Chapter 10. SIP Services

Remote NAT Traversal

If your SIP client is not STUN-capable, you can use the built-in Remote NAT traversal feature of the Telecommuting Module. The client must register on the Telecommuting Module (or through it).

The SIP client needs to re-REGISTER, or respond to OPTIONS packets, rather often for this to work. The exact period for this depends on the NAT-ing device, but 20 seconds should be enough to get across most NAT boxes.

Remote NAT traversal

Switch this function on or off.

Remote Clients Signaling Forwarding

Many SIP servers need to separate signaling to and from remote clients from signaling to and from the SIP Trunk. For this purpose, you can specify which IP address and port the remote clients will connect to. This can’t be the same IP address and port as what the SIP provider uses!

You also specify which IP address the Telecommuting Module will use when it forwards this SIP signaling to the server on the LAN. In this way, the trunk signaling and remote client signaling will be separated for the PBX.

IP Address for Remote Clients

Select which IP address remote clients connect to. This can be the same IP address as is used by the SIP provider, but then you need to select a different signaling port below.

IP Port for Remote Clients

Enter the signaling port to which remote SIP clients should connect. The Telecommuting Module will listen for SIP signaling on this port only for the IP address selected above.

If you select an alias IP address as the address to where remote clients should connect, you can’t enter a port, but must use port 5060 (5061 for TLS connections). If you select an IP address that was entered in the Directly Connected Networks table, you must specify a port.

You cannot select a port that is already in use for something else, or specified in the Additional SIP Signaling Ports table.

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