IP Trunk Assistant

The IP Trunk Assistant page offers simplified IP trunk configuration. This page shows a list of IP trunk accounts created from this interface, with the capability to create, update and/or delete SIP/IAX trunks as well as the capability to enable/disable them. 

Before you start creating SIP trunks, ensure you verify the following:

See External SIP Trunk - Configuration Checklist for details.

To access the page, perform the following steps:

  1. Open the UCx Web-based Configuration Utility
  2. From the PBX tab, select IP Trunk Assistant

Adding a New Account

To add a new trunk account, perform the following steps:

  1. Press the New Account button
  2. Enter a unique name for this account in the Account Name field (it is recommended to NOT use spaces in the name)
  3. Select the far-end IP trunk provider or system in the Trunk Provider drop down list box
  4. For the next two fields User Name and Secret:
    • ​​ If registration based authentication is used for this trunk, then enter the user name and password that you received from the IP trunk provider
    • If IP-based authentication is used for this trunk, these two fields are disabled
  5. Optionally, you can enter the desired outbound caller ID number in the Outbound CallerID field
  6. In the Host / IP field, check and update the value to match the far-end host IP address. You can add a port number to the address suffixing with a colon followed by the port number. (e.g.
  7. Press the Save button to create the new account
  8. The corresponding trunk for this account is automatically created and immediately enabled (there is no need to go to the PBX Configuration page to apply configuration changes).
  9. You can view the details of the trunk created by going to PBX Configuration - Trunks page.

When you select from the Trunk Provider drop down list, the corresponding configuration details for the selected provider or system are pre-filled with default values. These pre-configured values have been tested and verified by E-MetroTel. If a custom trunk provider is selected, then you will need to manually fill in the required fields. (For list of verified trunk providers, see SIP Trunk Configuration (verified SIP providers) page).

If you decide to change some of the pre-configured defaults, please make sure you understand the purpose of the modified fields and values you entered.

Configuration Details

The following table provide a description of the fields in the Configuration Details box.

Field Common Settings Description
Type peer

peer means this is a SIP entity to which UCx sends calls (e.g. a SIP provider).
user means this is a SIP entity which places calls through UCx ((e.g. a phone which can place calls only)
friend means the entity is both a user and a peer.

Qualify yes yes means that the UCx system will periodically send a request that the other system identify itself. If there is no answer within 2 seconds,UCx will assume that the other system is down and stop sending calls to the system until it responds.
Insecure port,invite port means to accept incoming calls even if they come from a port other than the one where calls are expected to come from.
invite means to accept incoming calls even if they are not accompanied by the proper username and password.
Most trunk providers require these settings.
DTMF Mode rfc2833 rfc2833 is the most common method for sending DTMF. The other methods are inband and info.
auto means to use rfc2833 if offered, inband otherwise.
Technology SIP This is the protocol to use for this trunk, you can choose between SIP and IAX2.
Can Reinvite nonat yes means to allow reinvites for the purpose of setting up direct media path.
no means do not allow reinvites for the purpose of setting up direct media path.
nonat means to alllow reinvites when local and deny reinvites when there is NAT.
update means to use UPDATE instead of INVITE.
Send RPID yes yes means to send the Caller ID on outgoing calls using the Remote-Party-ID header.  If your outgoing calls are always rejected, you may want to set this to no.
pai means that your system will send the Caller ID on outgoing calls using the "P-Asserted-Identity" header.  If your outgoing calls have an incorrect Caller ID, you may want to use this setting.
Trust RPID yes yes means to look at the Remote Party ID header for the Caller ID on received calls instead of the from field of the incoming call.
DTLS-SRTP no To enable DTLS-SRTP for this trunk, the systems on both ends must support it and DTLS certificate is required. See DTLS Certificate for details.
ICE no Enabling ICE support is recommended only in cases when there are issues with NAT traversal due to complicated multiple router configurations. See ICE support for details.
Host / IP   Hostname / IP address of the remote system that you are connecting to. Optionally, the SIP port number used by the host can also be included. Ex: dallas.voip.ms,
Context from-trunk

from-trunk means that incoming calls from this trunk will be treated as if they are coming from an outside line, and will be routed using the rules that you setup in the Inbound Routes module. Use this setting if the provider is sending the DID number in the INVITE line, this is the most common setting. Use this setting for IAX trunks.

from-pstn-toheader means that incoming calls from this trunk will be treated as if they are coming from an outside line, and will be routed using the rules that you setup in the Inbound Routes module. Use this setting if the provider is sending the main account number in the INVITE line and the actual DID number in the TO: header line, this condition is not common and only used by certain providers.

from-internal means that incoming calls from this trunk will be treated as if they were made by an internal phone, and will be routed directly to an extension number, a feature code, or through the outbound routes module.

Disallow all The value all tells the system to not use any audio codecs unless they are expressly allowed in the Allow field.
Allow ulaw,alaw Enter the codec(s) that are allowed.  This takes effect only if Disallow is set to all.
From User   The value entered in this field replaces the Caller ID in the from field of the call. If the remote system expects the Caller ID to appear in the from field, you should leave this field blank. 
From Domain   The value entered in this field replaces the domain name in the from field of the call. 

Managing Accounts

You can use the IP Trunk Assistant page to manage configured IP trunk accounts:

  • To delete an account, select the checkbox on the left side of the account list and press the Delete button
  • To edit the account configuration data, select the Edit link in the Action column
  • To enable and disable the account, select the Disable/Enable link in the Action column

If your trunk provider does not appear in the Trunk Provider drop down list box, you can add accounts from other providers by selecting custom in the Trunk Provider field.

Making Custom Modifications

The IP Trunk Assistant provides SIP Trunk Settings that work for Specific SIP trunk providers.  Occasionally, the need arises to create a custom SIP trunk configuration that requires a SIP setting not provided for by our IP Trunk Assistant.  
To accomplish this you will need to create the trunk manually in the GUI on the PBX-->Configuration-->Basic-->Trunks page. However, if you have a trunk that was created using the IP Trunk Assistant and you want to modify it manually, you can save a bit of effort by duplicating the trunk that was created using the IP Trunk Assistant and modifying that trunk through the PBX/Configuration/Basic/Trunks page.  When you are satisfied with the modifications you can delete the trunk in the IP trunk Assistant.  The steps to accomplish this:

  1. Login to the UCX GUI.
  2. Navigate to the PBX-->Configuration-->Basic-->Trunks page
  3. Select the trunk, created by the IP Trunk Assistant that you want to modify.
  4. Press the Duplicate button at the bottom of the page.  This will create a second trunk that has the same name but is disabled by default.
  5. Select the duplicated disabled trunk and give it a new unique name.  The press Submit and Apply Changes.
  6. Navigate to the IP Trunk Assistant page.
  7. Disable the SIP trunk that you duplicated in Step 4 of this procedure.
  8. Navigate back to the PBX-->Configuration-->Basic-->Trunks page, select the duplicated trunk and enable it.
  9. You can now customize this SIP trunk as needed.
  10. When you are satisfied with your changes and have a working customized SIP trunk, you can then delete the original Trunk created using the IP Trunk Assistant.

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