Use the button to add a new trunk. The SIP Trunk dialog opens – see further.

Use the button to edit properties of the selected trunk. The SIP Trunk dialog opens – see further.

Click the button to delete the selected trunk.

Click the button to save a list of trunks. A standard file browser dialog opens.

Check this box to make this trunk active.

A descriptive name for the trunk.

Specify the domain of the trunk provider.

Specify the IP address or hostname of any proxy server IceWarp Server should use to get to this trunk.

Specify the username supplied by your trunk provider.

Specify the password for the above username.

Specify here how often, in seconds, the IceWarp Server should re-register with the gateway.

Basically, this tells the trunk that the server is still here and available.

Specify here the maximum number of simultaneous calls allowed via this trunk.

Can be useful in limiting bandwidth usage.

Fill in this field incoming calls from the Skype SipToSis to be properly detected.

Contact header is used to register to a SIP gateway (remote SIP server). The remote server contacts us using this Contact header.

Some servers do not accept the original format and strictly require the format as follows: user@127.0.0.1

It is possible to set this value here.

In this case, IceWarp Server will also treat all incoming calls with URIs beginning with 272048628.

For additional information, refer to the Skype Gateway section.

If enabled, the From header of the packets going into the gateway is changed to correspond with the gateway user (given Username is used). Optionally, exact value of the From header can be entered into the text box. The entered value can be in one of the following forms: user or user@domain.

Normally this field should be left un-checked.

This is here in case your gateway provider requires it.

Check this box if one of the following applies:

• The remote gateway can deal only with digits – the domain from the Contact header field is rewritten to the appropriate IP address.

• Your trunk provider requires it.

(Deeper understanding of SIP advantageous.)

Check this box if you want to prevent the trunk from registration.

e.g.: SipToSis (see the Skype Gateway section) behaves as a SIP client. I. e. it is not possible to register but it is used as a trunk. Use this box to deal wit this situation.

Click the button to add/edit a routing rule and rewrite expressions. The Rule dialog opens.

For details about this dialog, refer to the Dial Plan section.

Select a rule from the list and click the button to copy this rule. The Rule dialog opens – here you can change some settings. Useful if you want to create a similar rule.

Click the button to delete the selected condition.

Use the buttons to move the selected condition up or down in the list.

Check this box to restrict the users who can use this gateway to place an outgoing call.

This option is recommended as otherwise you would leave your gateway open to anyone who knows of its existence.

Use the Add button to open the Select Item dialog, allowing you to add accounts and/or domains to the list.

Use the button to specify which user or users the call should be routed to.

1. If no users are specified, IceWarp Server will do nothing with the call request, not even reject it.

2. If one user is specified, IceWarp Server will attempt to route the call to that user.

3. If multiple users are specified, IceWarp Server will attempt to contact all of those users simultaneously, and will wait until either:

• A user accepts the call, in which case it is routed to that user.

• Or all users reject the call or the request times out, in which case IceWarp Server will reject the incoming call.

Use the button to delete the selected user.