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7800VDOX Manually limit sync speed?

Posted: Tue Sep 19, 2017 6:11 am
by mattspace
Hi,

Can someone tell me if the 7800VDOX has the ability to manually set an arbitrary fixed maximum sync speed (on ADSL2+), so that regardless of the S/N settings, or quality of the line / attainable rate, it will only sync at or below an arbitrary limit?

If it does, (where) is the setting available in the admin system?

Thanks,

Re: 7800VDOX Manually limit sync speed?

Posted: Tue Sep 19, 2017 9:16 am
by billion_fan
mattspace wrote:Hi,

Can someone tell me if the 7800VDOX has the ability to manually set an arbitrary fixed maximum sync speed (on ADSL2+), so that regardless of the S/N settings, or quality of the line / attainable rate, it will only sync at or below an arbitrary limit?

If it does, (where) is the setting available in the admin system?

Thanks,
No option, you can only tweak the SNR

Re: 7800VDOX Manually limit sync speed?

Posted: Wed Sep 20, 2017 4:33 am
by mattspace
billion_fan wrote:
No option, you can only tweak the SNR
Ahh ok, is it something that can be achieved by SSHing into the modem? I recall finding something about that from a while ago on a different model.

Or, is there a good way to put in a feature request?

The problem I have is that my ADSL line, while largely stable, low ping, and fast downloads with S/N set to 1, is highly variable in the reported Attainable Rate (anywhere from 9600 - 10200 over the course of a few days) - if the modem connects at a time of the day when it's running fast, and then the line speed drops, I'm seeing the router report a S/N of 0.6-0.8 at its worst, which as far as I know means more errors, and more chance of the modem letting go of the connection, and my ISP seeing frequent disconnects and stomping on me with a speed limiting profile, and the associated half hour in a Philippines call centre trying to get them to remove it.

If I understand rightly, upping my S/N will slow the modem, but is it still going to leave me subject to the line variability, where as the speed drops, my (now larger) overhead gets squelched, and my modem will still let go of the connection because it can't maintain that larger S/N?

What I know from experience, is that a S/N of 1, is really stable, really fast, and really low pings, IF the modem is only synced at ~9300 - then I see reported S/N of ~1.4 - >2 over the course of the day, and it can maintain connections for weeks on end.

Re: 7800VDOX Manually limit sync speed?

Posted: Wed Sep 20, 2017 9:11 am
by billion_fan
mattspace wrote:
billion_fan wrote:
No option, you can only tweak the SNR
Ahh ok, is it something that can be achieved by SSHing into the modem? I recall finding something about that from a while ago on a different model.

Or, is there a good way to put in a feature request?

The problem I have is that my ADSL line, while largely stable, low ping, and fast downloads with S/N set to 1, is highly variable in the reported Attainable Rate (anywhere from 9600 - 10200 over the course of a few days) - if the modem connects at a time of the day when it's running fast, and then the line speed drops, I'm seeing the router report a S/N of 0.6-0.8 at its worst, which as far as I know means more errors, and more chance of the modem letting go of the connection, and my ISP seeing frequent disconnects and stomping on me with a speed limiting profile, and the associated half hour in a Philippines call centre trying to get them to remove it.

If I understand rightly, upping my S/N will slow the modem, but is it still going to leave me subject to the line variability, where as the speed drops, my (now larger) overhead gets squelched, and my modem will still let go of the connection because it can't maintain that larger S/N?

What I know from experience, is that a S/N of 1, is really stable, really fast, and really low pings, IF the modem is only synced at ~9300 - then I see reported S/N of ~1.4 - >2 over the course of the day, and it can maintain connections for weeks on end.
The only option is higher SNR to slow down your speeds, you can't cap the speeds via telnet as far as I know. (so try a SNR of 1.5 to 2)