back to article ISP blows the whistle on router chip 'fault'

One of the UK's best-respected broadband providers has raised concerns about the reliability of the world's most popular ADSL chip. Zen Internet has uncovered a potential problem with the Texas Instruments AR7. The chip is at the heart of about a third of routers in use worldwide today - including Linksys and Netgear kit. …


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  1. Simon Williams

    I'm suffering from this at the moment...

    My ISP is Zen and I've tried two different netgear routers - both of which contain this chip and I suffer from CRIPPLINGLY frequent cutouts with the ADSL and the speed is VERY slow.

    But is it the ISP or the chip-set!? I don't really want to buy another modem/router if it isn't that (unsurprisingly...) and *all* of my mates have netgear routers :(

  2. Jude Bradley
    Thumb Down

    Dodgy Chips

    I bloody knew it!!! My Zyxel 660 , provided by me from the very dodgy B* ISP (the world's worst ISP in my opinion)

    has been suffering cutouts and crap connections ever since I recieved it. Nothing but trouble, I tried flashing the router, but *T's proprietary router wouldn't accept it,

    Eventually the router died, (just like my ISP), I binned both:

    Happy ever after!

  3. TrixyB

    Sky Broadband Users BEWARE!

    Looking at the list of routers the WAG54Gv2 is on the list!! Is this why the connection is so awful without a router reboot?

  4. Karl Lloyd


    I have experienced similar problems with Orange's LiveBox (v1). It wasn't on the Wikipedia list, but does anyone know if this is an AR7-based router?

  5. Lickass McClippers


    ...I notice that the Netgear DG834G is on the list. I've been using one of these for donkey's years, without problem. However, my other half has had no end of grief with her's. This router is shipped as standard by Sky, and after cruising a few forums etc about issues with Sky Broadband, this could well be the answer. Good bloody luck trying to get it fixed though, Sky Broadband 'Technical Support' are fecking useless..!!

  6. Anonymous Coward
    Anonymous Coward

    Any recommendations?

    We're experiencing the same thing - tried replacing filters, had BT test the line - apparently no problem, but still frequent disconnections with a Netgear router.

    Anyone had the same experience and found a router/manufacturer that works better?

  7. Ian


    So if it's in a third of ADSL routers why aren't a third of ADSL users worldwide suffering the problem?

    Sounds more like the common factor is Zen and they're trying to shift the blame.

  8. Anonymous Coward

    Paying for Bt and Chipsets

    If your ISP has told you to get an engineer out, FFS charge them!

    BT - No fault found.

    Yup must use the same chips in their own NTE's on ISDN Pri's, as they says this everytime, then as if by magic, they start working again....

  9. DSL Angel
    Jobs Halo


    I discovered there is physical layer issues with the AR 7 when testing ADSL 2 + CPE nearly two years ago for a UK ISP!!! - When compared to other vendors such as Wintegra, Broadcom and Infinion chipsets.

    TI can and have improved this performance and it depends on the PHY code that the router vendor has embedded in their router firmware.

    Thats half the story, not to mention also the routers analogue front end design, this varies from manufacturer to manufacturer and "cheap routers" often have reference design front ends which perform less well against those who research and design their own, which i beleive Thomson do for their Speedtouch range.

  10. Anonymous Coward
    Anonymous Coward

    Zen is rock solid

    I use Zen. Didn't have a dropout for 3 years using a vigor router. In the last year I've used two different netgear routers, both of which drop off at least once a week.

    They do cost less than half as much as the vigor routers though!

  11. Stephen Gray

    Netgear is the most stable router I have tested

    I have worked for 3 different ISP;s and 90% of the disconnects are caused by user equipment. Remove all equipment from all telephone sockets in the house and connect to the master socket, I have even been out to our users premises after they had sworn blind no equipment was on the line and I have removed all CPE and Hey presto, connection restored

  12. Kyle

    Infineon seem to admit the problem here...

    The problem looks to be caused by fluctuating signal to noise ratios, which is common with Max ADSL and on long-ish lines. The router seems to drop the connection to try and get a faster one, causing a cycle where it's almost fighting with the exchange equipment.

    Zen aren't involved at this point, it's between your router and the BT kit, and this looks quite similar to a problem with Draytek 2800 routers found earlier this year.

    The line "It could very well be. You give up robustness if you don't compromise on data rates." pretty much states that they'll favour speed over stability, which is at odds with what BT push for.

    In fact, the article even states that the chip is made and therefore tested in Germany, who don't have Max ADSL to test on. It's likely they just weren't aware of the problems until someone spotted that these routers seem to commonly be linked to ADSL dropouts.

  13. Anonymous Coward

    What a load of tosh...

    Now all network issues are the fault of the AR7, unbelievable...Every chipset has issues, being AR7 or whatever. New features and code updates in the DSLAMs require new updates. To say that this chipset or that chipset is at fault is absolute rubbish without further explanation. How was this concluded? If two thirds of the worlds ADSL2+ chipsets are AR7, why hasn't it been raised before?, because it's not an issue. How many routers were tested and how many vendors?

    What DSL code was tested from Infineon? Mine has had 7 updates in 2 years.

  14. Anonymous Coward

    Good Question!



    By Ian

    Posted Monday 22nd October 2007 12:28 GMT

    So if it's in a third of ADSL routers why aren't a third of ADSL users worldwide suffering the problem?

    Sounds more like the common factor is Zen and they're trying to shift the blame.


    It appears that the fauolt is based on Annex A and NOT Annex B. Hence the issue is mainly based in the UK and in Australia. And yes there has been some cases listed in Aus.

  15. David Bell

    RE: LiveBox?

    Orange's liveboxes are rebranded speedtouch routers. They do not contain the AR7 chipset.

  16. Stuart Barnett

    Similar but not quite ;o)

    I had huge issues with my ISP, Plusnet. Line dropping, speeds of a massive 108kbps (that's right 2x dial up) on an Upto (meh!) 8Mb line. I did everything they suggested but no joy. Eventualy got fed up and moved to Orange and had the same problems. Common denominator ... BT line. With baited breath and the threat of divorce I called them out risking the near £200 call out charge. Guy said "... can't see anything wrong". "However, you've got an old style master socket, internal wiring on an external wall, a worn connection point where the telegraph line joins the house and a frayed telegraph line, but none of that will impact on your performance!" He changed the lot and I'm now stable at 4Mb and have never seen it drop below 3 Mb.

    It was financial gamble calling them out but as has been pointed out, BT's infrastructure is so old it's wearing out. Even Steptoe would leave it alone!

  17. Dimitri
    Thumb Down

    Zyxel routers suffer from this - tested in 3 countries

    My two zyxels (dumb purchase I know) both exhibit this problem and do so in the UK, Greece and Germany. At least they're consistent:(

  18. Joe


    I would not trust anything that BT says as far as end of copper line is concerned. My experience of BT is that a lot of their engineers will pass the buck on ADSL faults, after all its just like any technical thingy, unless you get the "cream of the crop" engineers you aint going to get the result you were hoping for. Easier to blame hardware or customers equipment.

    Our experiences of Linksys routers/wireless networks have been nothing short of useless. They overheat if let sitting flat. We have installed all sorts of ADSL equipment from Zyxel, Cisco, Draytek, Linksys, 3com, Dlink, Netgear, dynalink, and others.

    I have to say the most reliable and configurable of the lot is the Netgear DG834G version2 which ..... DA DA..... uses the chip and we never get any problems. In fact it is one of the best routers for holding onto low SNR we find.

    One can only assume that their are outside influences at work. Does'nt BT normally supply crippled speedtouch routers. Personally I reckon the router market is pushing suppliers to supply lockin routers in turn for a big fat pay back, bit like life insurance companies do for finiancial advisers.

    Oh, and finally one peice of advice, if your router is a netgear install it on its side in an area with lots of airspace. And generally if your ADSL router does get hot you may get frequent lockups or dropouts. Stands to reason really electronics dont like getting really hot. HTH someone.

    And yes, I have to agree with Jude, checkout your ISP and make sure you are not suffering a ISP dropout. First thing check your router stats and see if you got sync. Probably may well be saturation of ISP network. Basically if you have Sync, means you got ATM over BT ADSL network. No IP, or roter not connecting to your ISP then its an ISP problem.

    Couple of useful tools. see

    Dial 17070, press option 2 listen for pops, clicks or noisy/buzzy line.


  19. Azzaka - Zen

    AR7 Fault

    The problem manifests on lines where the SNR changes up or down in succession. It can also occur on rare occasions where the SNR rises above 9 to 12dB. You will also see issues when there is excessive noise on the line. Most routers will adjust the sync accordingly, however the TI-AR7 chipset results in intermittent connection problems, aswell as No Sync and No Auth.

    It is not a case of Saying that all ROUTERS are at fault. It is suggesting that with the current BT Infrastructure the AR7 chips can not cope with the excessive noise levels, and hence they manifest as an intermittent connection or No Sync and in some cases Auth faults.

  20. Kyle


    Please bear in mind that there are a range of different models of Netgear DG834, and only certain ones contain the AR7. YMMV, as ever.

  21. Craig Chambers

    I doubt that it's Zen's fault

    I've been using an Alcatel Speedtouch 510v4 router with Zen for 5 years now and run an always on server at home. I only had my first line related dropout about two months ago and that wasn't Zen's fault either.

    While I was investigating the issue with Zen, my wife remembered that a BT engineer (technician to those of you with an MEng) had been messing with the telegraph pole by our house at the same time as it stopped working.

    I actually recently bought a Netgear router just to use as a wireless access point, but reading this I'm glad that I stuck with my trusty old Alcatel to manage my ADSL connection rather than trying to have an 'all in one' solution.

  22. Anonymous Coward
    Anonymous Coward

    Never had this problem...

    Over here in Oz I've had a Linksys AR7-engined unit and never had a problem with it over the past 18 months.... and that is with Optus (which Australian readers will know are on par with Telstra).

    Having said that I always used it with fairly short runs and low noise levels.

  23. brainwrong

    But that is what ADSL is for....

    "He insisted that the chip is mature and reliable, but conceded that ADSL drop-outs are a fact of life on decades-old infrastructure."

    Maybe I'm wrong, but I thought the whole point of ADSL was to work on the "decades-old infrastructure" because it's too expensive to replace it all with something better.

  24. Anonymous Coward

    Netgear DG834G

    I've had a couple of these in constant use for almost 3 years without a single problem. I was somewhat suprised to see it on the list!

    I do wonder if this is going to turn out to be something else...

  25. Anonymous Coward

    ADSL is cheap get over it!! If you want reliable 24-7 connectivity get a leased line

    As anyone who works in the industry knows, when ADSL came along it caused lots of problems for ISP's. Try explaining to a customer that is paying several grand a year for a 2meg leased line why paying fifteen quid a month for a DSL connection is a bad idea. Answer - rubbish reliablity, disconnections, contention (i.e. effectively sharing your bandwidth with 20/50 other users). This was deemed fine for home use.

    ADSL is a way of getting high bandwidth over old and outdated copper wiring and as such will always be a bit doddgy. The problem is how it is sold to the customer.... This is never explained on any website, speed is totally theoretical and so is reliability. If your "last mile" wiring is rubbish and you live quite a distance away from the exchange, then your connection will always be bad. Change ISP as many times as you want and you will still have connectivity problems. Only answer is to move house. This will be the case until we have the entire country wired with fibre and this is what we should be pushing the government and business for.

    Some routers are better at dealing with noise on the line than others, looks like this chip-set can't deal with excessive SNR. I have seen a zyxel 660H with an uptime of over a year on a very good quality phone line

  26. Andrew Davenport
    Black Helicopters

    More than just the AR7!

    I have had a customer of mine recently start upgrading their lines for the benefit of higher speeds, they were using the Netgear DG632.

    Despite their support site clearly stating that the latest firmware will allow these to run at ADSL2+ speeds up to 24Mb the devices crash very regularly.

    BT have repeatedly checked the line and said all is ok.

    We tried the device on our line (100% stable with a DM111P up to 8Mb) and it crashed on that too, which to me ruled out the line and BT.

    We sent the DG632 off to Netgear and they came back saying it would not crash but their test labs could only test up to 2Mb!!!!

    How are they supposed to truly validate a device up to its maximum potential speed without the equipment needed to test it?

    So, in this case i think Netgear know there it a problem with the DG632 and wont do anything about it, they are not offering a refund or an exchange. Fair enough the device is out of warranty but they have not removed the statement on their site about supporting ADSL2+ up to 24Mb.

  27. tardigrade

    Linksys WAG54

    I didn't believe any of this until I saw that the Linksys WAG54 was mentioned. Now it all makes perfect sense.

    Everyone without question that I know who has used one of them be it a WAG54G, WAG354 or whatever has had intermittent connectivity problems with them.

    They are awful routers and wherever I've used them they've all had to be ripped out and replaced.

  28. Ian

    ...I notice that the Netgear DG834G is on the list. I have the rev 1.x

    ...I notice that the Netgear DG834G is on the list. I have the rev 1.x and it has worked fine with the very occasional disconnect. I'd be quite concerned if I suddenly start getting more (coincidence I had a net outage this morning after months without?)

    I'm not a big fan of linksys (cisco home?) but my extended experience of belkin is abysmal. I've installed 3 - 4 belkin routers for people and had multiple problems with their slow ass software and wireless networking faults. I recommended one guy paid a little more and replaced his belk with a new rev netgear and all his troubles disappeared, snap to setup also.

    I'm with f2s, a tipex subsidiary ... I'm hoping to go to adsl24 soon just to get away from TIscalli and piPEX :-|

  29. Dave

    Taking the lid off

    As I've got a DG834 and it's been pretty good despite a poor S/N ratio (other routers have struggled), I'll have to take the lid off and see what chip it's got. I know the Draytek router I had didn't like the link at all, the DSL300T was mostly OK and the Speedtouch USB thingy behaved most of the time and I blame the USB side for its issues.

  30. Hedley Phillips


    I was with Pipex for over two years and didn't suffer any dopouts and then I moved to Zen and it was appaling. I went though a very lengthy process with Zen (great tech support) involving removing everything from all sockets and using the master socket, replacing everything including my cables and finally replaced the router and problem fixed.

    Zen at the time said it seemed to be a problem with the SNR and my Linksys router.

    Now, the funny thing is I have swapped my Linksys router with... a Linksys router! (can't confirm the model number just now so don't know if the replacement is affected by the chip issue) And I didn't have a problem before Zen, like I say, over two years with Pipex and not a single issue until the day we moved to Zen.

    My friend down the road also moved to Zen and had exactly the same problems.

    Is it the chip or the ISP.

  31. Anonymous Coward

    The blame game

    I think Zen have done themselves no good at all with this 'announcement'.

    First of all, and any ISP should know this all too well, depending on BT engineer's 'tests' is courting commercial suicide. I had the experience of complaining for nearly two years that a certain line, which was poor at the best of times, became near unusable (voice and data) during and after wet weather. It took them THAT long to discover that a cabinet in that infamous 'last mile' was flooding and had standing water in it!

    Secondly, I'm not too sure the chip is to blame either. I'm responsible for three Netgear DG834N units, which initially were fine, around the beginning of the year one started dropping with increasing frequency (Zen), another dropped occasionally (Demon) and the last, my personal unit (Zen), was stable - AND the furthest from the exchange...

    As the year wore on things got worse, but only for the Zen connections (the Demon DG834N issues resolved themselves when the telephone cable finally broke and lay pathetically huddled in the street - something even a BT engineer had to admit was a fault),

    Even mine started dropping a couple of times a week, the other became nearly unusable.

    After a few calls to Zen, always courteously dealt with by English speaking staff in the UK - but with no resolution of the issue, I decided to dig a bit deeper. Logs and error messages suggested DNS issues.

    Eventually I decided, after much unsuccessful experimentation, to go OpenDNS - and like magic, all was fixed.

    Now I'm not going to state that Zen's DNS provision leaves more than a little to be desired, but my experience was that removing it from the equation resulted in a complete cessation of issues.

    Ah, you say, but, you are talking about DNS issues, the issue here is 'loss of connection'. Well that's a very loose term. What exactly are they talking about I wonder? The 'connected' 'link light' going out? Or 'the internet isn't there any more'?

    DNS failures of the type I've observed, and suffered myself, are certainly a 'loss of connection' to all intents and purposes. And easily confused with an ADSL connection or sync failure.

    Zen's problem is that their announcement makes it sound as though they are passing the buck. And from my limited experience, that my be the case. Not a smart move when you are one of the most expensive ISPs in the country.

  32. Stu


    I dont think its the chip that is responsible -

    I have a NetGear DG834G v2. This uses the AR7 and I get a consistently great connection, I have NEVER suffered a DSL connection dropout (quite a claim I know, but true), I get a consistently excellent 850Kbps from good fast websites (IE7 reported file download speed), and I'm signed up for an 8mbps connection. So I'm not getting 8mbps but its as close as anybody would ever get to 8mb over ADSL given natural line losses.

    Zen can come round my house and see it for themselves, they're talking shit.

    And believe it or not, I'm not with BT at all, I'm with Bulldog, an LLU line. Yes, Bulldog!!! :-) I put my successes down to the fact that I'm not with BT.

    So I'd put these problems down to the aged infrastructure too. It looks like I got really lucky where I live!


    BT get off yer fat arses and install Fibre, that'll stop the whining.

  33. Neo

    It's not all bad...

    The industry generally accepts that some ADSL chipsets perform better than others on 'less than ideal' connections. If your line stats are good then you shouldn't have problems with the AR7 chipset. If your stats are borderline or poor then maybe things can be improved by changing your setup (1) or tweaking the router (2). If you have tried all the possible improvements with your existing setup then you may want to try a different router with a different chipset (such as the Alcatel chipset in the Speedtouch 'frogs' that BT use [as mentioned in the article]).

    I would like to mention that we offer free technical support and advice to anyone experiencing problems with their AR7 (and other) routers on our website:

    We also have a custom AR7 firmware which is packed with features.




    Neo, Admin

  34. Andrew Gordon

    Not just Zen (& not just long lines)

    I have the same problem with Demon (unsurprising, since Zen and Demon both use the same underlying BT product).

    In my case, I have two AR7-based modems (AVM Fritz!Box Fon Wlan), and two

    ADSL lines (one Demon, one Be).

    Both the modems had been working reliably for more than a year in other locations

    before I moved in here (one of them on a Demon line in the same exchange area).

    Either modem will work fine on the Be line (giving about 12Mbit, stays up for days on

    end), but if connected to the Demon line will disconnect and retrain every few minutes during the night (but OK during the day). When the Demon line is up, it gets very close to 8Mbit (never less than 7.5).

    I'm not right next door to the exchange, (maybe 1km away as the crow flies), but hardly a long or marginal line.

    I'm guessing it's a firmware incompatibility between BT's DSLAMs and the AR7 when handling particular kinds of noise - not clear whether my Be line works because Be are using different DSLAMs, or if I that line happens to pick up less noise - both lines are in the same house, but then my line at the old house gave no trouble despite being same

    modem, same ISP and approx same distance from the same exchange (and giving

    the same almost-8M data rate)

    I'd be much happier if BT turned down the data rate to give some more margin and

    so a more reliable connection - but they won't do this, just insisting that my modem

    is faulty!

  35. Anonymous Coward

    Are you sure ???

    I've been on ADSL with Plus.Net for 5 years or more now.

    Firstly I had a Solwise hard wired router - it was great - never broke down.

    Then I changed to a Billion Wireless unit - it maintained faultless connection to the NET but the wireless connection frequently dropped forcing a hard reboot.

    So I tried a Linksys WAG54Gv2 - this had fantastic Wireless reliability but do you think it would maintain a net connection? - no way, no how.

    So finally I've arrived at the Netgear DG834(G), not sure which version but its a reconn unit so unlikely to be the most up-to-date. Nevertheless it is rock solid in all aspects - I can't praise it highly enough, even when I have a powercut it comes back fine - whereas the linksys and Billion failed to do so.

  36. Albert

    Moved from Sutton to Byfleet and keeps dropping

    Was living in Sutton, Surrey and has an 8Mb connection with Bulldog. Worked perfectly after initial teething.

    I moved to Byfleet, Surrey and my broadband from TalkTalk keeps dropping (DSL light goes out)

    My connection speed is about 2Mb, so a lot slower.

    It’s the same router in both locations – on the list…

    My expectation was that the lines in Byfleet are older, so not up to the job and just sometimes drop. Been living with it for a year. Maybe I’ll try a new router to see what happens.

    I intend getting a new router when 802.11n is ratified, so hopefully I won’t have to wait long…

  37. Anonymous Coward
    Thumb Up

    Good job Zen

    For all those bashing zen over this, what would you rather have?

    An ISP that is seeing a pattern of faults that are down to and issue with the customer equipment and not tell you about it thus getting you a BT charge if you ever have an engineer come out?

    Or an ISP that would inform you about what they have seen so that you can make the informed choice of if you want to risk having BT called out and getting charged?

    The AR7 issue does not effect fixed rate DSL lines, so if you are on fixed rate (512k, 1024k or 2048k) you will not suffer this problem problem. It has only been seen on DSLMax lines, and not all DSLMax lines ether. You can have a router running AR7 on a dsl max line and it all work fine, then take the same router to another line and have the issue. Its a hard issue to pin down and no one has ever said its the only chipset issue that's out there, however my hat goes off to them for pointing it out as I for one don't want to be charged for engineer visits.

    Its also worth pointing out that AR7 chipset routers were being shipped out long before DSLMax came about, so were never tested for compatibility with those types of lines. You can hardly expect something to run perfect with no issues on something its never been tested on.

    From what I understand any router manufactures can pay BT to test their equipment at the BT Labs and get a full report on its compatibility and issue's, now I know speedtouch have this information and make it available to ISP's (as I called them and asked them about this), but it seams that the same cant be said for several other leading brands who did use AR7 in some of their range. In fact the typical response is that they haven't done such testing.

  38. Simon Chapman

    Try alternative firmware

    I use a Netgear DG834G v2 on a Zen connection and all is fine even though it uses the AR7 chip (the newer v3 uses a different chipset I believe). However, I used to suffer a lot with disconnections caused by fluctuating noise ratios when I was using an earlier version of the firmware, V3.01.25. Since upgrading the firmware to V3.01.31 ten months ago, I have had no more problems.

    The problems reported by Zen don't seem to affect lines with stable SNRs so only folk with a) a fluctuating SNR and b) the AR7 chipset would see disconnections. In any event, it is worth experimenting with different firmware versions before declaring the AR7 as the villain.

    PS. There isn't a chance in Hell that Zen are trying to shift blame here. They are possibly the most honest and technically proficient ISP in the country.

  39. Anonymous Coward
    Anonymous Coward

    Mixed bag with Linksys

    I'm on a fairly poor line with 6+dB fluctuations during a 24-hour period on the SNRM. My most successful modem (not router) was the Linksys ADSL2MUE (which used an AR7 chip). It would stay connected for weeks.

    Initially I got on well with the Linksys WAG54G (also AR7) series, but they couldn't hold a connection in the cold or wet. And they did get hot-hot-hot.

    My current router is a Netgear DG834GT (Broadcom BCM6348 chip) and it's as solid as a rock.

  40. Anonymous Coward
    Anonymous Coward


    I've been using one of the affected routers for 2 years in this house with Zen with not one single dropped connection (and I would notice drop as I work from home as a web dev) and suddenly 2 months ago I get MASSIVELY reduced speed - down from 5-6mbps to around 1...

    I've tried using another netgear router (that also has the offending chipset - typical...) and this also suffers from these drops (and also *never* had any problems with this hardware in a different location for 2 years..)

    It amazes me that suddenly 2 routers (different models, bought at different times and locations) have suddenly started working intermittently

    Zen and BT have been *completely* useless.

    Who do I not pay for the past 2 months 'service'..?

  41. Anonymous Coward

    Long Lines and BT 'BRAS PROFILE' system.

    Not only have I found some routers are more stable than others on my long rural line (Attenuation 50) but the real problem is BT's BRAS (IP Profile) system - once it sees a disconnection your speed profile is reduced and you have to wait around 3 days for it to recover!

    Why can't I have my normal speeds back the next day if I manage to reconnect at my 'normal' line rate??? I believe LLU providers don't use this profile system, but for me (and most others) my exchange only offers BT providers.

    BT - PLEASE PLEASE take a look at your BRAS Profile rules...

  42. Anonymous Coward

    Chips and Modems

    Just to clarify

    "BT staff test for a wiring problem using hardware based on chips made by Speedtouch - rivals to the AR7"

    Thomson Multimedia Broadband-Speedtouch make the modems/routers - their latest ones use Broadcom chipset, older ones used Alcatel - which is also extensively used by BT for their exchange equipment. If you are tempted to go for an older one you need to be aware that the firmware is no longer updated.

    And to confuse matters more both Linksys and Netgear also use Broadcom ADSL chips in some of their devices!

    Of course its not only the chipset the design of all the electronics in the devices is very important.

  43. Anonymous Coward
    Anonymous Coward

    Linksys WAG354G

    I don't remember having an ADSL link problem with my Linksys WAG354G in the 2+ years I've had it. It usually syncs at 8128 Kbps - a bit lower if the S/N margin gets too low but whatever the speed, the link seems rock-solid.

  44. Anonymous Coward
    Anonymous Coward

    "suddenly started working intermittently"

    "It amazes me that suddenly 2 routers (different models, bought at different times and locations) have suddenly started working intermittently"

    It shouldn't, necessarily. It's been perfectly clear (to anyone with a clue and a bit of honesty) that as DSL penetration goes up, and in particular as high speed and MaxDSL penetration goes up, inter-punter crosstalk would get generally worse.And that fluctuating sync speeds and intermittent connections would be the inevitable result. It was clear that for some small number of punters with particularly unfortunate BT-side wiring, that things would get a *lot* worse, and that there'd be no money in the BTw/Openreach picture to do anything worthwhile about it. This was of course all pooh-poohed by most industry *insiders* because it wasn't "on message". Welcome to the real world.

    As has been pointed out, DSL is not a leased line, there are no SLAs. But that's no excuse for hype and misinformation (which, for the avoidance of doubt, is not a refernce to Zen).

    Zen do have a few LLU lines as well as their majority of BTw lines, which may use different exchange kit than BTw use. Anyone know if Zen's experience on their LLU lines come into this picture?

    I've got a (non-Zen) 2Mb fixed service and I'm sticking with it for now, together with the associated antique DSL604 router, it's usually rock solid. The dear old DSL604 is one of the small number of SoHo routers which has the smarts to tell me a bit about the DSL signal characteristics and quality at any given time, which I can also record if necessary for troubleshooting purposes (not that anyone would actually be able to use it for anything interesting, because there's no money in the BT kitty for faultfinding and repairs). Does your modem/router have that capability? If it doesn't, imo it's not "fit for purpose" as a high speed DSL modem.

    Mind you, the same kind of signal quality information is also available to BTwholesale from their DSLAMs in the exchange, should they choose to do anything with it, but while I was an outsider following this stuff (which I don't any more) I never saw any evidence BT were making worthwhile use of any automated diagnostic or maintenance capability, even though in some cases they'd invested (wasted?) tens of millions of pounds in kit from Teradyne and others.

  45. Graham Lockley

    Sorry but...

    'I'm with Bulldog, an LLU line. Yes, Bulldog!!! :-) I put my successes down to the fact that I'm not with BT.'

    Im afraid you only hand off in the exchange, the cable up to Bulldogs equipment is still the same as everyone elses and this is the area that causes most problems. When you went LLU, the wires between you and the exchange didnt get magically altered :)

  46. This post has been deleted by its author

  47. Anonymous Coward
    Anonymous Coward

    Balls (crystal)

    Of course it was clear, even without a crystal ball, that inter-punter crosstalk would get worse. The phone wiring is decades old in many places, it wasn't designed for anything other than voice frequencies, and distance (loss) barely mattered with voice whereas with DSL the signal quality is critical, and some faults which cause no noticeable voice problem can be a disaster for DSL. (DSL is medium wave radio frequencies down a phone wire, so it's no real surprise the behaviour is different from the voice frequency behaviour)

    The crosstalk problem was known about but barely mattered when the fastest sync speed was 2Mb and penetration was less than 5% of phone lines and broadband was "engineer installed" (with the now-trendy-again "faceplate filters" - if you don't have one, GET ONE now) and used mostly by techies (or people with access to techies).

    Back then, before Pipex invented mass market broadband, the chances of a pair of problematic lines both having broadband were small, but if there did happen to be a problem, BT/Openreach had their Special Faults Unit to troubleshoot the odd few cases that simple "pair swapping" didn't fix.

    Now penetration is a lot more than 50%, speeds are often a lot more than 2Mb, consequently the general level of background noise due to crosstalk has increased, consequently everybody's modems shout louder in order to be heard above the background... The number of ""problematic" setups where there is serious interference between two pairs (two customers) on a route is no longer negligible, but you'll not find anyone willing to admit it. Also, there often aren't any spare pairs that haven't already been tried, but will anyone admit that?

    And did I mention that there's no money in the kitty (and no viable tools in the toolkit) for DSL faultfinding and fixing? BT 21CN. It's about reducing operational costs, so long as it doesn't mean investing in serviceability and maintenance.

    You can call that overselling if you want though, it's a lot shorter :)

  48. Anonymous Coward
    Anonymous Coward


    I have had zen using a draytek router for 3.5 years and it has never dropped off. We are in village with crap BT lines, I never get above 3.6 when supposedly 8 meg adsl.

    Just about to replace computers, suppose I should keep the old roter after reading this.

  49. Ben

    informative thread ,

    For what its worth ..........

    Isp , Zen.

    H/ware , in the list , not physically checked chipset type .

    Distance to exchange , 1.4Km .

    Line noise , there but not bad , at vox b/width , increases with

    speed at data b/width as explained above and visible in stats.

    No problems at all , not running always on though , for lots of

    reasons .

    Zen ? not the cheapest , and so far from the worst

    ( i asked them some questions before i signed up ,

    as you do ? and they replied , which was nice )

    they're in another dimension , all good .

    Great site , humour , education , THE information i , i , i ,

    f*ck i've turned into Donald Sinden .

  50. Marc-Oliver Kalis

    not faulty Chip, but flawed and useless 'BT'

    I think, people don't realise, that it's actually not the chips fault, since it works very successful in millions of other routers, but the extremely poor and rotten BT infrastructure! An infrastructure that is being used to cash in through a quasi monopoly, but that they are not willing to maintain.

    Any one who has read the article with just slightly open easy, will recognise the pattern.

    In terms of speed the majority of Europe is far ahead of the UK, only where there has been some un-bundling, the line quality is reasonable.

    I have tested AR7 routers (AVM Fritz!box, Linksys, Netgear) and non AR7 (Speedtouch) and can really pinpoint, that it is due to the chipset.

    That doesn't mean that the chip is the reason.

    It is absolutely normal, that equipment form the same manufacturer will communicate significantly better than equipment, that is "just compatible"

    It would also not surprise me, if BT deliberately withheld this information, so they can cash in on "unnecessary call-outs".

    Interestingly, when you go for BT Broadband, as a normal consumer and opt for a router provided by them ,you will always get one with a Speedtouch chip set.

    In itself this may not hold up very much, but it certainly is an interesting coincidence.

  51. This post has been deleted by its author

  52. Anonymous Coward
    Paris Hilton

    It's a conspiracy

    Balmer or Paris Hilton is behind this TRAVESTY!!!

    Either way, one of them is going to smoke a turd in hell for this!

  53. Tampa Dave


    nuf said.

    It's adsl! No one cool uses adsl.

    Consider this a free and un-documented feature.

  54. Anonymous Coward
    Black Helicopters

    its all a bit silly

    most of you people only decide to complain now... bah humbug to you all... gettin as bad as americans!!!!!

    we have had two routers in our broadband lifetime... both use the AR7 chipl... and we never had a problem, we only had to change the the first one because it died from old age...

    its most likely that zen are just have a shit time on their network and want to pin the blame somewhere else

  55. Anonymous Coward
    Anonymous Coward

    AR7 issues

    Porblems here with Netgear routers! - all seem to be dropping or resetting at 29, 49 and 59 seconds according to the ISP's log - got fed up with this and went cable my 20Mb service (18 in real terms) is far, far better. It seems it's down to BT's policy of keep ovehead feeds regardless - and what copper network? it's all aluminium now!

  56. Anonymous Coward
    Thumb Up

    Incorrect mate

    "its most likely that zen are just have a shit time on their network and want to pin the blame somewhere else"

    Its seams you are a little confused as to how adsl works via BT Wholesale.

    The router connects over the BT retail line, to a BT Wholesale DSLAM in the exchange, the Username and password details are then authenticated by the BT RAS servers which then pass the session over the ATM/Central network to the ISP.

    So stability of sync is in no way related to the ISP's network.

    Its also worth noting that the article and people and know have repeatedly said that the issue only happens under certain line conditions so its possible you can have AR7 routers on DSLMax and have no problem, thus your comment of I have 2 routers both AR7 and their fine so its cant be right isnt valid.

    Also I know of several cases where people have had intermittent sync, they changed their AR7 routers for ones using another chipset and the line worked a lot better. Proving that those particular faults were the AR7 issue. I also seen people with intermittent sync and they put other routers on and it didnt resolve is so they were suffering another problem. Its just one more thing to look at if you have an intermittent connection. Nothing wrong with an ISP looking at all possible causes of a fault.

  57. Anonymous Coward
    Anonymous Coward


    Seems the AR7 might not be too keen on interleaved lines in the UK. I got that from a router manufacturer. I assume Zen (Phil Long is not one to shoot his mouth off) have been getting the same info?

  58. Bob D

    Hours of instability .......

    I spent many days recording the noise margin "reported" by my Netgear DG834v2 after my circuit became unstable following LLU. What I discovered was that although the device with this chipset (and another brand of modem using the same chipset) would negotiate connection at the defined noise margin, over a matter of 10-20 minutes it would deteriorate until the DSL was unusable. This seemed to be a problem that commenced with ADSL2+. I spent many many hours on the phone to my ISP trying to identify the problem but in the end I concluded the DG834 couldnt cope with a slightly noisy circuit.

    I replaced it with a 2Wire 2700 from ebay and all my problems went away.... and came back with the DG834v2.... so I got rid of Mr Netgear's box and since then I've enjoyed a fairly consistent 5mbs + on a 40dB attn line about 2km from the exchange.

    How refreshing to see that someone else has identified a similar problem, take heed anyone having probs with this chipset, you could be amazed how quickly the "fault" goes away when you stuff it in the bin!!!!

  59. Anonymous Coward

    Please stop

    It is paining to see different comments from half-baked idiots who don't knoiw anything about ADSL . Zen are partly at fault for openly saying it is a fault with the chipset, but in reality, it is, "INCOMPATIBILITY WITH THE CHIPSET AND SOME BT LINES". It is not a fault, incompatibility.This is no way a fault with an ISP because, the dropouts are the connection dropping between your router and the exchange which belongs to BT. Exception is if you line sync (i.e. connection to the BT DSLAM in the exchange) stays up and you still lose connection.

  60. Anonymous Coward

    @ Albert

    Well, what a coincidence. I am also connected to the Byfleet exchange and I also have TalkTalk broadband and would you believe it - it drops out all over the place, exactly as you describe. Sometimes we lose it for days at a time.

    I've got a Netgear DG834PN, slightly different from the ones mentioned here. I don't know what the chipset is but I'm going to open it up and find out.

    To be honest, there's no easy answer to this. The service is of course crap, but then again it's bargain-basement cheap. I can ditch them in November without paying the penalty fee and I don't mind paying more to get something reliable, but as many posters have pointed out, ADSL can be shite whoever you get it from.

    I was considering switching to Virgin cable, but their reputation for customer service makes me very scared indeed.

    At the risk of starting another war, is cable a better technology in practice than ADSL?

  61. fon

    check the SIMPLE stuff first!!!

    this link may help....

    As it says, before you waste your money on another modem/router, to have it fail in the same way.....

    check the phone socket, lines filters(they can dry out, and newer ones will be better now than 5 years ago!), length and quality of cable, connections, anything that cable passes that could create interference, etc, etc...

    basically I would find a place as near as possible to where the phone cable comes in, and connect the modem there.. then cat5 network cable from a router...

  62. Andy Dempster

    My experience

    I've had ADSL for the past 6 years, 5 years of those with Zen. I've used a DLink DSL504 up till 2 months ago when I switched to a Netgear DG834G v3. My first year of ADSL was with BT Openworld and I had nothing but trouble with the connection, several things were tried but eventually I switched over to Zen when my 1yr contract was up. The service improved dramatically and I had no problems until I switched to ADSL MAX just over 2 years ago.

    The Dlink started disconnecting twice a day (so I bought the Netgear - same trouble) and I had real difficulties getting the connection back up involving a full power cycle of the router. I have a dedicated line for ADSL hanging off the master socket with a faceplate. No external filters, no extra devices. According to my research neither of these modems have the faulty chipset in question which leaves me in serious doubt as to the credibility of this claim.

  63. Marc-Oliver Kalis

    not faulty Chip, but flawed and useless 'BT'

    I think, people don't realise, that it's actually not the chips fault, since it works very successful in millions of other routers, but the extremely poor and rotten BT infrastructure! An infrastructure that is being used to cash in through a quasi monopoly, but that they are not willing to maintain.

    Any one who has read the article with just slightly open easy, will recognise the pattern.

    In terms of speed the majority of Europe is far ahead of the UK, only where there has been some un-bundling, the line quality is reasonable.

    I have tested AR7 routers (AVM Fritz!box, Linksys, Netgear) and non AR7 (Speedtouch) and can really pinpoint, that it is due to the chipset.

    That doesn't mean that the chip is the reason.

    It is absolutely normal, that equipment form the same manufacturer will communicate significantly better than equipment, that is "just compatible"

    It would also not surprise me, if BT deliberately withheld this information, so they can cash in on "unnecessary call-outs".

    Interestingly, when you go for BT Broadband, as a normal consumer and opt for a router provided by them ,you will always get one with a Speedtouch chip set.

    In itself this may not hold up very much, but it certainly is an interesting coincidence.

  64. Kris Lord

    Sky Broadband

    I had this problem with the DG834GT supplied by SKY.

    I'm about 400m from the exchange and get 16Mbit, however still got dropouts.

    I found the problem was caused by uPnP problems in the firmware.

    Disabling uPnP has completely fixed things, currently been connected for 700 hours without a problem whereas i was getting at most 6 hours previously.

  65. fon

    check the above posts..

    Andy Dempster, have you also tried *with* a line filter?? Vocal-band signals can interfere...

    also try Disabling uPnP as above.. and talk to Zen about a full ADSL MAX line test... this should weed out other forms of interference...

  66. fon

    ask the experts on adslguide...

    more technical details in this forum....

  67. Paul Dickinson

    What's good then?

    I know it's subjective, but I suspect I have a dodgy BT line. They say it's ok, but I suffer with drops in speed in the space of an hour, by about 80%.

    What ADSL2 routers are good/reliable with poor lines with noise?

    Which routers DON'T use AR7?

This topic is closed for new posts.