A knowledge confirmation/correction please

I may have to have another argument with my ISP in the new year. At present my modem is connected in excess of 70Mb/s (71Mb/s I think but I'm not at home to check) with a similarly high profile. I've used Bald_Eagle's tool to download some graphs and they show little to no variation in the bits per tone or SNR over the course of half an hour.

Would I be correct in saying that the cause of my current 30Mb/s throughput cap cannot be interference? My understanding is that the connection speed is (give or take TCP overheads) what the line is capable of and if there was interference my modem would be connected at around 31Mb/s?

FYI here's one of the graphs I got from my modem:

Link Removed. sadoldman

This is the same fault I've mentioned previously - it repeats on the 19th of every other month (June, August, October and now December) and takes a few days to clear - or at least a few days after it starts a modem switch off for 20 minutes fixes it.

The most annoying thing about this is Tech Support's insistence that it's interference and the only thing they can do is send an engineer round to check my line. They are reluctant to do that (so am I) as the line test shows as all clear (quelle surprise). At that point they tell me I'll have to live with it and that pretty much ends the conversation.

Edited by Sadoldman (Wed 26-Dec-12 06:51:56)

It might be useful if we could have the modem stats, (both --pbParams and --show, or even --stats instead of --show as that gives the error stats), for when it is bad, for comparison. That might help analyse things a little better.

I remember reading your earlier post about the exact 2-monthly occurrences. I've no brainwaves at the moment I'm afraid .

your line has similiar attenuation to mine and similiar attainable figures, you seem to have also similiar noise levels to me but yours is a bit higher.

sadly tho if you are having issues on the 19th you need to run your ongoing graph around that time period so we need to wait a few weeks probably.

Edited by Chrysalis (Wed 26-Dec-12 03:47:56)

Link remove because of some inappropriate images.

This may explain it.

In reply to a post by Chrysalis:

your line has similiar attenuation to mine and similiar attainable figures, you seem to have also similiar noise levels to me but yours is a bit higher.

sadly tho if you are having issues on the 19th you need to run your ongoing graph around that time period so we need to wait a few weeks probably.

I'm hoping and expecting that when I get home on Friday I can restore normality. That appears to be the case on prior occasions.

* In June I just gave up after a couple of days and after 10 days (hmmm...) it fixed itself.
* In August rebooting on the 22nd seemed to fix it.
* In October I was away until the 24th and rebooting it then fixed it.

Given some of the curious dates (3 days after my install went live, seems to go on for three days, once cleared after ten days) my current theory is that my regrade from 40/10 to 80/20 was botched and the old 40/10 profile is still around and for some reason every two months it goes through a 'retraining' period. The speeds I get albeit highly variable are about what I'd expect from a 40/10 connection.

All of this to my mind counts against it being interference. I don't reboot the modem - I just reboot the router to establish a new session. This time I will first tell the router to disconnect (which hopefully terminates the current PPP session so I don't have to wait 20 minutes).

Edited by Andrue (Wed 26-Dec-12 11:22:10)

In reply to a post by Sadoldman:

Link remove because of some inappropriate images.

This may explain it.

Perhaps if this forum was updated, then we'd be able to post pictures directly, it really is in need of a refresh, I mean I'm viewing this on a 27" monitor but most of the screen is black background with a tiny window of the website in the middle!

http://i672.photobucket.com/albums/vv87/Ronskiman/Va...

Edited by R0NSKI (Wed 26-Dec-12 10:33:28)

How about:

http://i48.tinypic.com/15hd2xj.png

I don't reboot the modem - I just reboot the router to establish a new session.

Presumably that means that you are not affecting anything to do with the physical or DSL layers, as the modem will stay connected and synced. This confirms your position that it isn't a "line" issue as all a new PPP session will do is send the prevailing sync speed up the food chain as refreshed data.

In reply to a post by R0NSKI:

Perhaps if this forum was updated, then we'd be able to post pictures directly, it really is in need of a refresh,...........

I think Seb is well aware that some updating would help but as the staff who provide and run the site all have to earn a living with day jobs, time and money do constrict things.

Both mods do it because they believe that a site that is truly independent even if a little old fashioned is worth the effort. The basic aim of providing impartial information and being able to use the resources of members only too willing to help others remains. regardless of the format.

We mods of course get our reward with the love, respect, and admiration of every one of our members.

sorry I meant your interference is similiar, I wasnt necessarily saying it is interference.

Cant say anything at all really as need to see the sync behaviour around that time. If the sync doesnt change at all then it points to what you suspect.