An E1 line - how does it work?

We've been told that our current dual bonded ADSL solution is being changed to an E1 line. Apparently they are going to get rid of our two ISDN lines and the two ADSL lines and replace all of that with a single E1 connection.

I'm curious what kind of technology is going to be used (it sure ain't going to be fibre, lol). Our office is in a converted barn about 4km from the exchange. Our ADSL lines currently have attenuations of around 54db and are moderately stable (some days rock solid, other days one or two drops an hour).

So what's involved in providing a 2Mb/s bidirectional Ethernet link over that kind of distance? Bonded copper pairs? We queried reliability since it's going to have to carry all our comms traffic and we've been assured that it will be as stable and reliable as a telephone line. Any sign of instability is to be treated as a fault and will be immediately rectified.

Could be bonded copper / EFM. Another thought is that if there's a cabinet nearby that might have fibre to it or has ducting with room they'll blow fibre and run SHDSL from there.

Those are the two that come to mind immediately.

E1 is 2Mb

More about E1

In reply to a post by somerset:

E1 is 2Mb

Not sure I get your point?

In reply to a post by Ignitionnet:

Could be bonded copper / EFM. Another thought is that if there's a cabinet nearby that might have fibre to it or has ducting with room they'll blow fibre and run SHDSL from there.

Those are the two that come to mind immediately.

There's a cabinet in the village but we've also been told that one of the advantages is that it's relatively cheap. Supposedly all things considered (including putting us on their world-wide VOiP system) means they come out almost even.

Simplistically, an E1 is a 2Mb Private Circuit, which can be delivered via fibre, but more usually via copper.
Interface presentation is usually G.703, but can also be X.21. Transmission technology can be SDH, but is more likely to be PDH.
Usually very reliable and generally supported by high SLA's, giving a response time for reported faults of 4-5 hours, covered 24x7x365.

In reply to a post by Ignitionnet:

In reply to a post by somerset:

E1 is 2Mb

Not sure I get your point?

The speed of an E1 link is 2Mb.

In reply to a post by somerset:

The speed of an E1 link is 2Mb.

Yes, I know, and I still don't get your point.

In reply to a post by panda:

Simplistically, an E1 is a 2Mb Private Circuit, which can be delivered via fibre, but more usually via copper.
Interface presentation is usually G.703, but can also be X.21. Transmission technology can be SDH, but is more likely to be PDH.
Usually very reliable and generally supported by high SLA's, giving a response time for reported faults of 4-5 hours, covered 24x7x365.

Yes I know this and am quite familiar with them, have assisted in commissioning a few. Over the kind of distance the OP mentioned though, with DSL circuits indicating a loop length of >4km, doesn't this seem a bit of a stretch for 2 pairs? Without a line extension / regeneration E1s max out around 3km.

E1s are often delivered via SHDSL and HDSL. The cable companies come to mind immediately as two who delivered this way, fibre to cabinet then SHDSL or HDSL if multiple pairs are needed.

The point of running with EFM is to supply resiliency and remove the need for a repeater. Even over that range they can rack some pairs up to deliver 2Mbps reliably using SHDSL.bis.