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Chrysalis · 25-04-2010, 16:15

your 2 examples.

BT shape certian protocols to insanely low speeds, so it only works when you throttle users down to sub 200kbit on things like p2p.

TalkTalk also traffic shape which skews their figures but are upgrading to increase their allocation per customer 10 fold and are rumoured to remove traffic management later this year for their LLU customers.

The cable isp's in america by 2012 plan to allocate 1mbit per end user.

But the key thing here is contention works far better when the shared pool of bandwidth is larger.

so 100 users sharing 100mbit is far better than 10 users sharing 10mbit even tho both are the same contention ratio. VM's shared pool of bandwidth is split into very tiny portions so requires a lower contention ratio to handle moderate to heavy use. Entanet are a good example of this, they were able to originally share their entire BT central bandwidth across their entire national customer base on ipstream, when they moved to 21CN WBC they then had fragmented their customer base into smaller groups, this led to problem areas (sound familiar?) some of their nodes which had a good balance of light residental users vs business customers were ok, others which were no longer able to be subsidised by the non residental customers struggled with much lower performance and more congestion. When bulldog tried using small shared backhaul on datastream (only 2x the end user's burst) it was a disaster.

I think we will disagree on this point here, my judgement on VM is how it deals with its worst off customers stuck in a ring fenced node with severe congestion whilst other isp's are able to have a fairly equal congestion applied across their entire customer base so they all suffer in tandem sharing the pain. The evil variance on adsl instead is line lengths.

When you pointed out to me in another thread VM are able to mitigate congestion by going down to around 15:1 contention this said it all for me, especially when NTL were quoting 20:1 in their TOS some years back. So at one point they used to contend around that level and clearly since then corners have been cut and overselling increased. I feel you making the mistake so many isps make in that you assuming as burst speeds go up usage will not go up with it, and assume that only a tiny proportion of users use their connection moderatly, I disagree on that, the users who only browse a few websites and read email are shrinking rapidly.

But congrats to VM, by ring fencing off problem areas they also in affect hiding the weakness of their infrastructure to more parts of their customer base so the problem appears less severe than it is. The fact they wont move users of my port to another highlights this, as it would then probably create congestion for other users who dont see it now.

25-04-2010, 16:15	#197
Chrysalis Inactive Join Date: Sep 2003 Posts: 12,047	Re: VM to begin expanding its cable network your 2 examples. BT shape certian protocols to insanely low speeds, so it only works when you throttle users down to sub 200kbit on things like p2p. TalkTalk also traffic shape which skews their figures but are upgrading to increase their allocation per customer 10 fold and are rumoured to remove traffic management later this year for their LLU customers. The cable isp's in america by 2012 plan to allocate 1mbit per end user. But the key thing here is contention works far better when the shared pool of bandwidth is larger. so 100 users sharing 100mbit is far better than 10 users sharing 10mbit even tho both are the same contention ratio. VM's shared pool of bandwidth is split into very tiny portions so requires a lower contention ratio to handle moderate to heavy use. Entanet are a good example of this, they were able to originally share their entire BT central bandwidth across their entire national customer base on ipstream, when they moved to 21CN WBC they then had fragmented their customer base into smaller groups, this led to problem areas (sound familiar?) some of their nodes which had a good balance of light residental users vs business customers were ok, others which were no longer able to be subsidised by the non residental customers struggled with much lower performance and more congestion. When bulldog tried using small shared backhaul on datastream (only 2x the end user's burst) it was a disaster. I think we will disagree on this point here, my judgement on VM is how it deals with its worst off customers stuck in a ring fenced node with severe congestion whilst other isp's are able to have a fairly equal congestion applied across their entire customer base so they all suffer in tandem sharing the pain. The evil variance on adsl instead is line lengths. When you pointed out to me in another thread VM are able to mitigate congestion by going down to around 15:1 contention this said it all for me, especially when NTL were quoting 20:1 in their TOS some years back. So at one point they used to contend around that level and clearly since then corners have been cut and overselling increased. I feel you making the mistake so many isps make in that you assuming as burst speeds go up usage will not go up with it, and assume that only a tiny proportion of users use their connection moderatly, I disagree on that, the users who only browse a few websites and read email are shrinking rapidly. But congrats to VM, by ring fencing off problem areas they also in affect hiding the weakness of their infrastructure to more parts of their customer base so the problem appears less severe than it is. The fact they wont move users of my port to another highlights this, as it would then probably create congestion for other users who dont see it now.