Tips/Tweaks to improve an unstable connection

Hello all, I'm new to the forum and new to problematic dsl connections but hopefully someone can help!;

Last year BT installed 2 phone/broadband connections for a remote site we operate from. One dsl connection runs a zyxtel modem with a fixed ip address for security cameras and as far as I know is 100% rock solid. The second line is connected to a 2-wire HGV2700 with a Cisco router connected to the 2-Wire to allow us VPN access to our internal network.

Unfortunately the connection drops out frequently bringing the VPN tunnel down with it. To reconnect we have to cut the power on the 2-wire and let it reboot. When connected again it could stay up for a day or cut out again after a few minutes: completely random.

BT have tested the line, engineers have checked and rechecked connections and as far as they are concerned everything is ok. I've replaced the 2-Wire twice and still have a problem. Two weeks ago I replaced the modem cable and the connection was (nearly) perfect for a week. Now it drops out repeatedly again.

Its a long line, 8km, and as such BT can't promise fast speeds which is fair enough but I need the connection, albeit slow, to be reliable as we have users who print remotely to the printer behind the VPN tunnel.
Unfortunately I can't post signal strength stats today but will get up to the site tomorrow and find out.

Is there anything I can do to try and improve the connection to make it more reliable?

Thanks
Niall

An 8kmline is quite likely to be a bit temperamental.

Getting the stats is certainly the place to start. Ensuring that there are no phone extensions at all on the line and keeping the router close to the socket on a short lead (maybe screened but I'm not convinced that this isn't a catchpenny that does nothing) is about all that can be done your end though apart from trying to keep other electrical gear to a minimum (especially anything with motors which could generate sparks).

Have you optimized internal wiring see link here.

Also stats wud help, as mentioned, would really need to know what modulation your line is running on if you could? For instance if it is running on adsl2+ that could be causing or contributing to the disconnects as on longer lines (mines nearly 5km) it makes it more unstable, changing the modulation to adsl2 helped on mine, but would need to know particulars about your line.

put a zyxel on the wobbly line ?

Thanks for the info guys, here's the stats from the 2-wire as of this morning

Rate 512 U / 352 D
Max Rate 512 / 372
Noise 6 / 3
Att 63 / 31.5
Output Power 15.7 / 12.9

Protocol is G.DMT Annex A
Channel = Interleaved

When I plug in to the master socked with phone/fax disconnected, the Rate and Max Rate on the downstream change to 416kbs and the noise ratio on the upstream increases to 4db

I considered ditching the 2-wire in favour of another modem but will it make any difference or are there some modems that can maintain a better connection?

If the other line is more stable why not swap your important connection over to that and run the security camera on the unstable one.

Regarding router/modems - in general the 2wire is well regarded. On my old line (not a long one) I found that a Speedtouch 585v6 outperformed one. What you do need to avoid is anything with a Texas Instruments AR7 chipset. IMO Broadcom based units perform best.

As mentioned above make sure there is no ring wire. A filtered faceplate would be a good investment.

The dodgy line is only really for PC connection to stock control system but the security cameras is the most important connection unfortunately!

The filtered faceplate does seem worth getting but I wanted to avoid throwing more and more cash at the problem when it might be BT's fault all along.

I'm not sure if this is standard practice but when installing the second line, BT tapped off a pair from the main trunking that is terminated at good connection master socket and joined it with a bit of Cat5e cable we had running under the floor. This is then terminated at the master socket of the dodgy connection. The only differences between good and bad lines is the Cat5e extension on bad line, zxyel modem and fixed ip on good line. Phone and fax are also connected to dodgy line with filters attached.

I'd like to move the master socket of the dodgy line beside the good line but I just found out that this is BT's property and can't be touched

More faults are caused by dodgy internal wiring than by faults on the BT cabling.

A filtered faceplate can be had for ~ £12 and may (or of course may not) fix it - I wouldn't consider £12 tp be throwing money at the problem.

Using Cat5 to extend the BT pair is non standard but so long as the other pairs in the cat5 cable remain unused I doubt it would cause any problem. From your description the most likely cause of problems is the phone/fax. Is that on a filter that connects directly to the master? Unfiltered plug in extensions can introduce noise through their inbuilt ring wires. You should never run a router on one.

I've just ordered the filtered faceplate so hopefully it'll show some improvement. Your right though it is a small price to pay; I'd wanted to avoid buying a new modem and replacing all the cabling

I have a filter plugged into the master, with the modem and another filter. The phone and fax are both plugged into the second filter; its a bit of an untidy job but I hope thats not causing any problems?

So long as the filter is halfway decent what you do on the voice side of it can't have much impact as any noise pickup there has to go back through the filter so it will be highly attenuated.

It may just be that your second line simply isn't as good as the first so whatever you do may not improve things. Comparing stats with the router into the inner "test" socket and nothing else in the filter with what you get with your normal setup will tell you if there is extra noise (so lower sync) with the phone and fax connected.

If nothing else the filtered faceplate will be a lot tidier.

Edited by kwikbreaks (Fri 19-Mar-10 13:39:56)