BT Exchange failure points

In the company I work for we use BT MPLS wan lines and then have BT adsl lines as a backup.

If both of these services are being served from the same exchange, what parts are common that may then have an issue if something breaks. I am just attempting to understand what the risk is using primary and backup lines from the same exchange

I know some of this is good, some is bad, but for one site its what it is:

* Using 2 cisco routers. One for the Primary and one for the secondary line into site
* Both housed in the same computer room, in the same rack.
* Looks to use different connection points on the wall
* Using the same under road duct for the cables into the site
* Street to the exchange same???
* In the exchange (black hole) what's common and what is not? The question

air con, power supply to exchange and physical ducting to / from exchange likely to be same. In the same physical building, so same risk of terrorist attack / aircrash etc if you're looking that wide at scenario planning.

Route from you to exchange likely to be same too.

Suggest you look at your building as well. Do you have a UPS and generator, separate supplies to each router etc.?

There's also likely to be some crossover in the backhaul back from the exhange - while will be quite different, it may be going over the same physical fibre at the end of the day, or going through the same routers at some point.

Depending on your availability, you should look at adding one or more of these to the mix:

LLU fibre broadband, which would be more likely to have a different backhaul arrangement (though far from guaranteed)
Virgin Media cable
3G/LTE mobile broadband

In the event of a total failure of BT stuff at your exchange, the latter two are likely to provide more redundancy.

I did the physical walk around with the onsite expert today. Its not very separate. Well its just not separate at all for most things on site. A bit of a re-gig needed....

thank you, will look at these options...

so the physical infrastructure is the same (building, power, air-con, street ducting) and possibly some of the back hall from the exchange to the larger 'cloud'.

Do all BT exchanges have a UPS / generator, or do we not know this type of information at all... so its pot luck.

Battery backup, most have standby generators but not all.

Are they still running the generators in the winter and selling it into the grid?

Remember that being the bane of my life working for an OLO - slightly dodgy rectifiers / UPS so when the exchange cut from mains to generator all the colo'd DSLAMs would bounce, then again when the generator run was done.

If the second "backup" line only comes in to operation when the first fails, have you tested such "failure"?

We also had a two line set-up, one working; and the second only supposed to come in to operation automatically if the first failed.

I requested that this be tested - refused.

So one week-end, I "pulled the plug" on the first line - catastrophe!

It came to light that the other end, at the control centre, had not been set up properly.