Chapter 10. SIP Services

Forward Signaling from IP Address

Select which IP address the Telecommuting Module should use as the sender IP address when forwarding signaling from remote clients.

As all other SIP signaling will be forwarded using the IP address entered in the Directly Connected Networks, you must select an Alias IP address here.

NAT keepalive method

Clients using this function will have to send SIP packets very often, to keep the IP/port NAT binding. Select which method to use to force the clients to send packets frequently.

OPTIONS are sent from the Telecommuting Module to the client, and the client is required to respond to these OPTIONS packets to keep the NAT binding.

With short registration times, the Telecommuting Module tells the client to register with shorter intervals than it normally should have used, to keep the NAT binding. This will load the SIP registrar as well (if the Telecommuting Module is not the registrar), but is a method supported by all SIP clients.

NAT timeout for UDP

Enter the timeout the NAT box uses for UDP connections. The Telecommuting Module uses this information when deciding the intervals with which to send OPTIONS or tell the client to re-register.

NAT timeout for TCP

Enter the timeout the NAT box uses for TCP connections. The Telecommuting Module uses this information when deciding the intervals with which to send OPTIONS or tell the client to re-register.

Media Route

Usually, media is always sent via the Telecommuting Module when the Remote NAT Traversal feature is used. For clients behind the same NAT, media can be made to go directly between the clients, to lower the Telecommuting Module and network load.

184