said by mlerner:
Telus is doing 50/10 using line bonding and with much of their footprint covered with remotes. Bell doesn't want to use multiple pairs as they are too cheap to string up more remotes and line cards. Remember how long it took them to get from 5 megs to 10+?
This is actually done primarily with single-line VDSL2 17A (and some 8B) and with a port profile that is 76mbps down, 12mbps up.
Bonding is only available in limited areas for now, as the install cost is much higher and we don't want to burn pairs and ports.