Wednesday, February 25, 2009

UCT's extra bandwidth redux

[from a comment on the last post:]
Of course, SANREN is what's supposed to provide the drastically improved last-mile.
SANReN will eventually provide the core of the new network, and maybe the access leg too. Some Gauteng institutions have access via the fibre ring there and are happy. Many large institutions elsewhere don't have that yet (and are waiting, waiting, waiting) and are unhappy.

However, if the UCT link was increased from ~32 to ~44 Mbps (coincidentally this is like going from an E3 to a DS-3), what's to prevent it from being increased further? Why not a DS-4 (~274 Mbps) :)
BTW, the Google caches are already live. [We don't know for sure that these are GGCs, but see below ] Their effectiveness seems to be improving (presumably their caches are still filling), but they do still use quite a lot of incoming (international) bandwidth.
If these are Google caches (GGCs), I doubt they will have reduced international bandwidth usage much. The local usage would spike because access is so much quicker and easier.
Traceroute (ICMP, rather than UDP) to is also mapping to a TENET IP block, so Google Maps tiles should be served from somewhere local [TENET or GGC or who-knows-what]. [Google Earth] is still mapping to the Google IP addresses overseas. and still map to the Google IP blocks overseas.

So either TENET has some sort of fancy caching and line-rate traffic redirection going on, or Google is doing something interesting.

Hopefully the local build-out will be finished soon.

Tuesday, February 24, 2009

UCT's extra bandwidth

UCT seems to have gotten some extra temporary bandwidth today. Looking at the graphs we see a spike at 14h00 (GMT+2) in the traffic graphs.

Most of the increased bandwidth usage seems to have consumed international traffic and so that international portion of UCT's bandwidth allocation is finally pegged against the limit of 26 Mbps.

Which is interesting.

Because it means that until now, the international traffic has been crowded out by national traffic. Much of which will be to the Akamai cluster at IS, and the upcoming Google Global Caches (GGCs) and local servers.

So more international bandwidth isn't going to help unless the actual "last-mile" to UCT is drastically improved.