I would soooo love to know the root cause of this "hop 2" latency problem. We've been having similar issues in the Strand and Somerset West: Suddenly, your speed drops quite a bit and browsing (not to mention VOIP and gaming) becoming unresponsive. When you run a traceroute, you see latency of over 100ms (sometimes as much as 1000ms) on hop 2 (the exchange) when it normally sits at around 7 to 15 ms.
Though all this, the Telkom tech support will insist the line is fine (and indeed, when I check my router stats, the sync, SNR and attenuation will all be within normal parameters). I even had a Telkom technician at my premises today to confirm my filter & extensions, as well as the Telkom box inside our complex, are in order. The tech guys working on the DSLAM/IMAX units also insists that there isn't any congestion (with many free ports still available).
I've been having issues like this on and off for over 3 years ... and every time it seems to sort itself out after a few days without any explanation. I would love to know what causes this.