Kitz Forum
Broadband Related => Broadband Hardware => Topic started by: Roy22 on November 18, 2007, 03:53:10 PM
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I'm about to replace my ageing BT Voyager 105 USB modem (on BT Broadband) with a wireless modem router.
Online reviews seem mostly positive about the Netgear DG834 series. Working up this range from 834 to 834G, 834GT, 834PN and 834N, price and capabilities increase....but so do complaints of various problems.
Ignoring price for a moment, where would you aim in this series? Reliability is key. And is video streaming ever going to be viable with any of these?
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There's no single best answer to that question unfortunately, because different routers work best on different lines. I've used an 834GT which I flashed with the unofficial UberGT firmware, and I was pretty happy with it. But I've since changed to a Speedtouch ST576 which gives better performance and stability on my averageish line. Ideally you would try out several different routers to determine the best one for you, but I realise that isn't very practical.
I expect that others will be along shortly with more comments.
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Thanks for the reply. For the benefit of others who may want to post, I've a 2mbps connection, attenuation of 44.5dB and SNR Margin of 22dB.
I can't easily get to grips with the mixture of reviews for this series which think they are either 'brilliant' or 'unreliable junk'. Doesn't make make the choice easy!
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In the past the Netgear DG834(G) v1,v2,v3 have always seemed to be pretty reliable and seem to have good success on longish lines and be able to keep hold of a connection where some others cant.
However, very recently theres been a bit of a warning that the chipset in the 834(g) (and some other routers does seem to have problems on some lines that "flap". We've not seen any evidence of this here and the router does seem to have stabilised many long lines
My own personal thoughts are that there is perhaps a bit more to this than the just chipset alone - possibly also something to do with the kit in the exchange.
Until more info is released about this , caveat is now there. v4 doesnt have the same chipset so is considered ok. Theres a list of routers that contain here (http://www.linux-mips.org/wiki/AR7).
The broadcom chipsets in the DG834GT also seems pretty stable.
In view of the above the current flavour seems to be Speedtouch routers.
However saying that mr_chris has found that his netgear dg834g (v2) was more stable on his line than a Speedtouch 576.
So thats back to the theory that if you can match the chipset in your router to the chipset used in the the dslam at your particular exchange, then the line will perhaps be more stable.
Some routers will advise you the chipset in the dslam.
For eg from the connection page on a speedtouch
Vendor ID (local/remote): TMMB/ALCB
ALCB Alcatel
BDCM Broadcom
GSPN Globespan/Virata
IFTN Infineon
TMMB Thompson Multimeia Broadband - Alcatel
TSTC TI (Texas Instruments)
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Some routers (such as the netgear) show the chipset vendors in hex
ATUC ghsVid: 0f 00 41 4c 43 42 00 00 -> ALCB exchange DSLAM
ATUR ghsVid: b5 00 54 53 54 43 00 00 -> TSTC your router
Thanks to John2007 (http://bbs.adslguide.org.uk/showthreaded.php?Cat=&Board=dslrouter&Number=3084669)
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What chipset is in the v4 ?
I have a v3 which I believe is Broadcom.
I'm using my 2wire2700HGV at the moment though.
I'm also curious to know if the chipset in the router and the DSLAM are compatible does that give a more stable connection.
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The V3 has the TI AR7 chipset for the ADSL side and Broadcom for wireless, so it's half and half. The V4 has an entirely Broadcom chipset. (Thanks to Kitz for finding that out).
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>> I'm also curious to know if the chipset in the router and the DSLAM are compatible does that give a more stable connection.
Its a theory that has been brandished about for a quite a while (by those more knowledgeable than me).
Although there isnt any hard evidence to prove it is the case, there have been reports by some users that it has helped. The amount of reports that it has helped is sufficient to lend some evidence that there may well be some truth in this theory.
The discussion surrounding compatibility with the dslam chipset and router chipset has only really come into the forefront over the past couple of weeks after the disclosure by Zen about concerns over the AR7 chipset on some lines.
The AR7 possible chipset problem theory is still pretty new and afaik its not been confirmed one way or the other as yet.
>> Thanks to Kitz for finding that out
I cant really take the credit for that since I dont have either of these routers.
I just asked in the Zen Forum if some of their customers with these particular routers could perhaps help and find out, by being kind enough to telnet into the shell using a linux command and post the results... so we would know.
If you want a read, then the news article about this here (http://www.theregister.co.uk/2007/10/22/zen_ar7_infineon_bt_fault/).
Be very careful though when reading the comments - theres many that have immediately jumped to the wrong conclusion that it is the cause of their problems. take for eg this one (http://www.theregister.co.uk/2007/10/22/zen_ar7_infineon_bt_fault/comments/#c_81380) - which cant be true because the sky router is a DG834GT which has a broadcom chipset. iirc some one else jumped to the wrong conclusion about the orange box too.
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Kitz
I am looking to buy a netgear router and have another thread running on this forum. Have read through the comments here and if I have understood them, the DG834G is OK with V4 chipset.
Having looked at one of these the specification given doesn't seem to make any reference to this. What do I need to look for?
Thanks
gom
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Which Netgear models can be tweaked to lower your noise margin ?
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Kitz
I am looking to buy a netgear router and have another thread running on this forum. Have read through the comments here and if I have understood them, the DG834G is OK with V4 chipset.
Having looked at one of these the specification given doesn't seem to make any reference to this. What do I need to look for?
Thanks
gom
>> the DG834G is OK with V4 chipset.
I believe so... it has a broadcom chipset.
>> specification given doesn't seem to make any reference to this.
Its not anything they do make reference to.
This sort of info you can get if you have one of the routers already and either physically open up the box to look.. or much easier if you can telnet into the routers shell and it gives you the results back.
I asked a few zen users with different dg834g's to telnet into the shell and paste the results back. Previous versions of the dg834g had a AR7 chipset.
Whilst atm there does seem some concern over the AR7 chipset my own feeling are that there is much more into this than just the model of the router chipset. The previous versions of the DG834g have had some good results on long lines and actually managed to stabilise some that were having problems with many other routers for it to be a chipset only problem.
To try put it into perspective the equivalent could be like saying that all intel chipsets in PCs are bad. There's other variables. Dell PCs and Aldi PCs etc etc could all have the same chipset... but only some of them have problems. Theres something else in this mix Im sure... it could be the way the manufacturers put the router together, it could be the firmware, it could be the physical line, it could be compatibility with the dslam at the exchange... it could also be something to do with Interleaving and the way the router handles it.
As yet what the combo is that causes the specific problems hasnt yet been proven, other than the AR7 chipset is in use.
iirc you have very good line stats therefore I seriously doubt that the problem discussed would materialise on your own particular line anyhow.
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Which Netgear models can be tweaked to lower your noise margin ?
The ones reported definitely able to work with v8 of DMT are Netgear DG834GT/DG834NB/DG834PNB,
In theory if v4 of the netgear dg834g also has a broadcom chipset... it should work. (as long as netgear havent done anything to disable the underlying command functions).
Need a guinea pig with a v4 to test this out and reply back before we know for sure. So if anyone has a v4 and wants to give it a try - and if it does work (or even if it doesnt) then please let us know.
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Kitz
Thanks for your reply it would seem that my choice should be fine.
It seems you have a number of users we used to see on CA web site. Despite an upgrade it still seems to be suffering from difficulties in opening up, can take forever sometimes, but it's not as bad as before the upgrade, we persevere.
gom
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>> it would seem that my choice should be fine.
Obviously the AR7 chipset report has been something we do have to bear in mind - so it does make us hesitant against recommending it now. :/
Its also right that rizla and others should bring to your attention that its not as future proof as other routers. They wouldnt be doing "their job" properly if they didnt say so.. afterall you could kick yourself if say in a years time you were on an exchange that offered this facility and you had to buy another because you wanted the faster speeds.
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I have just installed a DG834Gv4 into a clients house today and it is a 5km line that was hardly ever able to sync and a of 6 hours ago he now has a stable 2MB line :) .
Another success story!
I use them on problamatic lines all the time now(Since 1 1/2 years ago after reading about it here ;) ) and would definatly recommend them.
James
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Thanks for the feedback James.
The v4 actually has a broadcom chipset - but as regards v2 + v3 I really have seen too many reports where the netgear dg834(g) does help longer lines to believe it is just down to the chipset alone.
I'm not trying to diss what Zen say, but to tar _all_ AR7 chipsets I really am not sure about - and certainly think there is another yet undiscovered element in there too.
It also doesnt seem to fit in with the many reports on this and other forums that the netgear has been able to help lines sync that couldnt with other routers.
If it was _all_ AR7 chipsets I would have thought there would be a heck of a lot more complaints before now.. and more what there are now.
/my 2p
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So overall the Netgear DG834 models are usually good on long lines,am I correct ?
I have another questiion if I may ?
I believe that your noise margin will usually come down every two weeks if your line is stable to a default of 6db.
Can BT set it at the exchange so it is always at a set level say 9db or 12db and it won't come down ?
Can your ISP ask them to lower it from say 12db or 9db to 6.
Or would the customer be able to override this with say a Netgear or a Speedtouch and tweak it down themselves to a 6db noise margin ?
Thanks.
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>> So overall the Netgear DG834 models are usually good on long lines,am I correct ?
Well in the past many users have had sucess with them. However we cant be blase and ignore what has recently come out about the AR7 chipsets. I dont think zen would have released the informationation on a whim. There possibly is something but just what the full contributing factors are yet we really dont know - hence the hesitation right now over the whole situation and I dont think anyone would put their neck on the line and say for sure one way or the other.
>> I believe that your noise margin will usually come down every two weeks if your line is stable to a default of 6db.
This has been mentioned before - some users reported that it does. Ive seen someones do it after 4 weeks. Ive also seen cases reported where it doesnt.
Sorry but this is one area where you will find there is little information about what is supposed to happen and no-one seems to have been able to find out exactly just what the triggers are for the reduction of target SNR.
>> Can your ISP ask them to lower it from say 12db or 9db to 6.
Yes its one of the configurable attributes.. earlier this year Mr_Saffron on TBB and James from Plusnet used to have success in getting this done. However over the past few months BTw seem to be a bit more "no can do" when it came to these requests. Even many good ISPs can play ticket tennis with BTw of late to try and get this done :/
>> Or would the customer be able to override this with say a Netgear or a Speedtouch and tweak it down themselves to a 6db noise margin
The netgear dg834g v1-3 doesnt have this facility.. The DG834gt does as do most speedtouches.
If you use DMT can can tweak your target SNR yourself.
However its important to bear in mind that you are tweaking a percentage.. therefore if your target SNR is profiled at 9dB then you should be able to get it down to 6dB. However if your target SNR is 15dB, then although you could bring it down to say 12dB, I dont think 6dB is possible.
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Many thanks.
It's all a learning game little by little. :graduate:
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I did this with my draytek and i set an option called ADSL Codinggain 7 using telnet and this basically lowers it by 7db. It was a massive success for me and as kitz say you can do this with DMT with the DG834's. Most chipsets can only lower it by 6-7db.
Plus net lowered mine to 9db but it took them a while as BT kept saying no. The reason they do this is probably because they don't want the phone calls about problems(which it can obviously caused if changed to much. I recommend doing it in small steps(but leave 20mins between attempt as not to flag your line as having a problem(constant resync).
James