HP VCX Software manual NAT keepalive method, NAT timeout for UDP, NAT timeout for TCP

Chapter 5. SIP Configuration

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 Addi- tional SIP Signaling Ports table.

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.

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