sundance-communications.com/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems Random error tone when hook off phone to call (Only analog phones)

I have a problem in a OS7400 (2 cabinets).
This client only have analog trunks connected to the PBX, and when a analog phone is hooked off to make a call, is heard an error tone randomly for 2 seconds rather than the regular dial tone, then is heard the regular dial tone, but no matter what you dial the phone doesn't response, this occurs only in the 200 analog phones (Not in the digital phones) and randomly.
If you try to hook off a phone to make a call at least for 10 times, it doesn't work until finally regular dial tone is heared and the phone can make internal or external calls.
This ONLY HAPPEN when too many calls are coming and going out from/to the PBX (Most commonly in mondays, tuesdays, days after holyday, BUT ONLY in rush hours).

MP40: 4.53C
Both LP40: 1.27

DB attached (.rar without password, DB without password):
https://www.mediafire.com/?mmw4czk2h49plwl

This is probably due to lack of DMTF receivers.
These are provided by either a CRM or MFM daughter card which sit on the LP40 card.
The OS7400 has 16 DTMF Receivers per LP40 card.
You can check the status in IT Tool, in the download you have attached all 16 are in use, so until 1 of these becomes free you won't be able to dial out from any analog device (phone, fax, etc)

When an Analog phone goes off hook the system assigns a dtmf receiver to it.
If there are none left then the phone won't break dial tone.
Which sounds like the issue you are having, especially since it mainly happens during busy time.

Great! I'll test it!
I guess that this is the problem, because de 16 DTMF all are used almost all the time.

I've added 2 CRM boards to the PBX, issue solved.
Thanks!