On 2007-05-19 11:16:51 +0100, Eusebius said:

posting in uk.telecom.broadband and not here?
Probably wrong group. Must be one discussing ISP's.
Which is the actual issue here.-

Yes. As Above.

So is the question whether to have a BT connection or a cable
connection or a satellite connection? what are the pros and cons of
those? I have had cable before, with Cable and Wireless (cable and
hopeless at the time) so the connection does exist.

There are more subdivisions and technologies than that. I have three
"broadband" connections using different technologies.

The vanilla DSL services offered by virtually every ISP and using BT as
a front end mainly differ by the contention ratio offered but more
importantly by the nature, number and count of upstream connections
that the provider has.

Many of the providers peer at internet exchanges which is relevant for
traffic within the UK. For their international traffic, the smaller
ones buy transit bandwidth from the larger carriers and specialist
transit operators (e.g. Level3). So if most of what you want to do
results from internatiional traffic, it may well be the capacity that
the ISP buys from the transit operators that has the largest influence.

So you have those factors and then the common factor of BT.

Another flavour of DSL service is offered by some ISPs who install
equipment in BT exchanges - known as local loop unbundling (LLU).
Basically here you connect to the provider's network earlier in the
chain rather than going through BT's DSLAMs and other environment
first. This allows some providers to offer more leading edge
services and perhaps to have less conservative bandwidths than are
offered with a BT front end. It may also provide a faster time to fix
than if the ISP has to call BT to fix their part. Whether it results
in better service overall, is less clear. At the end of the day, if
the wire from the exchange breaks BT still gets involved.

I have a DSL service which is about to move to LLU, so I'll see. I
am not expecting there to be a large difference in reliability, and
certainly no perfromance difference.

I have an NTL cable connection at 10Mbits/sec. It is less reliable
in terms of up time (and I measure this) than the DSL connection, but
does deliver what I would expect out of a 10Mbit connection accounting
for the protocol and other overheads etc. However, it is limited in
two significant ways. a) It is highly asymmetric - the upload speed
is around 300-400k and b) it has single dynamic addressing. For
my purposes, this limits its use severely and it is really only
suitable for volume downloads, basic web access and multimedia. To be
fair to them, Virgin Media don't sell it as anything else.

The third connection is a wireless DSL service. This was introduced
by Tele2 in the late 90s before DSL has really become widely available.
It is implemented in a few regions and involves the use of a special
antenna on the roof directed to a base station. It gives me 1Mbit in
both directions, and the technology will go to 2Mbits each way.
Unfortunately, the installation cost for the provider in terms of
equipment was high and so it became impossible to compete with DSL for
home users. The service was most recently acquired by Pipex and as
far as I know, they are not taking new orders for it. Businesses are
being more attracted to DSL services (ADSL and SDSL) anyway.
Ultimately, I expect that there will be Wimax or equivalent as an
alternative.
Nonetheless, this is the most reliable of the three connections.

I have been involved in satellite provisioned internet services in the
past. These have been offered in places where even DSL is not
possible. The downstream data is provided over a satellite
transponder along with TV services and the signal delivered to a
special set top box. The upstream connection is via telephone line
and is thus limited to 56k. This technology is hopeless for anything
interactive because the latency up and down to the satellite is
substantial. Therefore, it was mostly pitched for bulked and batched
downloading.
Because this is not very commercially attractive, I am not sure that
there is anybody left offering it.

If you were thinking of satellite in the sense of Sky's offering, then
this is a DSL service offered following their acquisition of Easynet
who use LLU and BT services.


So it all depends on what you want and what you want to pay - e.g. what
kind of internet access and for what purposes; bundling with video and
TV services and perhaps telephony. There are certainly deals to be
had if you want to buy one of the triple play bundles for example.