I know this might be old news to some people. But for those of you that had no clue, you might just be able to lower your ping quite a bit. This is for the ones with ADSL, VDSL, Annex-M, etc. If you're hooked up to a DSLAM at the telestation you should be good to go, I think.

As I've understod it, you ISP sends you data in chopped up packets that are made to avoid any interference when (interleaving) packets get lost on the way due to noise burts, etc. That means you don't have to loose data which is nice, but it takes just a while longer for them to reach you with this method. Yes, that acctually means greater latency. The opposite to interleaving is called fastpath where you try to send it all without any chopped up packets, "just bring it, if I miss one I don't care". That means a lower latency but a risk of loosing signal quality. You could experience packetloss (I still have 0 PL) if you're unlucky. Another sideeffect is that you could loose some bandwith (in my case the upload got a bit worse).

Wikipedia entry about the techniques

I called my ISP (Swedish "Bredbandsbolaget" and asked them to turn off interleaving and let it run in fastpath instead. I'll post some results below, but all in all it was a great success. Download bandwidth stayed the same, upload got worse, but hell I don't care. Latency was approx up to 40% lower with fastpath then with interleaving. I do believe some ISP already run fastpath as default, but some don't, "BBB" sure didn't. It took them 5 minutes to remotely switch and my ping was greatly reduced in an instant.

Hope this might be of some help to others. The customerservice I spoke to called it "pingfilter", so if they don't know what the hell you're talking about they might just use another term for it. I'm no expert but ask questions if you got any. It would be nice to see if others get the same results aswell, and we could get some info on which ISP that can swith or are already running fastpath as default.

Upload cut in half? Ouch. Still, if you don't need to upload (only play games + light surfing?) -- go ahead!

Most UK ISP's will put fastpath on by request, personally it lowered my ping by about 8ms.

In Spain there are only 2 ISP's with fastpath ON, but in other ISP's they don't turn it on, no matter how much people call to their support phone number asking them to turn fastpath on :/. They either enable it by default or don't enable it at all.

And BTW ping difference are bigger here, 20-30ms

I suppose you use one of those ISPs time?

Great news Gore. I live in London now, so might just try that. Seems like my ping could be a bitter better then what I have now (25 to xs4all, 31 to foppa, 39 to pangela). What pings do you get and what ISP do you have? I'm on O2.

in my country all ISPs offer the option to enable fastpath for a monthly fee (~ 2 eur). some ISPs have it turned on by default, specially on 16mbit and higher connections. it's supposed to lower the ping to the 1. hop to 10ms. in my case it lowered my ping by 25-30ms to 10-13ms.

In my country I would contact Consumer Ombudsman about that monthly fee for a setting. It's not like they have to keep pressing the button.

Yeah, a monthly fee for pressing a button ONCE seems illegal. A one time administration cost sure, but monthly fee, no thanks!

totally agree, but that's the deal here with all ISPs. a one time fee i could understand, they need somebody to make one click in a software ;p

when the first dsl connections were available here, interleaving was on by default and most people didn't know about fastpath. you could call them and ask for it, they just turned interleaving off for free.

guess by the time more people found out about it, too many wanted fastpath on, because they play games online and so they made it a new feature and advertised it for online gaming. low ping = extra money.

Hagge, AFAIK O2 don't offer the option to toggle fastpath, I think you have to be on BE (they are the same company); O2 is more a mass-market product, whereas BE is targeted at the professional/gaming/enthusiast market).
Then again if you've got 31ms to Foppa maybe fastpath is already enabled.

Yeah I'm on Be*, and HangTime is dead right about O2 not using fastpath :/ I'd say it's possible to get 25ms in game to foppa.dk from London (I get 26-27 in dos) having seen people get 4ms to bbc.co.uk Maybe when fibre becomes available I can too!

As it was said, interleaving is a way to make ADSL connections more fault tolerant. This is especially required when the distances between a central and the subscriber are few kilometers long. Also notice that if you are using IPTV, without interleaving the IPTV will suffer from errors quite a lot, even if you had a very good line.

Also note that most of the Annex-M connections still require interleaving to work properly, but lately some manufacturers have managed to make it more stable using fastpath, but it's not that commonly used anyway.

That being said, yes, the interleaving does increase the pingtime. If you are not so far away from a central, fastpath should be used in normal Annex-A (ADSL/ADSL2+) as long as the line attenuation and noise margin are good.

In Funland, almost none of the ADSL connections use interleaving, unless they are used with IPTV. ISPs also tend to change from interleaving to fastpath if the customer requests it, for free of course. Making customers to pay from this is the same as giving them the finger.

Hmm well my attenuation is pretty high (56) so I only get 5mbish speeds. It rarely drops though, with a 6db noise margin which I can change if needs be.