>> As I am on LLU, I thought there aren't pipes and they attain bandwidth differently?
Theres still 'pipes' from the backhaul at the exchange.... and these then join up at other locations to even bigger ones.
Tiscali backhaul doesnt work too much differently than BTw backhaul - the major difference is that the pipes are managed and paid for by tiscali, rather than renting them off BTw. They still go through an ATM backhaul from the exchange, and will join up with a larger town/city, where they are fatter pipes, which will then go on to Tiscali's main PoP.
An LLU backhaul link can use VPs (such as Easynet are assumed to do to separate Sky and UKO), or they can use 'super VPs' like BTw now do for most adslmax MSANs.
Theres a pic from
Inside the exchange which gives a bit more info
but on this you can see the orange fibre back haul links. The LLU ones are at the top - the BTw ones on the bottom shelf
BTw backhaul links are normally 155Mbps for most exchanges.. but the sizes can vary depending on the exchange size and many exchanges may have multiple 155Mbps links.
For LLU its up to the ISP to decide how much they use for eg Be are said to use 100Mbps and increment in 100Mbps stages.
You can still get congestion on LLU both on the exchange backhaul or even on the link from the larger town/city exchange PoP if enough bandwidth isnt provisioned.
An interesting observation, that isnt too clear in that smaller pic, but is obvious in the full size is that on that particular exchange both the AOL and TT MSANs both join at that point onto the same backhaul link.
