-PBX is defined as the
secondary Proxy server. For SAS configuration, the device is composed of two different
applications (SAS and Gateway), where each application has its own SIP interface
(UDP/TCP/TLS ports).
„ Configuring the device to use and operate with the SAS capabilities (refer to
''Configuring SAS'' on page
347 )
„ Configuring SAS emergency call routing (refer to ''Configuring Emergency Calls'' on
page
348 )
7.3.1 Configuring SAS
For configuring the device to operate with SAS, perform the following configurations:
„ IsProxyUsed = 1
„ ProxyIP 0 = <SAS agent's IP address, i.e., the device>
„ ProxyIP 1 = <external Proxy server IP address>
„ IsRegisterNeeded = 1 (for the device)
„ RegistrarIP = ‘ ‘
„ SIPDestinationPort = 5080
„ IsUserPhone = 0 (don’t use “user=phone” in SIP URL)
„ IsUserPhoneInFrom = 0 (don’t use “user=phone” in From Header)
„ IsFallbackUsed = 0
„ EnableProxyKeepAlive = 1 (enables keep-alive with Proxy using OPTIONS)
„ EnableSAS = 1
„ SASLocalSIPUDPPort = (default 5080)
„ SASRegistrationTime = <expiration time that SAS returns in the 200 OK to REGISTER
in Emergency mode> (default 20)
„ SASDefaultGatewayIP = < SAS gateway IP address>
„ SASProxySet = 1