Re: Using NAT for best-exit routing

[jem () xpat com (John Milburn)]

"Brian Dickson" <briand () teleglobe net> writes:

> The idea is basically this: the web farm provider uses a NAT device
> (or configures NAT on a router) for every peering point with a given peer
> who wants best-exit. Separate address pools (in private address space)
> are used for each such NAT (and distinct such pool sets amongst multiple
> such peer networks). Ingress traffic to the web farm provider has it's
> *source* address NAT'd, and internal routing points return traffic to
> the *same* NAT through which the request traffic came.
> Thus, return (data) traffic is best-exit.

Using a transparant cache for ingress traffic has the same effect as
a NAT device, and scales with the number of concurrent flows.

A cache farm is more expensive to provision and deploy than a simple NAT,
but has the advantage of allowing for logging of source/destURL pairs,
which may be important to some content providers. Caching can also can
be a significant performance improvement in many cases, such as paths
with high latency*BW links or congested long haul circuits.

-jem
     John Milburn                           jem () xpat com
     Director - BoraNet                     jem () bora net
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