"Dave" <@.> wrote in message
news:4141622e$0$32057$(E-Mail Removed)
> The ISP I have ordered with is Firenet.
>
> Whats the difference between IPStream and Datastream? Is IPStream
> better for some reason, if so in what way would the user notice the
> difference?
IPStream and DataStream are different ways of transporting the IP traffic
from your exchange to the ISP.
Since I've explained it here in the past I was going to point you to
http://www.adslguide.org.uk/qanda.as...beginners#Q259 but its not a very
clear explanation so..
IPStream is where BT Wholesale carry the IP traffic from your exchange to
the ISP.
Now with IPStream, BT will "bundle" many users in large virtual pipes from
the exchange - so the affects of contention are not noticed that much
(especially as not all the users will be downloading at the same time)
DataStream is where another telco (or your ISP) carry the traffic from the
BT exchange to their core network. This is generally cheaper for the ISP.
This allows ISP's, if they use DataStream to "invent" your own products,
i.e. Bulldog had Primetime ("time of day") products and 50:1 2MB
products -neither of which BT offered
Now the way BT DataStream works is: (Note: I am making these figures up as
an example!)
If there is 1-3 2MB users on the exchange the ISP/telco provides 2MB in
backhaul
If there are 4-5 2MB users they provide 3MB in backhaul etc..
If there are more than 6 users they may provide 4/5MB backhaul from your
exchange to their core network and so on..
Generally this works quite well - as an exchange gets more customers the
ISP/telco increase the capacity that it has to their core network - and is a
lot less than the specified 20/50:1 contention ratio you will have signed up
too... - also remember most customers won't be downloading all the time -
thus there will be spare bandwidth/backhaul for when you do want to
download.
However, if you are unlucky and you only have one or two lines on a BT
DataStream exchange, who try and download at the same time it ruins their
planning/capacity calculations - while you will still get bandwidth etc -
you will not be able to always "max" it out in those cases.. - until the
ISP/other telco increase the capacity and/or there are more customers on the
exchange etc.
However, Firenet will be buying they DataStream service from someone else -
probably Tiscali or Telefonica.. so they will probably have quite a few
customers in "total" on your exchange.
Regards
Sunil