Annex M FAQ

From SonicWiki
Jump to: navigation, search

ADSL2 offers a variety of configuration profiles that allow for changes to the speed and settings of the circuit. The default configuration is Annex A, which provides a maximum speed of 24Mbps download, and 1.4Mbps upload. (We market these speeds at 20Mbps and 1Mbps, as full ADSL2+ speed is rare, limited to very short loops.) Annex M changes the allocation of spectrum, allowing a maximum 3.3Mbps upload speed.

Annex M comes at a cost of reduction in actual download speed for most customer locations, so while you may gain a megabit or so in upload speed, the trade-off in reduction of download speed may be significant. Consider your own bandwidth needs and make a selection based upon your preferences.

For more details on Annex M, see "Wikipedia".

The choice of Annex A or Annex M profile is available to Sonic. Fusion customers at no additional charge.

All current Sonic modems are Annex M compatible.

Most other modems support Annex M by default, but for some older modems you may need to configure your ADSL2 modem to allow an Annex M connection. For assistance please see the forums You may toggle your Fusion service between the upload prioritization (Annex M) or download prioritization (Annex A) profiles. Toggling profiles will cause a service interruption while the modem resynchronizes with our equipment. Your modem must be configured to support Annex M (our rented equipment is) and may take several minutes to sync. If your service does not work after using this tool please dial 611 from your Fusion service and use the self-service tools to switch back.

You can activate Annex M through our member tools

  • Login at


  • On the left we want to go to Labs > Fusion Line Profile


  • To switch to Annex M (Upload profile) Click on the button labeled Upload.