Sadly the BT Homehub v4 doesn't grant access to any line stats except for the down/up sync speed.
Given my speed tests are consistently around 3.4Mb down I'm fairly sure the IP profile is set at 3.5Mb.
However, it seems to have settled itself now and the upload is synced at 448.
It's been difficult to get a good idea what my actual upload speed has been since Christmas, because I started using Google Drive and the computer in the living room spent almost 3 months slowly uploading 13 years worth of digital photos.
