Router, Line or the will of BT?

[#1]

Hmmm, seems no attachments for PM's
Grab from here
Zip file contains the exe file only, just replace the original. FYI the problem is that Routerstats has an extra space on the end of the Interfaces telnet command which this router does not like. Once removed everything worked as expected.
For the fluctuating SNRM values, I had the same problem. It seems it is related to a new connection (trying to outdo the exchange equipment). I found that turning off the router for at least 90 minutes then reconnecting cured it. SNRM has been flatlining since.
cheers
Graham

[#2]

Quote from: GrahamC

Hmmm, seems no attachments for PM's Grab from here Zip file contains the exe file only, just replace the original. FYI the problem is that Routerstats has an extra space on the end of the Interfaces telnet command which this router does not like. Once removed everything worked as expected. For the fluctuating SNRM values, I had the same problem. It seems it is related to a new connection (trying to outdo the exchange equipment). I found that turning off the router for at least 90 minutes then reconnecting cured it. SNRM has been flatlining since. cheers Graham

Works a treat, thank you :). However, the advice about turning off the router isn't particularly relevant to my connection as no other router has this problem. For example, using another router one minute after the X7N has no problems with fluctuating SNRM.

[#3]

Quote from: GrahamC

Zip file contains the exe file only, just replace the original. FYI the problem is that Routerstats has an extra space on the end of the Interfaces telnet command which this router does not like. Once removed everything worked as expected.

Have you reported that? My experience is that the author is very speedy about correcting bugs.

[#4]

Hi Gigagbit,
I was probably not too clear about the SNRM issue, it's a new connection with the router, not a new connection as in new installation. It may settle on it's own but I'm not that patient 
Anyhow, it resolved my problem. Maybe it's a quirk with the chipset itself.

[#5]

Hi Jelv
noted. Email with relevant info sent.
cheers
Graham

[#6]

Hi GrahamC, I hope you don't mind me re-opening this thread,
The Zoom X7N seems to have a few issues on my line, namely, when the SNRM drops at night from its target of 6dB to around 3dB, the connection stays connected, but come morning, the SNRM never goes back up to its original value. This does not happen to any other router I have tried/used. Any ideas?

[#7]

This maybe due to bits/tone allocations if some tones become unusable overnight. Try doing a comparison of a grab before the margin has dropped to one the following morning.

[#8]

Another possibility is that it's reporting the minimum margin seen during the current session - that might be useful as well as the current noise margin, but not instead of! Have you checked the manual?

[#9]

Quote from: Anotherone

This maybe due to bits/tone allocations if some tones become unusable overnight. Try doing a comparison of a grab before the margin has dropped to one the following morning.

That does happen, but it is only on this modem router that the margin doesn't recover. On other routers tones become unusable and "dissapear" (e.g. gaps in tone graph) but the margin still recovers.

[#10]

It might not always recover if the total number of bits available reduce below a certain point when too many tones become unusable, just worth checking out I thought. I'm assuming a re-sync restores the situation.

[#11]

Quote from: Anotherone

I'm assuming a re-sync restores the situation.

If by that you mean the SNRM goes back to its value of 6dB if I resync in daytime then you are correct.

[#12]

Hi Gigabit
Not had this problem myself, as the noise margin here only changes by +/- 0.1db from it's mean of 3.0 Downstream and 6.1 Upstream.
I must admit I do find some of the routers features, a little quirky/different from the norm, for instance setting the DNS within the router will not save unless I also provide a DNS for IPv6, which at this time I can't actually do. Still investigating this one 
I don't know if high bitwapping rates on my line is normal or a function of the router / MSAN / line characteristics, but viewing via RouterStats shows a count in excess of 275000 over the last 9 days. Looking at the bitloading graphs shows it is mainly a few frequencies being moved continually (offloading then reloading) but the Attainable (Max) Rate never changes. As the rates (Connection or Max) do not change there is no noticable performance issues and to be honest I would be non the wiser unless I reviewed the info in RouterStats.

Quote from: jelv

Another possibility is that it's reporting the minimum margin seen during the current session - that might be useful as well as the current noise margin, but not instead of! Have you checked the manual?

I don't think it's reporting "minimum" as I get a continual variation throughout the day. As far as the manual goes, let's just say it is minimalist 

[#13]

@Gigabit
I don't suppose that particular Zoom X7N of yours is faulty? Is the firmware version the same as Graham's? Would it be worth re-flashing just in case there's a gremlin there?

[#14]

Quote from: Anotherone

@Gigabit I don't suppose that particular Zoom X7N of yours is faulty? Is the firmware version the same as Graham's? Would it be worth re-flashing just in case there's a gremlin there?

Could be, although this is my second one of these (the first one had a problem with a wildly fluctuating SNRM margin). I don't know what version Graham is running. Graham, could you fill me in?

[#15]

I'm running the latest firmware
Zoom X7n v1.0.3-2
available @ http://www.zoomtel.com/techsupport/adsl/5790.shtml