Draytek Vigor 120 causes slower speed

Hi,

I swapped my Thompson 585v7 from O2 for a Draytek Vigor 120 and I got a surprising DROP in speed of approx 2MB to just under 4MB, was just under 6MB with O2 box. This is connected direct to main socket ADSL filter

I thought the Vigor 120 was supposed to be good and so I was expecting the same if not higher speed. Any idea of causes and if I should just go back to the O2 box and hack to make it a pass through unit ?

Also not sure if it's a v1 Vigor 120 or v2. No indication any where it's v2 so i assume v1. Firmware is latest version too.

any ideas?

Are you referring to Sync or throughput?
Is it using the same modulation (e.g. ADSL 2+ G.992.5) as the Thompson? How do the line stats compare?

The latest firmware is different for the V1 (3.2.4.4) & V2 (3.2.6) so it would help if you know which you actually have.

I'm refering to speeds based on the Speed test on this site.

Same modulation.

Line stats about the same
9db SNR
42-43 line attenuation

Firmware is 3.2.4.4 and model is Vigor120 (no v2 ) so I'm working on assumption it's a v1

First step is to get the router stats from both devices and compare them.

This rules out variations that are possible to the great beast that is the Internet

In reply to a post by ianfuture:

Line stats about the same
9db SNR
42-43 line attenuation

What sync is achieved by both devices? Are they different?

What are you using as the end point for the PPP session? Could this be the cause of lower throughput (if the sync speed is the same?
It may be worth connecting the V120 directly to your computer and creating a PPP connection to test and compare?

i have
i just can't post them here for some reasons as they're screen shots. Info in previous posts sums up main stats

In reply to a post by panda:

In reply to a post by ianfuture:

Line stats about the same
9db SNR
42-43 line attenuation

What sync is achieved by both devices? Are they different?

What are you using as the end point for the PPP session? Could this be the cause of lower throughput (if the sync speed is the same?
It may be worth connecting the V120 directly to your computer and creating a PPP connection to test and compare?

I'm on O2 so use MPoa connection. both sets of stats collected direct from connection to router/modem. What do you mean by sync speed and PPP?

In reply to a post by ianfuture:

I'm on O2 so use MPoa connection. both sets of stats collected direct from connection to router/modem. What do you mean by sync speed and PPP?

OK, so ignore the PPP question, as Be/O2 use a different method.

The sync is the rate at which the modem as connected to the exchange. It is reported as 'Up Speed' & 'Down Speed' within the admin pages of the modem. Or you can use the command 'adsl status' when accessing the modem via telnet to grab the info.

What we need to determine is whether the modem is actually connecting at a lower speed (which will be revealed by comparing the connection stats) or whether it's something else.

In reply to a post by panda:

In reply to a post by ianfuture:

I'm on O2 so use MPoa connection. both sets of stats collected direct from connection to router/modem. What do you mean by sync speed and PPP?

OK, so ignore the PPP question, as Be/O2 use a different method.

The sync is the rate at which the modem as connected to the exchange. It is reported as 'Up Speed' & 'Down Speed' within the admin pages of the modem. Or you can use the command 'adsl status' when accessing the modem via telnet to grab the info.

What we need to determine is whether the modem is actually connecting at a lower speed (which will be revealed by comparing the connection stats) or whether it's something else.

it is syncing at slower speed:

O2 box: bandwidth up/down : 1095/6740 kbps

Vigor 120: upspeed 1041041 downspeed 4278857

So in that case it is not a throughput issue, but that the O2 box which will be set up to cope nicely with the o2 hardware at exchange connects at 6.7Meg, and Vigor at 4.2 Meg

6.7 Meg at 42dB attenuation and a 9dB margin is pretty good
4.2 Meg is only a little below what I'd expect off the top of my hard for a 9dB target noise margin.

So the variation may just be differences in how the vigor is coping with your line length.

Which O2 package are you on please?

In reply to a post by MrSaffron:

So in that case it is not a throughput issue, but that the O2 box which will be set up to cope nicely with the o2 hardware at exchange connects at 6.7Meg, and Vigor at 4.2 Meg

Unfortunately even with O2 box wasn't getting 6.7MB, more like 5.7MB-5.9MB

In reply to a post by MrSaffron:

6.7 Meg at 42dB attenuation and a 9dB margin is pretty good
4.2 Meg is only a little below what I'd expect off the top of my hard for a 9dB target noise margin.

So the variation may just be differences in how the vigor is coping with your line length.

Really? That's disappointing about the Vigor. I had high hopes for it. I was thinking of contacting O2 to see if they could poss go down to 6db and see what would happen to speed, even with O2 box.

In reply to a post by RobertoS:

Which O2 package are you on please?

A legacy one (but I'can't remeber the name), so allegedly "no traffic mangement". Why ?

I've a Netgear DM111P modem kicking about as well as an old Belkin combined modem/router. If i can be bothered (or the "boss" lets me) I may hook those up and see what speeds they give me too

Hmm, i'd seen some posts about the numerous firm ware versions available off the Draytek FTP site, so thought I'd nothing to lose trying those out. Just tried the STD version and got a small increase to approx 4.3MB in speed test and sync stats to approx 5000000 down kbps

http://www.coolwebhome.co.uk/calc/calculator.php?par...

Shows around 7.4 Meg at that attenuation might be possible with 6dB target.

Personally I've don't recall knowing the Vigor 120 as a good device for speed, but that is not to say some people

In reply to a post by ianfuture:

In reply to a post by RobertoS:

Which O2 package are you on please?

A legacy one (but I'can't remeber the name), so allegedly "no traffic mangement". Why ?

Checking exactly that - legacy or current. I think I had some better reason but that was a lot of wine ago.

Re your reply to MrSaffron since then, your stats on the O2 box show a 6740kbps connection. The maximum download speed (speedtest result) on that would be ~5625kbps.

Edited by RobertoS (Fri 15-Mar-13 22:44:21)

Ah yes. O2 Standard that used to be limited to 8Mbps, or either of the uncapped ones?

In reply to a post by RobertoS:

Ah yes. O2 Standard that used to be limited to 8Mbps, or either of the uncapped ones?

That sounds like it looking at O2 stats it said max sync speed was 8MB

Tried all the Vigor firmwares last night. Best stable speed approx 4.3MB.

Switched back to O2 box and speed straight upto 5.8-5.9MB approx

Out of curiosity I'll try the netgear too and see what that gives me. I suspect somewhere in between the two I think.

What model Netgear, (or have I missed it)? The 834 series with Broadcom seem to sync 100-200kbps slower than the O2 Box II did, (I don't know about newer O2 boxes), but more than made up for it in the tweakability of the noise margin. So you could sync much faster if your line was decently stable.

Also hold sync down to 0dB margin, whereas I found Speedtouches fell over around 3dB.

The Vigor 120 uses an Infineon chipset whereas some isp's such as O2/BE use broadcom equipment at the exchange, so you will get a loss of sync speed. The opposite happened to me as TalkTalk mostly use Infineon equipment ...using a broadcom router (Billion 7800N) gave me ~15 meg sync speeds on a 29 db atten line with Talktalk, yet when i switched to the Draytek 120 my sync speeds shot up to 18 meg.

You need to use a broadcom router such as Billion 7800N, Netgear DG834G/N (some versions) or even Speedtouch ST585v6 for the best sync speeds .

Edited by deleted (Sun 17-Mar-13 13:53:04)

In reply to a post by baby_frogmella:

The Vigor 120 uses an Infineon chipset whereas some isp's such as O2/BE use broadcom equipment at the exchange, so you will get a loss of sync speed. The opposite happened to me as TalkTalk mostly use Infineon equipment ...using a broadcom router (Billion 7800N) gave me ~15 meg sync speeds on a 29 db atten line with Talktalk, yet when i switched to the Draytek 120 my sync speeds shot up to 18 meg.

You need to use a broadcom router such as Billion 7800N, Netgear DG834G/N (some versions) or even Speedtouch ST585v6 for the best sync speeds .

Interesting. I didn't know that. What's the "science" between having same chipsets at exchange and in modem ?

Mainly the firmwares are designed to optimise each other.

Broadcoms also have an optional feature within the standard implemented, to do with "Impulse Noise Protection", which can speed things up if present at both ends.

Edited by RobertoS (Mon 18-Mar-13 23:44:08)

I just wanted to add that I also benefit from chipset pairing.

I dont know why their is a big difference when paired but, my exchange was upgraded last year to BTW adsl2+ (infinion chipset).

I was previously using a Broadcom chipset router which gave me ATTENUATION of 26db, but as an experiment I got a Netgear DGN1000 which uses the infinion chipset. I was very surprised that the ATTENUATION was only 21.8db when the chipset was paired.

I dont know why there is such a big difference in attenuation, but the line is very stable.
Only word of warning is that the wifi on the Netgear DGN1000 is total pants.

In reply to a post by wanapoo:

I just wanted to add that I also benefit from chipset pairing.

I've also benefited from pairing. However one of the difficulties in my experience is that not all modems are able to tell you what is at the other end, even when using Telnet. But maybe I've been unlucky