[Ascend] RE: (ASCEND MAX 6000) Caller receives solid high-pitch tone
Dave Montgomery guido-at-ipa.net <mailto:guido%40ipa.net>
Thu, 12 Apr 2001 09:06:27 -0500
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Your problem is caused by a bug in the TAOS running on your max. If you go to diagnostics and enter the command "avm" (or "lanp modem" for those running TAOS 8+) you will see the Max's internal list of its modems broken down into several categories. The free list, busy list, and dead list are pretty self explanatory. The real interesting items are the suspect list and disabled list (or W195 list if running 8+).
The max keeps track of how many bad calls each modem receives and if it exceeds a certain threshold it puts the modem on the suspect list. Once on the suspect list the max will only use that modem after all others are taken. If it continues to take bad calls the modem will be moved to the disabled list (or W195 list). At this point the max absolutely will not use this modem under any circumstances until the entire modem card has been reset. Unfortunately, the max will not reset the modem card until every single user has disconnected from that card. At which point the max will automatically reset the modem card and put it back in service.
The end result of this #@%@^%ed up process is that if you have one single user still connected to a 16 port modem card that the max has decided to put on the W195 list, you will essentially be missing 15 modems, as the max will _not_ use them. On a fully loaded 6096 this means that you have 15 more incoming phone lines than modems. The max will still attempt to take these 15 calls by directing them to the HDLC drivers (same thing it uses for digital ISDN) since there are no modems available. Hence, your callers receive terrible high pitched digital tones instead of the warm and friendly modem tones they were expecting.
So, how do you fix it? For a temporary fix you can either manually kick off the users still connected to whichever card is on the 195 list or you can reset the max. For a permanent fix you can downgrade or upgrade your TAOS.
7.0.4 and 7.0.22 both work well for us. 9.0.X is supposed to fix this issue...but it still seems to occur, although not so often. Unfortunately, 9.0.X seems to have plenty of other bugs to make up for any fixes. We have worked extensively with Lucent's top tier techs and engineers and they knew even less about the problem than I did. They did provide a couple test releases based on TAOS 8 code but it was really nothing more than a nice gesture from a well intentioned, if rather incompetent staff.
A couple other items and then I'm back to the coal mines: You can use "fatal-history" from diagnostics to see when this problem occurs even after the fact. It will be listed as Warning: 195 blah blah blah... No one seems 100% sure of what constitutes a "bad" call. I believe that any call which the max receives but cannot complete is bad. Which means that a bad trunk on a T1 or an old lady repeatedly dialing your max instead of her daughter, will both tend to exacerbates this problem.
We have maxes in many different cities and have seen this problem occur on every combination of ESF/D4 and B8ZS/AMI. It occurs on both channelized T1's and ISDN PRI. We have 5 different Telco's which provide us access and it has occurred on equipment in each of the 5 Telco's regions.
Lucent is clueless. - Hope this helps. - Dave Montgomery
Comment from RDE : As we heard from internal staff, all experienced Ascend experts and Ascend developers have left the Ascend company before mid of 1999, when Lucent took over the Ascend plants in Jan. 1999.
Now the MAX 6000 is end of sales and nobody may expect any help from Lucent. As we have heard, there are no more people from the old Ascend team and all others have different jobs now or have been fired.
Tip : try the highest available TAOS for the MAX 6K.