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

[Brian E Carpenter]

On 05-Mar-22 05:42, touch--- via Internet-history wrote:
> Minor point...
> 
>> On Mar 4, 2022, at 7:43 AM, Guy Almes via Internet-history <internet-history at elists.isoc.org> wrote:
>>
>> Miles,
>>   The issue is not multicast vs not-multicast.
>>   The issue is doing multicast at the IP / Layer-3 level vs doing multicast at the Application leve
> 
> Multicast needs to include L2 (see RFC3918, Sec 6). Without that, routers would need to do serial copy for every host inside each L2, which is prohibitive (i.e., this is why IGMP is *in addition* to PIM or other IP-level mechanisms).

I think you'd be surprised how much of that actually happens today, under the covers of "Ethernet switches" and WiFi pretending to be Ethernet. We still design protocols on the assumption that a thick yellow cable snakes around the building.

The difficulty arises when you try to make it work at global scope, and Guy's analysis is correct. Somebody asked where MBONE went - it went to Network Operations Hell because it deserved to.

    Brian