All that says is your exchange is is max 10mb,,,, are you 'actually' on and getting 20?.
I can get full 20 because of my distance but I'm on 14Mbps. So yeah the tracker even when it says Max 4Mbps people have posted before showing they have 10Mbps lines so it would be hard to get a exact figure even if Telkom themselves release it it would be hard to trust it.