[ih] ARPANET pioneer Jack Haverty says the internet was never finished

[touch at strayalpha.com]

Hi, Jack,
—

> On Mar 5, 2022, at 7:36 PM, Jack Haverty via Internet-history <internet-history at elists.isoc.org> wrote:
> ...
> 
> So, how can you be sure that CDNs necessarily "reduce overall work" by placing CDN servers near a user community?

1. Setup a server
2. Track where your users are (various estimates based on IP address)
3. Put a CDN server closer to your users

That doesn’t reduce server load, but it does reduce user delays. It reduces overall network load, e.g., by dropping the load between the CDN and server. The load at the edge is the same, though. 

> Another experiment I did involved the Internet pathways involving my location, one in Reno nevada, and one in Los Angeles.  Reno is about 50 miles or so East of me.  LA is hundreds of miles south and west of me.
> 
> So a CDN builder might assume that it would be useful to place a CDN cache in Reno as a close-by city.   But experimenting with traceroute indicated that packets from me to Reno actually went west, not east, travelled to LA, bounced around a few nodes in SoCal, and eventually came back north and east to Reno.

CDN operators don’t assume geography correlates to network topology. Note also that traceroute doesn’t always tell you the right thing; some MPLS and SONET paths won’t accept packets with low hop counts (they assume you WANT to see an IP router).

And yes, CDN operators *do* look at all this.

Joe