Fax Sending - Caller ID


Hello All,

When using fax sending, how do I define what outbound route to use?

  • Customer has 4 analog lines.
  • I’ve setup the customer with 2 trunks. 1 trunk with ports 1,2, and 3 with a fail-over to port 4 only if the first 3 lines are in use (Inbound does not fail over as the fax would pick it up). The second trunk is for the fax line only (Inbound and out).
  • The fourth line is the fax line.
  • I have figured out that if I change the fax line dial plan to _8x. (for example), and strip 1. Then, if I dial 8 before the number it will force the call through the correct trunk. However, it seems there must be a way to define which trunk is used by the VFAX service without dialing 8. Am I wrong?

I don’t think the customer will care too much if the solution is to dial 8, it just seems like there should be a more elegant solution.

Thanks in advance.


Hello dear,
you can make an outbound route and check on this feature in this outbound route “Enable Filter on Source Caller ID” after that you can the extension of the fax in the box opened after enable this feature in this outbound route now you can make the plan 8x. for example and strip 1 and select the trunk that you want the fax to use it and now you can force the fax to use this outbound route knowing that you must put the extension out the other outbound route to force that fax to use this only outbound route.


Thank-you for your reply.

VFAX, the UCM fax sending app, does not have an extension number.


There is no way that I have found other than what you are doing.


I suggest opening a help desk ticket. If nothing else, it may get this addressed as an enhancement request in a future firmware as I see the need for this if it can’t be accomplished at the current time.