Paging Echo

[chris.eakland]

Enviroment variables:
3cx 10 SP6
3cx running on dedicated HP Z200 workstation intel i5, 4GB RAM (over kill i know)
~55 phones mixed Cisco SPA504 / SPA525G2
2 CyberData Paging Amplifers
3 different page groups (building 1 only, building2 only, both buildings)

Issue:
When a user calls the page group and makes an annoucement, doesnt matter which of the 3 paging group, occiasionally it will echo/repeat itself 3 times. it sounds like a dubstep remix of the page... its rare, but happens about once every 30 pages or so. its been happening since installation and while the users find it funny, it should not be happening. phone call quality is fine, no echo or issues with inbound or outbound calls. its only when paging. nothing shows up in the server log in 3cx after the echo. tthe echo is happening on both phones as well as on the overhead paging devices. Google search results are all about echo calls for inbound/outbound calls but nothing about paging. has anyone else expirenced this? anything to check or test?

 

[craigreilly]

can any of your devices do multicast paging?

 

[chris.eakland]

Both overhead paging devices support Multicasting but are currently disabled. none of the paging groups use multicasting.

 

[paul1]

It could be that the paging speakers are being heard by the paging microphone in "echo" pages. I have worked with a device that buffers the audio of the page then sends it to the speakers a few seconds later. Here is a document on the one I worked with.

http://www.valcom.com/pdf/v9962.pdf

 

[chris.eakland]

That was my initial thought when i heard it first but the person who does the majority of the paging (receptionist) is by herself away from the paging devices and other phones.

 

[chris.eakland]

i happened to be on site when a page echo'ed here is the info from the 3cx log.
Extension 100 is the one who called the Page group 201

09:58:20.856 Currently active calls - 3: [233,264,326]
09:58:15.834 [CM503008]: Call(318): Call is terminated
09:58:15.831 [CM503008]: Call(323): Call is terminated
09:58:15.828 [CM503008]: Call(324): Call is terminated
09:58:15.824 [CM503008]: Call(317): Call is terminated
09:58:15.820 [CM503008]: Call(320): Call is terminated
09:58:15.818 [CM503008]: Call(325): Call is terminated
09:58:15.663 [CM503008]: Call(322): Call is terminated
09:58:15.658 [CM503008]: Call(313): Call is terminated
09:58:15.652 [CM503008]: Call(312): Call is terminated
09:58:15.644 [CM503008]: Call(311): Call is terminated
09:58:15.638 [CM503008]: Call(310): Call is terminated
09:58:15.443 [CM503003]: Call(321): Call to sip:[email protected] has failed; Cause: 487 Request Cancelled; from IP:192.168.1.138:5060
09:58:15.189 [CM503008]: Call(319): Call is terminated
09:58:15.187 [CM503008]: Call(316): Call is terminated
09:58:15.185 [CM503008]: Call(308): Call is terminated
09:58:15.183 [CM503008]: Call(307): Call is terminated
09:58:15.181 [CM503008]: Call(309): Call is terminated
09:58:15.179 [CM503008]: Call(298): Call is terminated
09:58:15.177 [CM503008]: Call(299): Call is terminated
09:58:15.175 [CM503008]: Call(300): Call is terminated
09:58:15.173 [CM503008]: Call(304): Call is terminated
09:58:15.170 [CM503008]: Call(306): Call is terminated
09:58:15.167 [CM503008]: Call(302): Call is terminated
09:58:15.163 [CM503008]: Call(303): Call is terminated
09:58:15.160 [CM503008]: Call(305): Call is terminated
09:58:15.150 [CM503008]: Call(321): Call is terminated
09:58:14.874 [CM503008]: Call(297): Call is terminated
09:58:13.221 [MS211000] C:326.1: 192.168.1.81:16408 is delivering DTMF using RTP payload (RFC2833). In-Band DTMF tone detection is disabled for this call segment.
09:58:08.985 [CM503008]: Call(301): Call is terminated
09:58:08.846 [CM503008]: Call(315): Call is terminated
09:58:04.607 [CM503007]: Call(297): Device joined: sip:[email protected]:40300;rinstance=d9538c3135f4508e
09:58:04.605 [CM503007]: Call(297): Device joined: sip:[email protected]:5060




i'm wondering if that message about 1.81 is delivering DTMF using RTP payload has anything to do with it.

 

[gschwab]

i'm wondering if that message about 1.81 is delivering DTMF using RTP payload has anything to do with it.

I don't think so, only thing I can think of is the possibility that one of the phones in the ring group might just by coincidence be in a particular state when the page comes through say handset was just picked up to make a call, off hook, on speaker etc..., really just guessing though. I would start by looking at all three groups for phones that can "hear" the overhead paging. could take some time but I still suspect that something is "hearing" the page and feeding it back. Again just a guess :?:

 

[lneblett]

A guess, but could it be that some phones have more than one account registered and as a result the timing is slightly off between the time the first account is hit and responds versus that of the second or third or ........however many other accounts could be registered to same?

 

[chris.eakland]

A guess, but could it be that some phones have more than one account registered and as a result the timing is slightly off between the time the first account is hit and responds versus that of the second or third or ........however many other accounts could be registered to same?

all phones are provisioned through 3cx and only have 1 account registered per phone...



the one thing that I noticed, that unlike a microphone too close to a speaker feedback which increases in frequency as it echos, when the page echos the message repeats it self 3 times starting about 1/2 way through the initial sentence, but its layered, like there are 3 of her singing in round.


John Smith, you have a call on Park 1.
..................John Smith, you have a call on Park 1.
....................................John Smith, you have a call on Park 1.


so by the time you hear "park 1" the first time, you've heard "john smith" 3 times. and it ends after all 3 rounds have been heard

 

[lneblett]

The echo, is it with the phones, the Cyberdata stuff or both?

 

[chris.eakland]

both, phones and the overheads.

 

[gschwab]

Don't know if it's possible but maybe a phone in the group just happens to be set to forward it's calls back to the set that originates the page or something along those lines or the system is somehow triggering all three page groups at the same time? Maybe a wireshark capture would shed some light on it but that would take some time and a good bit of testing to duplicate the problem.
I think I would start by eliminating 2 of the groups and just do a single "both buildings" group and see if it changes anything, might at least rule out one possibility. :?:
Intermittent issues can really be difficult to solve.