Recently I replaced my Zyxel P-660HW-T1 router with a Vigor 120 modem connected to a Buffalo WZR-HP-G300NH router. It was intended as a stop gap until I can switch over to FTTC and discard the 120 - though the enabling date for that seems to be more distant every time I check.

I am over 3 miles from the exchange (Bath Kingsmead) and the Zyxel could not achieve more than 2Mbps sync rate (BRAS profile ADSL1750). I also have a Netgear DG384 (non-wireless) and that could only sync at ADSL1750 as well.

However when I connect the 120, the BRAS profile drops within a day or so to ADSL500 or even 350. Replace with either of the old routers and the profile soon goes back up to 1750. It appears that the 120 cannot maintain a stable connection at the same rate as other ADSL routers.

Is there anything that can be done about this or is the 120 destined for the scrap heap? Can anyone recommend a DSL modem that actually works?

The 120 firmware version is 3.2.4.3
ADSL Firmware Version: 332201_A Hardware: Annex A

ISP is Zen 8000 Active (IPStream Max) WBMC

Here are the line characteristics with the Netgear router connected
ADSL Link Downstream Upstream
Connection Speed 2112 kbps 448 kbps
Line Attenuation 57 db 15.5 db
Noise Margin 12 db 15 db

Please get the latest firmware - http://www.draytek.co.uk/support/download/V120_3244_332201.zip (at the time of writing).

I am sure this will help, it solved may issues for me. Or, a similar product would be the D-link DSL-320B

Regards,

Neal

Or get a 2Wire 2700 HGV (BT Business hub) off eBay - they are well known as being able to handle long lines much better than any other modems... For example on a 59db line, the 2700 will manage a BRAS profile of 2000. You can quite easily put the 2Wire into bridge mode and configure login from the WAN router you are using...the 2Wire is then just a simple modem.

In my (humble) experience, Drayteks don't handle poor/long lines that well.

But if the Netgear (which will also doggedly hold on to sync on very poor lines, particularly the non-wireless V4 version) will achieve 1750 profile, I'd use that. On the same 59db line, the Netgear manages a 1750 profile, so I squeeze a bit more out of the 2Wire.

Also you have a noise margin of 12db - this is also going to keep your sync down a bit while giving you a bit of stability.

jhurrell wrote: Or get a 2Wire 2700 HGV (BT Business hub) off eBay - they are well known as being able to handle long lines much better than any other modems... For example on a 59db line, the 2700 will manage a BRAS profile of 2000. You can quite easily put the 2Wire into bridge mode and configure login from the WAN router you are using...the 2Wire is then just a simple modem.

In my (humble) experience, Drayteks don't handle poor/long lines that well.

But if the Netgear (which will also doggedly hold on to sync on very poor lines, particularly the non-wireless V4 version) will achieve 1750 profile, I'd use that. On the same 59db line, the Netgear manages a 1750 profile, so I squeeze a bit more out of the 2Wire.

Also you have a noise margin of 12db - this is also going to keep your sync down a bit while giving you a bit of stability.

Wow, how do you get to know all this stuff about which modems handle long lines well? I'm sure it isn't from the manufacturers.
I'd quite like to understand how the attenuation and noise margin affect the line stability and the determination (by BT) of sync rate. Know any good references for this? Can the ISP (Zen) set any line parameters that might give more stability at higher sync rates?

I have updated the 120 firmware (thanks nealuk for the suggestion) and will give it another trial - in a week, after our "main user" goes back to University :wink: otherwise I will only get complaints. Since I am only waiting for FTTC so I can replace the 120 anyway, it's probably not worth trying to replace it in the meantime, but thanks very much for the info.

Is there any information out there about FTTC modems? What are they called technically? Which ones best handle long drops to the street cabinet (I don't know where our cabinet is but I'm willing to bet our house is the furthest from it)?

jeremygerbil wrote: Wow, how do you get to know all this stuff about which modems handle long lines well? I'm sure it isn't from the manufacturers.
I'd quite like to understand how the attenuation and noise margin affect the line stability and the determination (by BT) of sync rate. Know any good references for this? Can the ISP (Zen) set any line parameters that might give more stability at higher sync rates?

The 2Wire is generally acknowledged to handle poor lines well. It has a terrible interface, but offers lots and lots of stats... See here: http://www.kitz.co.uk/routers/2wire_2700_HGV.htm and also here (linked from the Kitz website): http://bt2700hgv.tripod.com/ir1002700HGV.htm

The Kitz website offers all the knowledge about ADSL that you'd ever want to know. Start here: http://www.kitz.co.uk/adsl/index.htm