On Wed, 9 Jun 2004, Juha Saarinen wrote:
Joe Abley wrote:
Akamai has nodes in New Zealand, though. Or are you suggesting that NZ ISPs routinely cache domestic content as well as content from overseas?
Well, that's what I'm curious about. Do ISPs here "uncache" Akamaised content coming from the local nodes?
I can't speak for everyone, however our caches only operate facing our international transit circuits, and domestic and "local" (eg. Akamai deployment) gets ignored. Akamai does encourage (well, somewhat) ISPs to cache traffic towards Akamai if neccessary, and in general it is quite cachable, being images etc in a lot of cases. I have heard of one ISP who, due to their network architecture, is looking to deploy some rather large Cache Engines in order to cache both domestic and international, as they can't feasibly separate the two.
From our perspective, the caches serve to purposes:
1. Bandwidth reduction - we really do see some quite significant savings on HTTP bandwidth with the caches, and if we take them out we can watch the international load climb substantially. 2. Latency reduction - it makes the browsing experience feel nicer as it's served more locally. We don't really find we have too many issues with them that require helpdesk intervention - on the rare occasion, it's usually caused by the server not sending correct header information, or not responding to IMS requests properly (Hi, IIS4.0 and some releases of 5.0). Ofcourse, when you have caches in your critical path that account for 60-70% of traffic across 2 parallel circuits that are using CEF per-flow load balancing, you see some amusing traffic patterns. aj -- Network Operations || noc. +64.9.915.1825 Maxnet || cell. +64.21.639.706