Port numbers and traffic data

[Ian Batten]

On 20 Apr 2008, at 19:24, Roland Perry wrote:
>>
>> I suspect that that's largely because of BTs comparatively high  
>> charges for passing bits to ADSL customers.
>
> For those who use BT backhaul, it's a large part of the cost, I  
> understand.

There are plenty of ISPs for whom that excuse doesn't wash.  It's  
Easynet, I think, who have the canalside fibres that were laid by  
Fibrenet and then ended up in the hands of Marconi.  The ISPs who are  
the IP arm of OLOs by and large have their own fibres into ATEs if  
nothing else.  And several of the MOLOs have their own fibre as well.   
If the fibres in a reasonable state it's obviously trivial to get  
10Gbps through it (any reputable ethernet switch vendor will sell you  
10Gbps interfaces and long-haul gbics are a few hundred quid) and in  
reality you can put perhaps 100 lambdas at 1Gbps each through it for  
sensible-ish money with modern WDM kit.   Switching those lambdas  
isn't cheap, of course.

ian