The 10 day training period ...

Hi Guys,

I've just had our new BT 21CN Annex M ADSL line installed and activated (day 3 today). It is supplied via BT from a smaller ISP - Talk Internet (who provide the handoff / IP allocation / bandwidth).

Given this is the first ADSL connection I've ever had, I'm a bit wet behind the ears, but I'm eager to make sure I'm getting the best combination of performance AND stability that I can.

I've ordered a Zyxel P660R-D, but in the mean time, I'm using a BT 2700HGV (v4.25.19 SBC 'unlocked' firmware), which I believe is only Annex A capable.

The line is working well and hasn't lost sync at all, but the speed is a bit disappointing. I ran a lot of speed tests, with varied MTU values (in the absence of the ISP telling me the recommended value). 1400 appears to work best and provides an average speed of ~9 Mbps, but indicative values are 14Mbps (from ISP and SamKnows). So .... slightly clearer

Current average speed: 9Mbps
Indicative (expected) speed: 14Mbps
Modem: BT 2700HGV (v4.25.19)
Distance from exchange: 800m
Socket: BT Openworld (new master socket)

DSL Line (Wire Pair): Line 1 (inner pair)
Protocol: G.DMT2+ Annex A
Downstream Rate: 20653 kbps
Upstream Rate: 1036 kbps
Channel: Fast
Current Noise Margin: 5.3 dB (Downstream), 7.9 dB (Upstream)
Current Attenuation: 28.0 dB (Downstream), 14.7 dB (Upstream)
Current Output Power: 18.4 dBm (Downstream), 10.0 dBm (Upstream)
DSLAM Vendor Information: Country: {0xB5} Vendor: {IFTN} Specific: {0xBE71}
PVC Info: 0/38

My cause for concern, is that the sync speed is 20MB, but the actual speed is MUCH lower.

During this "training period", is there anything special I should be doing to prompt a speed increase? Is the sync speed even relevant?

Should I be resetting the modem manually to force a re-sync?
OR
Should I leave it well alone, and make sure it doesn't re-sync?

Sync speed is king. Second to that is what your IP profile is set to, visit www.speedtester.bt.com to see what that is

No need to force a reboot of the router, the 20Meg is very good, and things may improve, a lot hinges on what the IP Profile is set to

@Andrew

Thanks for the quick response. I'm not on the site with the ADSL connection at the minute, but I think I'll drop tonight by and run that test.

I'll post back in ~30 mins

I was waiting for other views before commenting, Andrew, and agree with you that the sync is good for the attenuation.

I would in fact say it is exceptionally so, implying that something isn't being reported correctly. The target noise margin looks to be the standard 6dB.

You may not be able to get a BT speedtest - they have a server failure at present and access to speedtests is difficult if not impossible.

Where are you setting the MTU?

You can set it on both PC and router - and if the router is lower than the PC you can get a slow down.

I have seen some 2700's that have 1400 as the default - ones not setup for the UK/BT market which, if you are tweaking on your PC would suggest you have hit the right/matching value.

Try setting the router to 1492 and then te PC to 1478 or 1492

@MHC

I've just been trying it, but to no avail! I'll be around for another 1hr, so hopefully it will be remidied by then. It just hangs at "Checking user details"

MTU is set on the router only. PC is still on defaults.

@RobertoS

That doesn't sound good! Based on the att. what would you expect in terms of speed?

Edited by deleted (Wed 30-Nov-11 18:46:01)

When i was using 21CN i used PPPoE 1500MTU

seemed to work a lot better than PPPoA.

Which OS?

If Win7 then you will be OK as it will work out what value. If XP and the PC is set to 1500 you will have some issues.

XP. I'll revert back to 1500 then.