I found that they do a considerably better job of maintaining a decent connection where the line quality isn't ideal. I had tried various of the consumer type products (Netgear, D-Link, even Linksys) and all were unstable in terms of the DSL implementations.
All of that's before the other benefits of being able to use IOS.
It may be or it may not be, It can also be that the router is not reporting stats correctly.
I tried several of these consumer grade products and found them to be pretty useless. OTOH I do have a high line loss to contend with. Usually, despite promises of updateability, there is one, perhaps, and then the product is end of life.
Not necessary. There is a quite respectable config generator application that will do it including the security settings.
Ive had a look see.
837 is pretty much similar to the kit I have now..ebay price sort of 55 quid upwards..Can you dictate what speed it trains at? or set a noise margin?
IOS is no big deal - its all in the brain somewhere..
One thing - it is only rated +40C..my equipment cabinet..let's say if I shut the door the D-link dies on a hot day and so does the print server ;-)
Yes. but it makes no difference.
I even pulled the PABX out and no change.
Don't think its that.
Ok..that makes sense. MMm. we have a lot of radio transmitters round here. Taxis police, emergency service etc.. I get bad glitches on my toy planes on some days - never on others..I wonder..however... in the end the real question is why the router/DSLAM are training at a abysmal SNR. The rate should be less to give more margin for error.
it is
It is
Place the modem at the filter and run
It is. Or rather its a modem/router. Plugged right into the socket.
>The Natural Philosopher wrote in news: snipped-for-privacy@damia.uk.clara.net:
I agree.
Elsewhere, you said you have the DSL-504 (and the example output cut/pasted from the Line Condition screen confirms this, as opposed to any similarly named model). FWIW I know a goodly amount about this product, and even more about its wireless cousin, the DSL-604+.
While the router is yesterday's hardware it is a highly reliable device (when running reliable firmware, which you say is the lastest version).
The router works well with the ADSL Max service, and there is no reason to change it (other than for testing purposes) for a more recent model, until and unless BT/whoever get aound to offering an ADSL2+ service.
I would discount the router as the source of the problem - but if you want confirmation, you could beg/borrow/swap an alternative from a friend/relative/colleague/neighbour for a day or so to check.
I would concentrate on the line issues. Before calling in BT (via your ISP) I suggest that you recheck the internal connections (BT's connection to the master socket, filter, connection to router) and wiggle/tighten things up/swap for alternatives (and give the IDC connections on the BT side a poke). But you know all this, given your other reference to Cisco. You could also try a dedicated filter at the master socket, from Clarity, ADLNation, or Solwise
There is of course no need for a filter on the ADSL line connection to your modem/router, but these products will provide better isolation between the ADSL frequencies and other equipment you have. However, filtering at the master socket may not suit the topology of your network.
Once you have eliminated (?) wiring issues, then it's down to the quality of the line. I would clear the router's line error counters, then keep an eye on them for a couple of days. What you are looking for is a rapid increase over a short period which will indicate a line problem.
You can also monitor your model of router using an SNMP-based utility which you can download from here:
This site (Trevor Roydhouse's brainchild) is the best source of info on the DSL-504.
FWIW I get 7.3Mbit/s using a DSL-604+ (same communications processor, different modem chipset) at 7kfeet from the exchange.
If all else fails, you will need to get BT (more accurately, OpenReach) out via your ISP - just insist. The thing to watch out for is that if they find no fault after testing with their kit you are likely to be charged. One way to avoid (?) this is to be especially nice to the engineer (cups of tea etc) and claim that the fault is intermittent. This is likely to result in him changing to a different connection pair in the street cabinet, and also changing the equivalent physical connection in the exchange racks. If it is a line problem, this will probably cure it...
Hope this helps
[Aside: I have many routers (don't ask!) but am still using an obsolete, somewhat insecure DSL-604+ while awaiting a comprehensive upgrade to an IEEE 802.11n + Gigabit Ethernet network. I would go so far as to say that the DSL-604+ is the single most reliable item of consumer electronics I have ever used. I trust its imminent replacement will be the same...]
I wouldn't go for an 837 now since it has an older chipset. There's newer models - 850 and 870 series.
There are a bunch of DSL settings that you can tweak including gain and noise margins etc.
Here's one reference.
I did a bit of tweaking, I remember, which did seem to improve stability slightly, not that it was bad in the first place. I arranged for the router to export interface state changes for the virtual interfaces which it will do if there's a retrain etc. and these are quite rare now.
Another option is to get one of the larger chassis and get WIC cards for it - e.g. an old 2600. In the end I went for a 2800 series because I wanted to have the othe upgrade possibilities for later use including the ability to hook in other connections such as cable modem, plus I'm using MLPPP with the provider and two DSL lines and it was more convenient to do that in the router than to mess about trying to do it with Linux or something like that.
I've run a couple of 800 series in a closed cupboard together with the PABX and a UPS for the lot and it has survived OK.
However, I think if I were doing it again, I would arrange an oversized fan with good bearings and a thermostatically controlled speed controller. I use this arrangement on a large APC UPS to pull more air through it when either it is working hard or the ambient temperature is too high. Most of the time the fan idles pretty much silently.
I loved the rack mounted ciscos.. Big heavy squrae box and NO lights.
Might get round to that..
ADSL Max only uses frequencies up to 1.1MHz all those are VHF or UHF so should be well out of the way. But RF being RF a really strong signal (ie mast withing 500m) could be getting demodulated somewhere and causing trouble.
As has been mentioned before have a dig about with the telnet interface and possibly the direct command mode in there, rather than the text menu system normally presented. You can normally get at the actual parameters used but this is pretty low level tweaking and runs the risk of stopping things completely if you tweak the wrong thing the wrong way. Have a dig on the web to see if you can find a command guide for your particular modem/router.
Fairy nuff, the only really stupid question is the one that isn't asked. B-) Does rule out naff extension wiring etc. The filter might still be a source of "trouble".
I bought a nice faceplate one (ADSL Nation XTE2006) it gets rave reviews, but it's worse on my line particulary at night than the soap-on-a-rope plugin BT MF50. Lower SNR and inabilty to maintain >5,000kbps sync speeds were the MF50 can. Worth trying a few different filters? If you trust eBay sellers they can be had for 99p + reasonable P&P or on Amazon for 1p plus unknown P&P...
As you have found out getting someone at your ISP that has the required technical knowledge can be difficult. I thought I saw reference to Claranet, they were one of the more clued up ones. Indian call center doesn't sound like them though.
You wouldn't be saying that if you were sitting behind one of the bloody things in a machine room.
Sometimes I take my ear defenders.
We never went IN the machine room except to swap out kit.
Most of them were managed remotely by telnet or reverse terminal servers..even had telnetable power cyclers on them..and the terminal serers had modems as well, just in case..
Of course. Generally I don't either, but occasionally equipment work is needed.
Post codes out in the sticks are too coarse there is about a mile difference between the extremes of delivery points in our postcode, that is assuming the checker uses the full postcode and not just part of it.
The 10 day initial learning process just sets the MSR and FTR, the modems will sync at whatever they can determined by the conditions at the time of synchronisation. I'm not quite sure what the MSR signifies within BT, the FTR is the rate things have to consistently fall below before BT accept there is a "line fault".
BTW the MSR and FTR *can* be reset by starting another "training period" if they are particulary bad. I had this done on my line as we had two thunderstorms during the first training period and they where very low. I now have MSR 5120 and FTR 4096 before they were something like
2500/1200... I shouldn't bother with your figures.
They negociate at the time of synchronistion the best rate at that time. Multiple disconnects/reconnects will lower the BRAS rate, this sets how fast your ISP can feed data for you into the BT network. The BRAS is set in roughly 500kbps chuncks and is lower than the sync speed. BT cannot/will not buffer data within their network.
If the BRAS gets knocked back, say by a thunderstorm, it should recover back up once the line has been synced at higher, "normal" speeds for about
72hrs.I think you need to try:
Different filter(s). Different router/modem. Get at the settings of the modem to try and force it to sync at a lower speed (set a max sync rate) or sync with a larger SNR/margin.
Hope not. You ain't installing anything that uses telnet in *my* data centre!
"Dave Liquorice" wrote in news: snipped-for-privacy@srv1.howhill.net:
I posted elsewhere in this thread, both about faceplate filters including links to Clarity, ADSL Nation, Solwise and also about the specific router, the D-Link DSL-504. Has the OP seen this?
The DSL-504 is yesterday's technology, but does have good (for its day) internals with a GlobespanVirata (now Conexant) Helium 210-80 twin ARM7 cpu communications processor running ATMOS (aka ISOS). The device has not only has a web-based config interface but also a comprehensive CLI. D-Link never released 'proper' technical reference info, but an index to the CLI commands can be found here:
The device has a modem chipset from Integrated Telecomm Express, and the relevant commands to play with the ADSL settings are listed under the 'itex' command.
The ATMOS command reference manual can be found here:
While I have installed many, I have more experience with the DSL-
504's wireless cousin the DSL-604+ which has a different modem chipset (the GlobespanVirata Titanium) so I can't offer much help with the Itex. The consumer class modems and modem/routers on which the SNR settings can be tweaked are, IIRC, those with a Conexant chipset (Viking) and despite (currently) common ownership are entirely different to the GlobespanVirata devices.I suspect that the router is fine, that a good faceplate filter might be useful if only to rule out certain interference issues, but that it's a BT line quality issue. OpenReach or whatever they're called this week should be able to fix it - however my experience is that in such cases their fix will come about by a trial and error, 'suck it and see' technique, rather than any more scientific approach...
Kind regards
Probably at least 3 within that range. Tony Sayer knows better than I.
Tried an failed..so far. Got telnet all right but no visibly useful looking commands.
The real question is why, when the BT kit is reporting that my max stable rate is 4544kbps, is it allowing me to connect at 5Mbps+
Yup. If I go into town later I'll pick one up at Dixons or whatever.
I think its in london., but I got the trainee. I THINK it was english we spoke...
>
You mean you haven't got firewalling and VPN's on the kit? shame on you.
Bad generalisation. This postcode covers exactly..let me see.. 10 houses. Maybe 11. 9 are all in one place. I am 200 yards further on and the other possible is 100 yards beyond me.
.Ah.So my problem is simply one of getting the link to synch at a lower speed.
How did you do that..and did it affect your connection speed?
Yup. BRAS is at 4Mbps and that is exactly confirmed by IP data tests - I got 3.8Mbps consistently.
I have noticed that once the router shows 4 or 4.5dB SNR - as it is now
- there are no issues.
I am convinced that the only problem is that the router is connecting at an unsupportable speed - and as you have indicated,a useless speed too, since the downstream link is throttled at 4mps anyway.
>
That link is no longer valid, but I got the earlier command ref and stumbled through.
There seems no way to set the threshold for noise or connection speed.
192.168.0.254> itex helpCommands are:
version line rate mode info txgain rxgain retrain enhance priority alarm getes getsnr getrsd channelmgr setcurve trellis bitswap testPSD tuneperf eneseoc eneseocts dyinggasp vendorid test delay list minds
I upped the rxgain and all that did was cause the modem to show less attenuation and connect at even higher speed. Ditto tuneperf.
getsnr just did nothing. waited a few seconds and came back to he command prompt.
192.168.0.254> itex getsnr 192.168.0.254>Channelmgr looked promising, but there is no help or data on what to type after it!
I am damn sure I know what it is. The router is connecting too near the bleeding edge, at too low an SNR to be safe, but I have no idea how t change that.
Ther seems to be no command that says 'be a little more conservative PLEASE'
I don't think thats quite as many as you think now, no Taxis in that area and the Airwave TX isn't quite that local, the CAA have a site some way away. A lot of microwave isn't used these days being replaced by Fibre there is a DAB TX in the area but quite removed from the bands under discussion.
Theres no MF near there...
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