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

[Dave Crocker]

> The small amount of multicast address space really isn't a problem in
> practice.  For any successful, scalable multicast deployment, you'll end up
> with source-rooted trees and the forwarding state in the routers are (S,G)
> tuples.


Broadly, for anything like TOS or multicast, there are two different 
sets of issues, either of which can easily create showstoppers.

First is, of course, the mechanics.  What is the functional design? 
What is the basis for believing it will satisfy real-world needs?  How 
robust will it be?  How easy to operate?  Etc.

Second is gaining adoption across a very large range of entirely 
independent operators.  What are their immediate, compelling business 
incentives?

As we keep seeing, getting adoption of anything across an Internet 
infrastructure service, is more than a little challenging.

Cable TV's multicast is done within the span of a single administrative 
control.  And it's a relatively stable, constrained set of traffic. 
Generic Internet multicast is multiple administrations, with highly 
variable sets of traffic, across many administrations.  Very, very 
different game.

d/

-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net