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stephencooke
stephencooke
12/5/2012 | 4:09:55 AM
re: UK DSL Networks Getting Crammed
Materialgirl:
"So exactly where is the choke-point? Somewhere around where 155Mbps lines go into COs, but where? Does this mean a market exists that is not being addressed?"

My understanding of the UK's CO's (called "Exchanges") is that it is entirely copper on the access side with fiber coming out the back (ie: towards the network). It seems that what BT is offering ISPs is a bandwidth-capped STM-1/STS-3. Increasing the bandwidth available to the ISP is what BT sells (eg: an STM-4/OC-12 linecard). I don't see any technical reason mentioned for not having additional bandwidth available. It seems purely economic (ie: the ISP can get more, they just have to pay for it).

I am sure 21CN will make these things easier to deal with from BT's point of view later on. The issue I see is that, if businesses want to stay on leased lines, E1's, E3's, etc. that the OPEX business case that 21CN is based on may have trouble delivering in the timeframes that they have predicted.

Steve.
materialgirl
materialgirl
12/5/2012 | 4:09:55 AM
re: UK DSL Networks Getting Crammed
So exactly where is the choke-point? Somewhere around where 155Mbps lines go into COs, but where? Does this mean a market exists that is not being addressed?

With so many telecom service competitors in the U.K., it seems odd that such a lack of capacity exists. If customers want more capacity, is there no money in a business to provide it? Why does everyone just rely on BT? Do we have access networks, nationwide backbone networks, and no metro networks in between?
mr zippy
mr zippy
12/5/2012 | 4:09:55 AM
re: UK DSL Networks Getting Crammed
It seems to me that the fundamental problem is that residential broadband has set customers' money verses bandwidth expectations too high.

Firstly, I think people buy their bandwidth not based on their average utilisation, rather, what sort of performance they want for instant or peak utlisation. This is similar to how they buy their PCs, as discussed by Clay Shirky in http://shirky.com/writings/gri.... Further evidence of this is how people seem to disproportionately care so much about how quickly an application, such as MS Word, starts and is available after they click the icon, rather than caring as much about how it performs once it has started, and their using it. Humans are after "instant" statisfaction, or at least statisfaction within no more than 3 or so seconds.

When it comes to the Internet, I expect a web page I access to be displayed as fast as my broadband link operates. Accessing web pages is certainly bursty in nature, however I think it causes people to expect that sort of performance from all applications they use the Internet for, such as file transfers and P2P i.e. constant load applications. I commonly see people trying to buy the largest bandwidth broadband links to "speed up their downloads", so that a 600MB ISO file only takes 5 minutes to download.

Secondly, it seems to me that ISPs in general may not have fully considered the consequences of putting so much cheap bandwidth at the edge, both its impact on their upstream aggregate bandwidth, and the different ways the customers may start using bandwidth, e.g. P2P apps, locally hosted servers, VoIP etc. Maybe they didn't have time to consider those issues due to how quickly broadband was rolled out (by their competitors, for example), and therefore properly build them into their cost structures for their broadband products. Unfortunately, now that customers have certain money verses bandwidth value levels, trying to go backwards and start appropriately re-adjusting for these factors is going to be a challenge.
Petabit
Petabit
12/5/2012 | 4:09:53 AM
re: UK DSL Networks Getting Crammed
A good point. That probably goes towards explaining the high upload figures, but it doesn't explain the high download figures.

What I don't get is, if your contract specifies 50:1, why are you complaining when you get 50:1?

P
jmbieee
jmbieee
12/5/2012 | 4:09:53 AM
re: UK DSL Networks Getting Crammed
I think that the Next Generation Network needs a new Reference Model, like the proposal described in the paper:

http://www.lmdata.es/uets/uets...

We can take as a reference the strategy utilized by virtual circuit networks: when the X.25 protocol at layer 3 made it technically impossible to increase the network speed, the switching had to be done at layer 2 with Frame Relay and later at layer 1 with ATM.
Petabit
Petabit
12/5/2012 | 4:09:53 AM
re: UK DSL Networks Getting Crammed
Oooo a scare story about how contention rates are rising in the UK ADSL network. Which would be interesting if it were in any way true.

The original ADSL platform as rolled out by BT used a fixed 50:1 contention ratio for residential services at the DSLAM - the cards offered 200 512k connections on the front, and had a 2M connection at the back. BT would add a second card if the first one got over 75% full, so residential users would never really see much above 30:1 contention.

The newer generations of DSLAMs allow much more flexible settings for contention ratios, and so BT allowed the ISP to control the ratio of access bandwidth to ATM backhaul pipe size. The ISP can buy whatever size of backhaul pipe they like, and then contend it how they like. Most ISPs have stuck to about 50:1 for residential and 20:1 for business users. Plus.net were one of the frist ISPs to offer lower contention rates last year, and at the time it was pointed out that it was going to lead to problems managing their customer expectations.

No, the real problem with the UK ADSL network is the rise in peer to peer traffic especially BitTorrent. Plus.net publish their bandwidth statistics (http://portal.plus.net/support... and they are well worth studying. Note that on their all-you-can-eat tarrif (Premier) the traffic bare drops at night. Think about it, who is heavily using their network connections at 4 in the morning? In the vast majority of cases the owner is asleep. Add to that piece of data the statement by Plus.net that the top 2% of their users use 60% of the network bandwidth. And that those 2% are using (on average) 130GB a month - that corresponds to an constant load of 400kb/s. How on earth do you average 400k a second, averaged over 24 hours if you aren't running BitTorrent.

P
kentishman
kentishman
12/5/2012 | 4:09:53 AM
re: UK DSL Networks Getting Crammed
I wonder how much of the 4 a.m traffic originates from Spammers? The number of Hijacked computers is quite amazing in my experience. Recently a friend of mine who I built a computer for 2 years ago told me he upgraded to Tiscali broadband 6 months previously and for the past couple of months his internet connection had been little to non existent.

I agreed to investigate the prroblems and it quickly became clear that his computer had been Hijacked and it had one of those nasty rootkit Hijacks running on it. Fortunately I managed to install the Microsoft Antispyware program and this removed the problem. This situation seems a common problem from my experience people upgrade to Broadband but do not put in place the security needed to keep out the spammers.

paolo.franzoi
paolo.franzoi
12/5/2012 | 4:09:51 AM
re: UK DSL Networks Getting Crammed

materialgirl,

The reason is pretty straightforward. If you spend a lot of money to build a network to lower the price of an existing service, then the returns are horrible. Not only will you not get back the money you spent, the incumbent (who has now recovered all of his costs) will just lower their prices.

seven
materialgirl
materialgirl
12/5/2012 | 4:09:51 AM
re: UK DSL Networks Getting Crammed
Dear Steve,
Thank you for the info. What I do not get is this: BT jacks their 155Mbps rates from $70k/yr plus a per user fee, to a $558k/yr flat fee for 800 users, and we do not get an onrush of gold seekers trying to undercut this sudden, anti-Moore's law 8x fee increase. Users want it, ISPs want to keep uers and make money, a huge arbitrage seems to exist, and we have no takers. Am I missing something?
yarwell
yarwell
12/5/2012 | 4:09:47 AM
re: UK DSL Networks Getting Crammed
you probably have a point. Providing untold riches of bandwidth worked fine while the pipes were empty but the huge growth in subscriber numbers has not been matched by an increase in capacity.

BT's CBC scheme shifted the charging from being based on the end user link capacity to a flat rate user link. This means it now only costs about -8 to connect a consumer at 2M rather than about -40 - hence the retail products at -15-25 for 2M.

The standard charging regime, which is still available, is uncompetitive at higher speeds.

We should also remember that the regulator OFCOM has pegged BT's IPStream prices up at a certain level to allow LLU to grow to a stated target of 1M lines. Those of us without LLU operators on our exchanges (ie 4500 of the 5500 ADSL exchanges) get to pay consequently more for IPStream and have no LLU competition from which to benefit.
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