ARS Intermittent dialling problem with embedded LS / GS trunk

[Jakt99]

Hi All

Got a strange one. Not sure if its HW or SW issue.
Thru ARS calls intermittently fail to any number (To land lines or cell/mobile). Demonstrated by dialled the same number consecutively and 3 of 5 calls fail..Doesn't matter if you hand dial or use last number redial key.

Call failure is noted by by message from telco stating "the call can't be connected"

I use the individual trunk access feature and dial same number without a hitch / 100 success rate. Or using butt on pstn line.

ARS config
- leading digit zero (with 2nd dial tone)
- digits dialled, cover local / national numbers, digits to follow definted to exact number scheme and all sent to routes.
- all routes assign have same trunk group containing 3 pstn lines) with COR defined for local service, overlap at default 4
and point to digit mod table 2 (absord 1)
- No tone plans in digit mod table.

Circuit descriptor (default settings as I alwas use)

All lines are clear of noise.

I can only think that something going one with digit absorb not working right, hence decided to upgrade sw from mcd 4.2 to 4.2 sp2 and isuues unchanged.

??????

System
CX II MCD 4.2 and MCD 4.2 SP2

 

[MitelInMyBlood]

I would never-ever upgrade the system software unless told to by Product Support. This is a shotgun approach and risks breaking other things that weren't broken. Secondly, always download and read the Release Notes with a new load. This document tells you what's fixed (and what isn't) - if you don't see your specific issue mentioned, then the new load won't address it.

By virtue of the results of your other tests (direct trunk select + testing with the Butt set) you've eliminated the telco line as the possible problem. What's left is the timing parameters in your trunk circuit assignment.

Depending on your telco, not all PSTN trunks return dial tone as quickly as others, so possibly your system is sending the digits to the trunk before the trunk is ready to accept them. Try making a call progress tone plan that waits for dial tone before outpilsing the digits on the trunk. You can also create a call progress tone plan to momentarily stall digit outpulsing. For example, set the tone plan to look for something it will never see, such as NA Specialized Carrier Tone, then set the time to wait for tone to something like 2 seconds, then set action to take on timeout to outpulse DTMF. We've had to do that in rural areas where we sometimes have to deal with "Lum 'N Abner's Telephone Company" (Bait & Boats Rented)

Original MUG/NAMU Charter Member

 

[kwbMitel]

I Always ALWAYS! insert a 1 second pause before dialing on analog trunks. Create a tone plan to wait for dial tone 1 sec.

The Digit Mod table would insert <T01> to use tone plan 1 for example.

Your issue is cause by the system dialing before dial tone is present.

**********************************************
What's most important is that you realise ... There is no spoon.

 

[Jakt99]

Thanks again chaps for advice

Issues rsolved, I setup a tone plan marker as suggested (detected US precise dial tone, we are in Australia)and applied to the digit mod plan. I also needed to tweek the digits dialed assignment. All analysed digit lengths had to be set to unknown length otherwise dialling still failed but less frequently.

In regard to upgrade, yes totally agree not to do, unless reading release notes etc. This wasn't a knee jerk type reaction. In this instance we have deployed mcd sp2 to several sites over the last month of similar site config so was fairly confident that wasn't going to introduce further issues.

Also spoke with an associate who appearently experienced same problem with mcd 4.2 a while back and he resolved by downgrading to 4.1 and issue dissappeared.