ATA to temporarily use another phone line


Hi all. Is it possible with one of the ATAs to temporarily use another phone line? Allow me to go a little further with this. My company services office equipment (MFP, Fax, etc.). I have a UMC6204 with 3 voice lines and 1 fax line. I want to be able to use one of my open voice lines to send/receive a test fax to my fax machine and send/receive to another fax in my office. Another thought is could I do that with the second fxs port on the UMC? Thanks for any thought you have on this.


What model of ata is it?
anyway on the 2 ports you can program them individually TRUNK/TRUNK - TRUNK/EXTENSION etc…


I do not have an ATA yet, just wondering if that might work. Sorry I new to PBX programming so I need to dumb it down a bit to make sure I get it. So here I have voice 1, voice 2, voice 3 and fax 1. Voice 1, 2, and 3 are incoming/outgoing voice lines and roll over to each other. My fax line in connected to fxs 1. I can program my second fxs port to fax in/out on voice 3 and not interfere with it being used as a rollover or voice use?


first of all you have to know at least the basic settings of the ATA otherwise it will be an adventure, I can rejoin YES but it would take an entire evening to address the subject.
An ata has a “low” number you’d better buy one and play with it a little.


It would be one of the GS ATA for sure. I understand about the long explanation though.



I’ll do some more research on that. Thanks.


A PSTN line is a PSTN line and makes no distinction as to what it is being used for…you do that by publishing whatever number you want to do whichever function (fax or voice) you want so that callers will know which number to use for the desired function.

The issue is that you queried about it possibly interfering and the answer there is also a yes, it will interfere. A call is a call and if you elect to send a fax out of the 3rd line, then the line will be in use sending the fax and will therefor not process other inbound/outbound calls during this time, but the interference will be no different than if the line were handling a voice call…but…

You indicated that the lines 1, 2 and 3 are in a hunt group. This presents a problem as it may mean that if someone tries to send a fax to line 3 and line 3 is busy with a voice call, the inbound fax call may roll to line 1 or 2 instead. Additionally, when you fax out any PSTN line, the callerID will show the number of that line which may cause others to start using them for faxing should they take notice of same.

So if you assign FXS2 (fax) an extension number and then make an outbound rule that designates that FXS2 will only use FXO3, then all calls going from FXS2 will be delivered to the remote fax using the callerID of FXO3.

Finally, there is no fax detection at the analog trunk level. So, the question then becomes how will you be able to know if an incoming call is voice or fax and then route accordingly?

The bottom line is that you would be better off getting another line so that you avoid the issue of trying to co-mingle fax and voice calls. Also, as you are apparently using a fax machine, why not take the line directly to the fax

machine as sending it thru the PBX really adds no value and it also avoids the cost of an ATA.