Chapter 5. SIP Configuration

Except this from translation

Enter the DNS name or IP address to be excepted from IP address translation. If you enter a DNS name, the corresponding IP address will be excepted from translation.

Delete Row

If you select this box, the row is deleted when you click on Add new rows, Save, or Look up all IP addresses again.

Create

Enter the number of new rows you want to add to the table, and then click on Create.

Remote SIP Connectivity

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 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. It is not advisable to use OPTIONS for 3Com SIP clients.

Remote NAT traversal

Turn this function on or off.

Re-REGISTER period for clients

Clients using this function will have to re-REGISTER very often, to keep the IP/port NAT binding. A re-REGISTER interval of 20 seconds should be enough to ensure this.

If some clients are unable to handle short re-REGISTER intervals, the Telecommuting Module can send OPTIONS messages instead, see below.

Use OPTIONS for registered clients

Select if the Telecommuting Module should use OPTIONS packets instead of short re-REGISTER intervals to keep the NAT binding.

OPTIONS should not be used for 3Com phones, as they don’t respond to that.

OPTIONS interval

Enter the interval for the Telecommuting Module to send OPTIONS packets to the client.

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