System: SV8100
At my main site, I have a PRI and I can dial 9,511 or 9,611 just fine. I can also call either 9,911 or 911 just fine. Everything normal here.
The problem is at my branch offices where they have CO/POTS trunk lines.
When they dial 911, or 9,911, or 9,511 or 9,611 type numbers, they get rapid busy 5 seconds after dialing the last digit.
They are not using ARS.
However, the calls goes through fine if I terminate all of them with a # - For example, 9,611# works fine.
Its like the system is waiting for more digits to be entered.
This issue was discovered because they needed to call 911, but office staff were met with rapid busy after dialing 911 or 9,911; but police officers came onsite reporting a bunch of ring/hangups.
I have worked with my local NEC authorized dealer, and they have not had any luck figuring the issue out.
A work-around that I discovered works is changing 21-01-03 "External Call Inter-digit Time" from the default of 5 to a value of 0.
This allows the calls to go out, without the system dropping the call 5 seconds after the last digit is entered.
Big kudos to anyone who can figure this one out!!!