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Sync Issues

N/A

Sync Issues

Ok i have had sync issues since dslmax.
I was upgraded with no warning and no notification.

about 6 months later the problem still exists.

Since dslmax actually came into play i moved jobs. Now guess what i work for an isp. I have requested the plusnet change the snr to 15db. Which should be simple to make so simple i have actually made this request though BT for our end users.

Plusnet for some reson is unable to complete this simple request.

Example of disconnects

Dec 6 08:20:18 router 798: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 6 08:20:33 router 804: %LINK-3-UPDOWN: Interface ATM0, changed state to up
Dec 6 09:25:38 router 812: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 6 09:25:54 router 818: %LINK-3-UPDOWN: Interface ATM0, changed state to up
Dec 6 10:20:18 router 838: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 6 10:20:35 router 844: %LINK-3-UPDOWN: Interface ATM0, changed state to up
Dec 6 10:28:29 router 852: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 6 10:28:45 router 858: %LINK-3-UPDOWN: Interface ATM0, changed state to up
Dec 6 16:21:54 router 950: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 6 16:22:10 router 960: %LINK-3-UPDOWN: Interface ATM0, changed state to up
Dec 6 16:54:52 router 977: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 6 16:55:07 router 983: %LINK-3-UPDOWN: Interface ATM0, changed state to up
Dec 6 16:57:54 router 991: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 6 16:58:11 router 997: %LINK-3-UPDOWN: Interface ATM0, changed state to up
Dec 6 18:19:08 router 1022: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 6 18:19:23 router 1028: %LINK-3-UPDOWN: Interface ATM0, changed state to up
3 REPLIES
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: 04-04-2007

Sync Issues

Hi,

There shouldn't be any problem doing this, however it needs to go through our faults process so that it can be correctly tested and raised in case there's something else that's causing it. I've raised 4 exactly the same type of faults myself in the past month or so (fine before max, but random drops of sync after), 3 were simple "up the target SNR and it fixed it", but the 4th needed an engineer visit as there was something wrong with the line.

If you can go to

http://faults.plus.net

and complete all the questions, it'll run the automated tests and we can get this done for you.
N/A

Been There

Already been down that route.

They would send a BT engineer out. Get another engineer at the other end of the line. Plug in something that is like a fluke tester to messure noise and go. This is within our limits.

The part that the support staff are not understanding is. The SNR will go up and down more than the minimum that is required to sync.

eg line sync @ 5.2mbit with 8db.
The line then drops to 0db
It resync at 4.9mbit at 8db.

Then the SNR drops to 0 again. But when it resyncs the noise can be reduced again causing it to sync @ 5.2mbit and it repeats in this endless loop. Thus increasing the minimum SNR to 15 sorts the problem.

at BT engineer will never see this problem because they only monitor it for a few minutes. For them to see this properly they would need to monitor it for 3 hours late on in the evening.

Trying to explain this to support staff or to non technical people can be a waste of time.

Unfortunatly for me i used to be part of a team building modem's (much more advanced than xDSL) and understand how they work. Getting somebody else to fix something in a modern telecom company seems impossible.

PS. I am not ranting at plusnet support staff. I am ranting at 95% of the industry as a whole. Cause no matter who i go to i will end up with the same crap.
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: 04-04-2007

Sync Issues

It totally makes sense, and if the CSC aren't clear on it then I'll be sure to rebrief them. Generally though we don't get requests that are just "please increase the target SNR" we'll get a fault ticket reporting an intermittant sync fault and result will be raising a fault to BT who then increase the target SNR.

If your line doesn't get done then let me know and I'll get the SNR upped for you.