I have a new 7400 running v4.51 with an SVMi20 that seems to be having trouble decoding DTMF. I can't replicate the problem, but the complaints are so widespread that it must be happening. With remote calls to the voicemail DID, it sometimes won't go to the mailbox when it's entered and will loop back to the general greeting. I've monitored port activity as I call in and it decodes and transfers just fine on every digit. I've done this from multiple phones and tried many mailboxes. Has anyone else encountered this elusive problem and is there an optimal DTMF timing adjustment that alleviates it? Thanks in advance!

Are the calls coming in remotley from a cell phone?

Are you using SIP trunks?

Calls could be coming from cell phones. I've tested repeatedly with my cell and it always transfers correctly. These are not SIP trunks. It's a standard 23 channel PRI. It always worked fine with the former OS500 R2 with an SVMi16. Yes, we learned the hard way about SIP trunks with IP phones and no in-call DTMF at all until the IP phone software was upgraded. This is something very different and extremely hard to replicate.

My personal experience with this has been that I have seen users with the slide phones or the qwerty phones that locks the key pad. It was on the call but the number buttons where not usable until they unlocked it. That caused the cell phone to not send the dtmf signal to the system. That is a long shot but with cell phones now a days, I honestly would not doubt if that was the issue.

I really appreciate your help, but I don't think I can point the finger just to cell phones. None of this happened before the system upgrade. People called into the old SVMi16 all the time and there was never an issue with dialing extensions. The PRI is unchanged and they still even have the same desk phones - Falcon 18-button. There has to be something different in the DTMF timing on the SVMi20. I guess the best thing to do would be to fire up the old SVMi16 and compare settings

Have the customer make a note of date and time and number called from then go into activity screen to get view what happened. Could the problem be with the PRI? Also, if you get a good tech at the NOC willing to work with you and explain the problem they may be able to make some adjustments.