^^ So a profile of 17a can get 120/40 from 80/20 profile 8b. So, BT can do 120/40 next year if they want?

BT use 17a now, they have never sold 80/20 on 8b.

In reply to a post by Ignitionnet:

BT use 17a now, they have never sold 80/20 on 8b.

Right, so BT use 17a now. Mean they can add 120/40 if they wish to challenge virgin media 152/12?

Edited by adslmax (Mon 11-Nov-13 21:24:35)

In reply to a post by adslmax:

^^ So a profile of 17a can get 120/40 from 80/20 profile 8b. So, BT can do 120/40 next year if they want?

The Profile 17a graph in that story shows 120/40 is achievable at no more than 500 feet (so, just over 150 metres) from the cabinet - and this likely assumes the local infrastructure is in ideal condition and there is minimal crosstalk (or that vectoring is working ideally).

The current Openreach FTTC modems have 100 Mbit/s Ethernet ports, so will struggle to manage more than about 95 Mbit/s actual throughput.

As Ignitionnet has said, a service can only be marketed as offering a certain speed if more than 10% of potential customers can receive that speed. We may see a faster offering once vectoring is rolled out, but it is unlikely to offer much more than 80/20 in most cases.

I'd rather stick with my current 80/20 fast path than have a slight increase in speed with interleaving.

David_W what do u think of virgin media 152/12? good or very bad! I think it pretty poor to be honest. They should have gone for 200/20 instead.

Are they actually spending all this extra money investing in the network or are they just changing the numbers in our modems and collecting the profit?

To be honest even another 6.7% rise would still be £8 a month cheaper than getting a phone line and a fibre package. But I would imagine that prices for fibre packages will tend to come down in future and the gap will close? Especially if Virgin continue the way they are going.

Not until they deploy G.Vector widely. Hardly anyone would get close to 120Mb/40Mb and it's required that 10% of people can reach a speed before it can be advertised.

BT have never and will never compete with Virgin Media on speed.

In reply to a post by adslmax:

David_W what do u think of virgin media 152/12? good or very bad! I think it pretty poor to be honest. They should have gone for 200/20 instead.

You have to design services with the underlying technology in mind. FTTC is uncontended back to the cabinet. Cable uses shared channels.

With shared channels, traffic can be managed to optimise the use of the downstream, as only one piece of equipment is transmitting on the downstream. On the upstream, multiple talkers need to share the same resource, with varying strategies used depending on the technology. If I remember correctly, the DOCSIS cable modem technology involves each modem being told when to transmit, which allows the system to optimise the upstream throughput.

I'm not familiar with the precise configuration used by Virgin Media at present, but EuroDOCSIS 3.0 with 8 downstream channels and 4 upstream channels has a usable throughput of 400/108 Mbit/s across all the users of the channel group. Exhausting the available upstream bandwidth has a devastating effect on all customers on that channel group, so even allowing for contention, you have to be cautious about the upstream cap.

Mine is currently configured with 8 downstream and 2 upstream.

Still waiting for a scheduled rollout of the upload upgrades to match the 10% claim.

I only know of some (perhaps now most) 120mb customers having 12mb uploads.

60mb customers stuck on 3mbps upload and 30mbps on 1.5mbps.

Double my upload speeds please virgin, then lets talk about download again.