Well an internal network running at 100Mbps is just IEEE 802.3, it has no limits really, except the hardware and quality of cables that are being used.
The problem with fast internet connections is two things:
1. The network infastructure that is in place.
2. The total amount of peering bandwidth that the company and/or network has available to it.
People who think that cable in this country is a state of the art digital network, are correcty. However, the fibre optic part of the network when it hits the little black box down the road. From there on, it is simply Coax, which is why there are physical limits on the speed that connections can run at. Dont forget a large amount of the bandwidth available on the Coax is already used for the inefficient MPEG2 digital television feed whether you have it or not and dont forget that they are only just starting to cut the analogue feeds off, which is partly why speeds are improving in the last 6 months or so. This is why they are really trying to push FTTH, as then available bandwidth woould be almost unlimited, although the government are concerned about the cancer risks associated with FTTH. So until the government get off their high horse, the best hope is DOCSIS 2.0 for a speed improvement.
The other reason exceptionally high speeds are not realistic is to do with peering. NTL amd Telewest could place everyone on 20Mbps connections tomorrow (although it would mean a lot of SACM and STB replacements due to most having 10Mbps ports), but if every single person downloaded from a server that is not on the NTL/TW network, then speeds would seriously struggle.
This is because ISP's don't have unlimited bandwidth, indeed such a thing does not exist. This biggest worldwide connections (IE. the connections that transfer all the data from one side of the world to another) are OC192, and there are only a few of these. They run at around 9.6Gbps, but they cost a hell of a lot to build and maintain such powerful networks. So when ISP's go to companies such as Peer1 and Level (3) and AboveNet, they have to pay high amounts of money to "peer" with these networks, and even more to actually use them for IP transit (the movement of data from their network, using the worldwide netwoeks). In Europe, we are luck as we have several Internet Exchanges located in the major cities arouns Europe (with AMS-IX in Amsterdam being th largest pushing around 20Gbps at times) and these are where all the ISP's and carriers can sort of terminate and meet up with everyone else, so essentially the traffic is very low cost.
However, once outside Europe, bandwidth is is expensive due to the complexity and cost of running networks under the sea etc... And of course ISP's cannot have just one carrier, they have to have many to avoid their customers having problems (not so long ago Level (3) and CogentCo fell out causing all sorts of trouble for US ISP's).
Yes, there are 100Mbps services available in Japan, one of the most famnous is provided by Yahoo!, and I believe they are based on FTTH, however whilst the bandwidth may be great within Asia, it is not 100Mbps international bandwidth, it may be as little as 1Mbps international bandwidth, who knows, but the point is if someone on these services wants to download something from an EU or US server, then they wont get ever get near the 100Mbps mark, even if the server is on a dedicated GigE with only that person downloading from it.
I have tested many different servers from Asia (mainly China Telecom and Singapore data centres) and the bandiwdth is good to some parts of the western world and absolutely appauling to other parts. The reason is peering, the Asian providers dont peer with enough western carriers because of the high costs.
So to summarise all that crap I have just written, even if we get 100Mbps, it wont truely be 100Mbps internet, more like 100Mbps ISP network bandwidth and maybe a few Mbps o internet bandwidth.
I beleieve myself that it is just a numbers game nowadays anyway, consumers think thy need the fastest connections, the more Mbps a comany can advertise, the better. But this simply isnt true. Yes, the jump from 56Kbps Dial Up/128Kbps ISDN to 512Kbps broadband was gigantic. Then the jump from 512Kbps to 2Mbps was fairly impressive. but the jump from 2Mbps to 24Mbps is barely noticable for most users.
And ISP's are starting to cap usage now anyway, which makes high bandwidth connections almost a catch 22 and therefore nigh on useless. A 10Mbps with a 75GB cap? It may as well just be an unlimited 2Mbps connection.
Mannnnnn, I need to get out mre
PS. With regards o the Talk Talk offer, is it only available on LLU'ed networks, or is available to all? I am just wondering how they argoing to b able to provide this service for "free" (which is a bit of a con asits not rally free,its bundled, just like NTL do withtheir "free" phone line bundles haha) as BT charge around £12.70 alone just for an L2TP connection on their non-LLU'ed network???