On 19/10/03 10:39 pm, in article RAZJ4GAHSwk$(E-Mail Removed),
"robert w hall" <(E-Mail Removed)> wrote:
[snip]
>>
> But it is not easy, on the basis of these considerations, to see why two
> such similar communities (Stone/Falfield & Slimbridge/Cambridge), 5
> miles apart in a semi-rural area (not the high Cotswolds), one should be
> blessed and the other told it can _never_ make it...
Quite simple - what are apparently "similar communities" are NOT in
telecomms network terms. One can easily be subtended off an existing fibre
ring directly, the other can be two hops remote from the nearest backhaul
node. Just because there is a big exchange are nearby, does not mean that
location is a backhaul node. Big exchanges are for voice - what matters is
the BT Data Network, which does not (always) appear at the same locations.
Have a look at these locations (I don't know them myself) and estimate their
subscriber base .... I suspect they are quite small, so they cannot be used
for subtended fibre routes onward. Also BT have found that the take-up of
capacity in many of their semi-rural nodes has been so poor, that the
probability of a node being subtended off a poor one does not make good
sense.
> It _may_ be down to the 'distance to the nearest node' (since other
> things appear equal) but given that both communities are surrounded on 3
> sides ( the fourth being the Severn) by communities getting adsl, the
> connectivity must be pretty pathological to produce such a result.
Backhaul is certainly a major factor - old rural routes use copper coax
line drivers or old monomode single fibre CMUX systems which cannot be
"pulled out" of existing ducts as the cable would simply disintegrate and
clog it up. So BT have to pull new fibre into a route which (probably) is
very old ductwork, especially if its rural. This will inevitably result in
large amounts of civil works with fairly huge costs to remake the ductwork.
Ergo cost rises dramatically. Plus the minimum costs for as refit of the
exchange - particularly the wiring frame which will need every solder tag
connection replacing with an IDC connection.
> (Moreover both groupings are within sight of a very busy part of the
> M5, which is I suspect, also now used as a telecomms route).
Doubt it - until early/mid 1990's, the Highways agency would not let any
third party use the roadside ductwork for commercial cables. Most of the BT
cable network runs alongside A roads instead. BT generally don¹t use
motorway road and trunk rail routes as they cannot use their code powers
easily.
> But you're right, I don't know...
> the cure's easy - BT, show us the sums!
They could, but all that would achieve is even more furious rows about what
x and y and z should be by people who really aren't qualified (includes me).
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