[ih] IP/TCP to TCP/IP

[Craig Milo Rogers]

>Everyone now knows the suite of Internet protocols as TCP/IP, but a few
>of the early Internet documents I've seen have them documented as
>IP/TCP.  Did they purposely get reversed?  If so, why?  Was it just a
>matter of personal preference and TCP/IP won out?

	I just tripped over the loose hanging threads of my
memory on this one recently.  Here's what I remember, based on a conversation
with Jon Postel about 20 years ago:

1)	Originally, TCP and IP were a single protocol level, called
	TCP.

2)	Internet developers named protocol stacks starting (left-to-right)
	at the lowest protocol level: IP/TCP, IP/TCP/FTP, IP/UDP,
	IP/UDP/TFTP, etc., since the processing of incoming packets
	proceeds from the lowest level to the highest level in most
	implementations.

	It's interesting to note that the processing of incoming packets
	is considered more important than the construction of outgoing
	paclets.

3)	"Press" articles put the TCP first, because the TCP name was more
	recognizable:  TCP/IP, UDP/IP

	It's worth noting that, given that we read from left to right, and
	given that "/" can be interpreted as "over", such as in fractions,
	"TCP/IP" reads "TCP over IP", which is reasonably mnemonic.


	By and large, "TCP/IP" won out in general usage.  However,
technical projects, such as Active Networking, still represents
protocol stacks from the bottom up, such as IF/IPv4/TCP ("IF" being the
physical interface layer).

					Craig Milo Rogers