Aastra Telecom 55I Nortel Proxy/Registrar, SBC or ALG proxy/registrar, Other proxy/registrars

Configuring Network and Session Initiation Protocol (SIP) Features

Network Settings

Nortel Proxy/Registrar

The phone at IP address 10.10.10.10 is configured to register with the proxy at 63.251.195.10. Because it is a Nortel proxy, the configuration must additionally include the "sip nortel nat support" and "sip nortel nat timer" settings, telling the firmware to enhance the protocols with Nortel specific content.

Note: This IP phone uses RTP port 3000 (the default value) since an RTP port was not explicitly configured.

SBC or ALG proxy/registrar

The phone at IP address 10.10.10.20 is configured to register with the proxy at 63.251.195.20. Because the proxy/registrar has session border control (SBC) or application layer gateway (ALG) functionality, no additional IP phone configuration is required.

Other proxy/registrars

The phone at IP address 10.10.10.30 is configured to register with the proxy at 63.251.195.30. Because this proxy/registrar is not a Nortel proxy and has no SBC or ALG functionality, the configuration must additionally include the "sip nat ip" and "sip nat port" settings that contain the public ip address of the NAT router and the port used for call signaling messages. This information is embedded in protocol messages to allow the proxy/registrar to reach the IP phone on the NAT router private network.

NAT router configuration

You must configure the NAT router to allow signaling or media packets containing the various UDP port values to flow between the private and public networks that are separated by the NAT router. In the sample network, the NAT router must not filter packets using ports 3000, 5060, 6060, 16420, and 16430.

Configuring the IP Phones

41-001160-00, Release 2.1, Rev 04 4-17