[ih] "The First Router" on Jeopardy

[Jack Haverty]

On 11/23/21 9:51 AM, Steve Crocker via Internet-history wrote:
> I wouldn’t expect  TCP packets to be routed differently from UDP packets.

But we *did* expect packets to be routed differently, even though they 
were all IP packets.

That was our purpose in putting the Type-Of-Service and Time-To-Live 
fields in the IP header.  Some packets required more reliable delivery 
but time didn't matter.  A good example is during transfer of a large 
file by FTP.  Other packets required fast delivery, since if they 
arrived too late they weren't useful.  Packet voice is an example.

By setting the TTL and TOS fields appropriately, a host computer could 
advise the IP backbone of routers of what kind of behavior was 
appropriate for that packet.  A packet which is part of a large file 
transfer might be routed over a satellite link, since time wasn't 
critical.   That role was envisioned for the "Wideband Net". However, a 
packet which is part of a conversational voice stream might be routed 
over only terrestrial nets to minimize delay, and if a router along the 
way determined that it would take too long to get to a destination (TTL 
would run down), that router could simply discard it.

This would require a lot of mechanism in the routers, including 
multiple, overlapping, and competing routing algorithms, one for each 
Type Of Service.   At the time (1980ish) the router hardware didn't have 
the capability, and we hadn't figured out how to implement such 
functionality anyway.   But The Plan was to have an Internet which would 
support multiple types of service over the available mix of networks, 
and route packets quite differently even when they were all IP.

Then the Internet went commercial in the mid 80s, and it seems that The 
Plan was lost.

AFAIK, such capabilities never got implemented in IP, although something 
similar must have been done when "multi-protocol routers" appeared in 
the late 80s.  They could simultaneously run several overlapping 
"internets" of different protocols.   When I was involved in operating 
Oracle's corporate intranet in the early 90s, we had IP, Netware, 
Appletalk, OSI, and probably a few others, all running simultaneously.   
I don't recommend it; it was a nightmare to operate.

Jack Haverty