NEC Sl2100 Networking Manual page 73

ISSUE 1.0
5.1 Address Resolution
If using any SIP Proxy Server, the NEC SL2100 always sends messages to an external SIP server.
If not using any SIP Proxy Server, the NEC SL2100 uses the internal address table (Program 10-23 :
SIP System Interconnection Setup).
When a user creates an interconnection network with SIP trunks, Program 10-29-14 : SIP Server
Information Setup - SIP Carrier Choice must be set to 0 (default).
5.2 Authentication Process
When using an external SIP Server provided by a carrier, an authentication process is usually needed.
NEC SL2100 SIP trunks support HTTP digest authentication process (MD5). This process is done on
a Register process and Initial INVITE process.
5.3 Caller ID
Caller ID for SIP Trunks is set by Program 21-17 : IP Trunk (SIP) Calling Party Number Setup for
Trunk.
Caller ID for SIP Extensions is Program 21-19 : IP Trunk (SIP) Calling Party Number Setup for
Extension.
Programs follow program priority as follows: 21-19 > 21-17 > 10-36-02
With a trunk-to-trunk transfer and Trunk-to-Trunk Outgoing Caller ID Through Mode enabled (Program
14-01-24), the Caller ID/sub-address (received from the incoming trunk) is sent. If a SIP trunk is
connected to any SIP carrier, the sub-address is not transferred.
Calling Party Name is not provided for outgoing calls on SIP trunks.
5.4 Carrier Support
If a common carrier supports SIP, the NEC SL2100 can connect:
• the SIP Carrier
• the outgoing call to the PSTN network
• the common IP network via an NEC SL2100 SIP trunk.
A conformity test with a carrier's SIP server is recommended.
5.5 Early Media
When the NEC SL2100 receives the response 18x w/SDP and the CODEC negotiation is a success,
the NEC SL2100 starts to send/receive RTP packets.
5.6 Fault Tolerance
When the NEC SL2100 uses an external SIP Server and if the registration process fails, the NEC
SL2100 blocks outgoing calls with SIP trunks. All SIP trunk ports are placed into a busy status.
If the NEC SL2100 has trunk groups that include both SIP trunks and ISDN trunks, and all SIP trunks
are busy, a user can make an outgoing call using an ISDN trunk as a bypass.
Networking Manual
SL2100
7-5