Answering Machine beep causes Fax to start

[FordMan77]

CM 5.1.2.416.4 on S8730 Duplicated Servers w/ G650's and 2 PN's

Have a weird issue that I've never seen before and hoping someone can shed some light on. User at analog ext. calls outbound to her house (local call) and gets their answering machine. Leaves a message as normal. This machine plays some type of beep at the end when you complete the recording of a message, then for whatever reason you hear fax tone on the line.

It sounds to me like the beep the answering machine is using somehow triggers a fax on the PBX side, but I don't see how? I have had a user at a digital phone ext. try this same scenario, and it happens then as well so I know it's not just the analog ext.

Below is a trace that I pulled when this happens from the start of the call to the point where you hear the fax tone and the caller hangs up.

11:11:46 tone-receiver 01B0103 cid 0x3043
11:11:46 active station 5367 cid 0x3043
11:11:48 dial 9625 route:HNPA|ARS
11:11:48 term trunk-group 6 cid 0x3043
11:11:49 xoip: fax:Relay modemT tty:US 10.28.125.141:15120 (igc)



LIST TRACE

time data
11:11:49 xoip: fax:Relay modemT tty:US 10.28.125.142:44100 (igc)
11:11:49 G711MU ssff ps:20 rn:1/1 10.28.125.141:15120 10.28.125.142:44100
11:11:49 dial 9625XXXX route:HNPA|ARS
11:11:49 route-pattern 1 preference 1 cid 0x3043
11:11:49 seize trunk-group 6 member 3 cid 0x3043
11:11:49 Calling Number & Name NO-CPNumber NO-CPName
11:11:49 Proceed trunk-group 6 member 3 cid 0x3043
11:11:50 Alert trunk-group 6 member 3 cid 0x3043
VOIP data from: 10.28.125.141:15120
11:12:01 Jitter:0 0 0 0 0 0 0 0 0 0: Buff:11 WC:11 Avg:0
11:12:01 Pkloss:0 0 0 0 0 0 0 0 0 0: Oofo:0 WC:0 Avg:0
VOIP data from: 10.28.125.142:44100
11:12:03 Jitter:0 0 0 0 0 0 0 0 0 0: Buff:11 WC:10 Avg:0
11:12:03 Pkloss:0 0 0 0 0 0 0 0 0 0: Oofo:0 WC:0 Avg:0
11:12:08 active trunk-group 6 member 3 cid 0x3043
VOIP data from: 10.28.125.141:15120



LIST TRACE

time data
11:12:09 Jitter:0 0 0 0 0 0 0 0 0 0: Buff:11 WC:11 Avg:0
11:12:09 Pkloss:0 0 0 0 0 0 0 0 0 0: Oofo:0 WC:0 Avg:0
VOIP data from: 10.28.125.142:44100
11:12:09 Jitter:0 0 0 0 1 1 1 0 0 0: Buff:12 WC:10 Avg:0
11:12:09 Pkloss:0 0 0 0 0 0 0 0 0 0: Oofo:0 WC:0 Avg:0
11:12:12 Start Fax Relay aux:none tone:CED from voip: 10.28.125.142:44100
11:12:12 Start Fax Relay aux:none tone:none from voip: 10.28.125.141:15120
11:12:17 idle station 5367 cid 0x3043
11:12:38 TRACE COMPLETE station 5367 cid 0x0

 

[dufus2506]

I don't think that it's your system at all.

Ask the user if they have a combination fax/printer/scanner at their home. If so, have them check to make sure that the fax part isn't set to auto answer.



Carpe dialem! (Seize the line!)

 

[FordMan77]

If this users home is called from a cell phone, I'm told it does not occur.

The only thing that I can think of is that a fax machine/modem somewhere in the building is half-tapped onto the same wiring as that analog extension, and when it hears the beep it begins to attempt to talk to it as it normally would. Problem is, without being onsite there is no way to track this down, as it does not show on the trace.

 

[EPalle]

The only remark I can add, based on the provided trace, is that the codec (used in region 1) is Fax enabled.
And the tone generated by the users home voice mail system (at the end of the message) triggers this (don't know where the fax tone is coming from, if I'm honnest).

If you don't need that you can switch it off by changing the codec (ch ip-codec x; then 2nd page).
Or you can try it out and see if this helps or not.

But it sounds to me like the user's vm is causing the problem (as this only appears when he/she calls home), so not a PBX issue. But always good to look at...