What is Annex M?

Annex M extends the capability of ADSL2+ by doubling the number of upstream bits The data rates can be as high as 24 Mbit/s downstream and 3.5 Mbit/s upstream depending on the distance form the telephone exchange to the end user premises.

This increase in upstream is achieved by altering the upstream/downstream frequency split - compared to standard ADSL2+. The main difference is the frequency split has been shifted from 138khz up to 276 khz allowing upstream bandwidth to be increased from 1 Mbit/s to 3.5 Mbit/s, with a corresponding decrease in downstream bandwidth.

There are a number of factors that will have an impact on the speed, but if you are less than 2km away from the local exchange and/or you can receive 12mb or more, then you should be able to benefit from our Annex M service.

In practice we are seeing upstream speeds in the range of 1.4Mb up to approx 2.6Mb. End users close to the exchange should receive 2Mb + and users far away from the exchange may see little or no improvement at all.