Showing results for 
Search instead for 
Did you mean: 

AudioCodes 1248/124 working with Emergency Blue Lights and All Campus Alert


We have ATAs by AudioCodes. We have both 1248 and 124 units. We are having issues with DTMF working with the Emergency Blue Lights and our All Campus Alert System. We can connect with each of the units but once connected they do not seem to pass DTMF correctly. Any help would be great. 


Community Champion | Zoom Partner
Community Champion | Zoom Partner

hi gs283260,


according to the zoom certified audiocodes ata as of 8/23/2023, I do not see 1248 or 124 as being certified by zoom.  Note that mp-124e is certified.



  • For setup instructions, see the provisioning guide for AudioCodes MP series gateways.
  • Some models with certain revision numbers are not supported. Refer to the AudioCodes website for more information.
  • For assisting provisioning on the MP504/508 (formally M500Li) Analog Gateway, follow these instructions.
  • When you enabled SRTP for these models, there is a reduction in the available channels. Only the following channels have SRTP enabled and are available for use:

    • MP-124 - 17 channels from 24
    • MP-118 - 6 channels from 8
    • MP-114 - 3 channels from 4
    • MP-1288:
      • For the new hardware component, please downgrade the firmware to version 7.40A.250.851. The upcoming new firmware 7.40.500 version, due end of May 2023, will support the new hardware component blade. You can review the AudioCodes product notice #0491 component replacement for detailed information about new hardware revision.
      • For existing hardware, continue to use the current published firmware version. 
    • (MP-1288, MP-112, and MP504/508 (formally M500Li) don't have a reduction in available channels)


please also see:

Setting Up AudioCodes MediaPack ATAs for Zoom


Did my response answer your question? If so, please don't forget to mark the reply as an accepted solution.


thanks,  eliot


Eliot, thanks for this,  but we already have this and these units are already working with Zoom. We are having issues with the Blue Lights not working with the units with the DTMF.

Community Champion | Customer
Community Champion | Customer

Hello @gs283260 ,


Very familiar with the MANY issues surrounding DTMF while using Zoom and AudioCodes ATA's.


Have several MP-1288s deployed in multiple datacenters across a large university campus, support an on-site PSAP along with hundreds of Blue-Light Phones, Intrusion Alarms, Fire Alarms, Access/Gate Panels etc.


Have clearly shown over 100's of hours of testing between Zoom and AudioCodes (Engineering and R&D) over MANY months; DTMF is basically non-operational when trying to pass it through Zoom. Apparently this issue stems from how Zoom has chosen to implement things like RFC2833, G.711 and OPUS 


This is a known issue that is not getting enough attention!! *cough* Zoom Phone Engineering *cough*


The only fix that we have found is to completely bypass Zoom for any equipment that needs to send DTMF. We have had to implement intra-ATA routing between our MP-1288s. This adds further headaches in administration not to mention we have hundreds of CAP licences that are useless.


On-prem analog infrastructure is a key component to a large organization moving to a new phone system; and it is critically important as it supports services like 911 and Fire Alarms.


What is truly disheartening is that Zoom seems to consider on-prem analog infrastructure a small and insignificant portion of their Zoom Phone product to apply the needed engineering cycles to actually fix this problem. I won't even start to get into the hot mess that is managing a AudioCodes MP-1288 and Zoom.


I know many folks who work at Zoom and honestly think Zoom is a great partner despite this issue. Zoom Phone is an excellent VoIP solution that really elevates Zoom to a World-class UCaaS platform; but the fact that large on-prem analog issues can't be addressed, leaves me scratching my head.


If you or anyone else on this forum ever wants more details about what we have had to do to get DTMF functioning, Send me a DM and I would be happy to meet or take a call.


Hope this is helpful


Hi All


Was this issue ever resolved?  We have identical problems with our blue light phones (Ramtel) using Zoom via Audiocodes.

Community Champion | Customer
Community Champion | Customer

Hello @cdmiller ,


We are decommissioning all of our AudioCodes MP1288s in favor of the Grandstream GXW4248V2.


By moving to Grandstream we have solved all issues related to DTMF as well as hardware problems that seem endemic to the MP1288s.


Hope this helps


Thanks so much for the information.  I'll look into it.