RFC 801 (rfc801) - Page 2 of 21
NCP/TCP transition plan
Alternative Format: Original Text Document
RFC 801 November 1981
NCP/TCP Transition Plan
can move into an environment with significantly broader communication
services.
Discussion
----------
The implementation of IP/TCP on several hosts has already been
completed, and the use of some services is underway. It is urgent
that the implementation of of IP/TCP be begun on all other ARPANET
hosts as soon as possible and no later than 1 January 1982 in any
case. Any new host connected to the ARPANET should only implement
IP/TCP and TCP-based services. Several important implementation
issues are discussed in the last section of this memo.
Because all hosts can not be converted to TCP simultaneously, and
some will implement only IP/TCP, it will be necessary to provide
temporarily for communication between NCP-only hosts and TCP-only
hosts. To do this certain hosts which implement both NCP and IP/TCP
will be designated as relay hosts. These relay hosts will support
Telnet, FTP, and Mail services on both NCP and TCP. These relay
services will be provided beginning in November 1981, and will be
fully in place in January 1982.
Initially there will be many NCP-only hosts and a few TCP-only hosts,
and the load on the relay hosts will be relatively light. As time
goes by, and the conversion progresses, there will be more TCP
capable hosts, and fewer NCP-only hosts, plus new TCP-only hosts.
But, presumably most hosts that are now NCP-only will implement
IP/TCP in addition to their NCP and become "dual protocol" hosts.
So, while the load on the relay hosts will rise, it will not be a
substantial portion of the total traffic.
The next section expands on this plan, and the following section
gives some milestones in the transition process. The last section
lists the key documents describing the new protocols and services.
Appendices present scenarios for use of the relay services.
The General Plan
----------------
The goal is to make a complete switch over from the NCP to IP/TCP by
1 January 1983.
It is the task of each host organization to implement IP/TCP for
its own hosts. This implementation task must begin by
1 January 1982.
Postel