Router lockup

pauljordan

I experience daily line drops from my ISP (Vodafone). The result of which makes my router lockup. The only way out of the situation is to switch the power off then on again on the router. I have swapped the router with 3 others, one BT Voyager 210, Negear DG834 and ZyXEL 660. I get the same lockup problem with the Voyager and Netgear but not the ZyXEL . The ZyXEL is a very poor modem/router and do not wish continuing using it. I wonder though why does the Voyager and Netgear bomb out? My line stats are as follows......

Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 00:02:38:01
Line Coding Trellis On Line Up Count 1

Statistics Downstream Upstream
Line Rate 3072 Kbps 384 Kbps
Noise Margin 6.0 dB 12.0 dB
Line Attenuation 48.0 dB 26.0 dB
Output Power 0.2 dBm 10.7 dBm
K (number of bytes in DMT frame) 97 13
R (number of check bytes in RS code word) 12 12
S (RS code word size in DMT frame) 1 4
D (interleaver depth) 32 8
Super Frames 557726 557729
Super Frame Errors 3194 0
RS Words 37925398 9481393
RS Correctable Errors 672591 0
RS Uncorrectable Errors 8330 0
HEC Errors 1365 0
OCD Errors 0 0
LCD Errors 0 0
ES Errors 0 0



Anyone any ideas what the problem could be?

Sponge Bob

The margin is crap @6db, bare minimum. This is expected on large exchanges which are LLU but not smaller ones out the country for complex reasons that would bore you.

The attenuation indicates a longish line ....were it lower then we could say it was the router. Neverthless the margin should be over 10db at that attenuation.

1. Try the router with no filter on the line, straight into the socket as the filter could be faulty. Does the margin improve ???

2. If no then the line cannot handle 3mbit which is the minimum voda package. Ask them to 'profile' or 'throttle' it to 2mbit and see if that margin improves which is key.

pauljordan

Thanks Sponge Bob.....

I plugged the ZyXEL router into the same line and filter and I have a downstream noise margin of 20dB. Would that indicate a bad Netgear and Voyager router? They are fairly old ones.

Should I buy a new modem/router as I need to have remote access to the modem via dyndns. The ZyXEL for some reason won't renew its WAN IP on line drops....

old_aussie

Try updating the firmware on the older routers

pauljordan

old_aussie wrote: »

Try updating the firmware on the older routers

Thanks old_aussie, but I did that before testing and got same result.

Sponge Bob

What happens with no filter in that socket.

pauljordan

With the ZyXEL router it goes from 20dB with the filter to 15dB without. On the Voyager it goes from 12.5dB with and 12.4dB without.

Seamingly the noise margin has changed since yesterday on the line. But with the Voyager it makes little difference with or without the filter....

Sponge Bob

A bit all over the place that, a margin of 10db or higher should be stable.

1. Are you testing with the main socket only ??

2. Can you disconnect the wiring 'inside' the main socket in case there is a short in there.

3. If there is no 'main' socket per schematic below ( it has a TE or Eircom logo on it ) I think the internal wiring is likely dodgy .. How old is the gaff/wiring ?

Schematic

http://www.reci.ie/Portals/0/RECIDocuments/technicalinfo/eircominterface.pdf

pauljordan

I checked the wiring in the main socket and it all looks good. The telephone supply is via an outrside overhead cable.

I have isolated all the other extension lines going to various other locations in the house. I have been monitoring the noise margin over the last couple of days and it changes greatly over the day. Noise margin can be anywhere between 6 - 10dB with the BT modem.

If I take a reading with the BT modem and it reads 8dB and then I plug in the ZyXEL it would read 14dB. There is inconsistency between the two modems. The ZyXEL doesn't really drop much.

Dare I say I never had a problem when it was a BT line with exactly the same setup!! The Vodafone service drops the line every 24 hours on the nose. e.g. last few days line dropped at 11.34am then today same thing.

Irish Steve

Dropping daily sounds like the standard router setting that is used by most ISP's. it can be changed in some routers to be less, and sometimes more. it may be worth having a go at the advance options in the router, and set the lease time under the DHCP setting to a longer period, and see if that makes any difference. I've seen differing reports on how this setting is used in different places, so I don't want to be dogmatic about the difference this might make.

No harm in trying this, it might help

Steve