Update: Please note that as of firmware version 1.1.19(004), Annex M services should be selected automatically. This process should therefore no longer be required.
Some customers have reported that the SRP500 will not train to ADSL2+ Annex M services in some cases.
If you find this to be the case, please try the following:
For an SRP527
For an SRP547
Follow the same steps as above. To select DSL Modulation, follow the WAN1 link from the WAN Interface List.