We have an Adix system that connects to another via an IPNet card - not sure if I'm using the right term, 4 channels via the network, in the db shown as Digital E&M Tie. When pressing 9 or a Line key calls route via those channels to a PRI in the ECS on the school campus. If the destination has a menu requiring DTMF digits, the Adix site can't successfully send digits. The initial call always completes successfully.

If the called destination prompts to press 1 and 1 is pressed from a digital phone, the result will be "11 is not a valid extension" - same with other digits. When listening - pressing a digit will result in a solid half second or so of the tone followed by the same DTMF tone maybe a quarter of second or less in duration.
It doesn't happen with local COs in the Adix. Doesn't happen if I manually dial an IPNet trunk followed by an access code of a local analog trunk in the ECS.
It's only when the call routes normally to an IPNet trunk to the ECS and goes out over the ECS's PRI. Supposedly back in January a reset of the ECS resolved the trouble - but I'm not so sure, it's just what I was told. Like in January, I reset the Adix and scheduled the ECS to reset that evening, same results. For now I asked the customer to use an access code for a local CO in the Adix when placing a call to the business with a menu.

I even went to another school several miles away to simulate the routing. Selected an IPNet trunk, then 9 + our office, the called party heard the double digits. That school and another typically route over their local COs so they don't have the trouble. At this point we're not sure what to try next. Maybe there was some kind of network QOS change?

Used to see this problem a lot on PRIs, but with SLT station dialing. The fix was to deny Dial-On-Conversation (Stations>SLT>Dial-On_Conversation). I haven't fooled with an IPNet trunk in over 10 years, but do seem to recall they acted as an analog-type of connection. Try setting ALL of your SLT ports to Deny for that setting. It's counter-intuitive, I know, but try it and see.

The only SLT ports aren't really SLTs, but Digital VMOP which go to the Esna voicemail in another building. The Dial On Conv. for those are set to Deny.

Thanks for the info though, was not aware of that setting. There's not a lot of phones on this Adix, classrooms and a couple offices including unfortunately the nurse's office - she routinely accesses a medical facility with a menu. The main office and I.T. office have 5910 ip phones off the main ECS in another nearby building, which don't have the trouble. For now, or for good we may need to give the nurse an IP phone, and use up one of the licenses in our pool.

You can make the same setting change for digital phones in Stations>Outdial (CO). Worth a try...you just need to set the change for ALL stations of the type IIRC

Oh yea - I do see digital stations have the parameter too. Yes worth a try, thanks.