Last updated on 8 Sept 2005

Telkom ADSL ping times

On the 22nd of February 2005, Telkom introduced two new changes to their ADSL network (at least in the Centurion area). First off, the sync rate was changed to 640/384 (down from 2048/512). Secondly they changed the path mode from "Fast" to "Interleaved", causing latency to the first hop to jump from 16ms to 54ms.

Update: On the 16th of March 2005 at 10pm, Telkom reverted back to their previous configurations regarding sync rate and path mode. We're back on 2048/512 and ping times have dramatically improved with first-hop ping times in the region of 10.5ms.

Update: On the 29th of March 2005 at 1pm, Telkom again changed the DSLAM settings. This time they kept Fast Path mode, but set the sync rate back to a slower 640/384. At least the latency is still decent at around 12ms to the first hop.

Telkom peering

Telkom has also stopped upgrading their peering links to other ISPs and content providers. It is very clear from the sample I took for 28th of Feb 2005 that the Telkom peering link to I.S. it totally congested. Comparative plots for UUnet and UUnet International are also given.

Note that the ping times jump from 57ms to just under 200ms during the day as the peering link to I.S. gets congested. It returns to "normal" when the day-time traffic has abated. This in itself is very suspicious - I would expect ping times to vary wildly, not follow the rigid increase that we see in the graph.

Note that peering to UUNet in ZA and UUNet in the US is still fine in the previous graph, but it gets worse in the following graph:

Not that the peering problem towards I.S. has stayed more or less the same, but that peering towards UUNet ZA has started to suffer as well. Also note that international ping times have also gotten worse towards ns.uu.net.

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