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Author Topic: How does Interleaving Effect Speed?  (Read 5089 times)

canon

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How does Interleaving Effect Speed?
« on: November 01, 2006, 01:36:56 PM »

By default my IP (Metronet) apply interleaving on ADSL Max to ensure the most reliable connection.
Does anyone know what happens to actual download speeds when it's on.
I ask because the max d/l speed I can get is about 5200kbps yet Metronet tell me that their profile for me is 7000kbps (bRAS = 7392); the BT test says my "IP Profile" is 6500 kbps (apparently the best actual I can get allowing for overheads).
I'm wondering if interleaving is affecting the speeds I actually get and whether it is worth asking to take it off to get closer to the profile figures.
I now have a very stable connection synch'd at the maximum values.
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kitz

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Re: How does Interleaving Effect Speed?
« Reply #1 on: November 01, 2006, 04:04:43 PM »

In theory interleaving shouldnt affect your download speed at all.. it does however affect your latency.

Latency is really only concern to ardent gamers..  who like to be able to claim the lowest ping times. 
In reality the average person would never notice the increased 20ms (thats milli-seconds).

Interleaving.

From what you say its doubtful that interleaving has anything to do with the speeds you are acheiving.  5200 kbps is a respectable speed.. and more likely limited due to the state of the VP at your exchange.

This is in relation to contention where IPStream adsl bandwidth is shared between may users to make it more affordable to all.  I dont know if in the past youve heard of things like 50:1 or 20:1?

Since Ive been on max Ive consistantly synched at 8128kbps and Im on a very good line with no interleaving.
The average speed I attain at peak is more like 3-4Mbps simply because other users at my exchange are also using their connections.
The only time Ive ever been able to acheive the maximum speed was in the wee small hours and during the early days of MAX.

These days BT seem quite happy to let contention kick in so that we are all seeing reduced speeds.
In fact last week.. almost 50% of the UK exchanges were on red.. which means that a heck of a lot of people are going to be seeing some pretty poor speeds :(
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canon

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Re: How does Interleaving Effect Speed?
« Reply #2 on: November 01, 2006, 05:27:29 PM »

Thanks for the info' somewhat re-assuring!
My ISP are doing some checks because of very low download speeds (<700 kbps) in the evening (I know this is above the official problem level of 400) but I suspect that is a contention issue too. I just wanted to make sure and Metronet are willing to investigate.
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kitz

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Re: How does Interleaving Effect Speed?
« Reply #3 on: November 01, 2006, 09:07:00 PM »

Hi cannon

Not sure if you are aware of the BT Wholesale speedtest?
This will help you identify if it is exchange congestion.

When you are getting slow speeds log in to the BTw speedtest and see what that says.
How to perform a BTw speedtest

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EVIL-SCOTSMAN

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Re: How does Interleaving Effect Speed?
« Reply #4 on: November 02, 2006, 12:56:55 AM »

Just to add something, if interleaving is turned on on your line, then your bras profile is likely to suffer, as it did with me, i had interleaving turned on and  i was syncing at 8096, which meant my bras was 7000kbps instead of 7150kbps as it is now since interleaving is turned off, and i sync at full rate of 8128kbps, so they were robbing me of 150kbps and also they added roughly 20-40ms to my ping times, murder when playing games....

If you are getting just a few errors in your line and interleaving is turned on, I think its better to have the higher sync rate and have interleaving turned off and put up with a couple of errors than it is to have interleaving turned on for less than 100 errors aday.

Thats my opinion anyway, and i get the odd error with interleaving turned off, but it doesnt affect my connection at all, i loose about 30 seconds if that in error seconds aday, not much out of 24hours and my ping is good, so i am happy interleaving got turned off.
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canon

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Re: How does Interleaving Effect Speed?
« Reply #5 on: November 02, 2006, 09:58:12 AM »

Re.
Not sure if you are aware of the BT Wholesale speedtest? This will help you identify if it is exchange congestion.
Yes, I've done the BT test a few times, the results are close to what adslguide gives. The BT test tells me that my "IP Profile" is 6500 kbps on every test. See my first post on this thread for the other info'. Thus, I assume the low speeds are congestion.

If you are getting just a few errors in your line and interleaving is turned on
I'm not quite sure how to obtain/interprate errors from my Netgear DG834. The status/stats page always has 'collisions' as zero.
If I follow the instructions from this page http://www.kitz.co.uk/adsl/frogstats.htm for the DG834 there are various errors listed on the report where interleaving is mentioned but I don't know what it means - explanation please anyone with typical/good/bad values?

I'm inclined to leave the interleaving alone (= on) for now.
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