RFC 98 (rfc98) - Page 2 of 10

Logger Protocol Proposal

RFC 98                  Logger Protcol Proposal                 Feb 1971


agreement should  be  reached  as  soon  as  possible  on  some  general
protocol.  This is all the more desirable in view of the fact that it is
quite likely that  certain  points  which  should  be  covered  in  this
protocol  will only become apparent during the course of implementation;
therefore, the sooner a common basis for implementation can be  reached,
the sooner a more rigorous protocol can be enunciated.

        Before turning to 1) a discussion of the points  with  which  to
decide  the  protocol should deal, and 2) specifications for the current
state  of  the  protocolm  we  feel  that  we  should  acknowledge   the
consideration  that  a  case could be made for avoidingthe difficulty of
generating a Logger Protocol by simply  declaring  that  each  host  may
specify  its  own, perhaps unique, preferences for being approached over
the Network. Although such a course is certainly possible, it  does  not
seem  to  us  to  be desirable. One reason for avoiding such a course is
simply that following  it  hamper  general  Network  progress,  in  that
adressing  the task of interfacing with some 20 systems is bound to more
time-consuming than to interface with "one"  system,  even  though  each
indivudual one of the former, multiple interfaces might be in some sense
simpler than the latter, single interface. Another consideration is less
pragmatic,  but  nonetheless  important:  agreement on a common protocol
would tend to foster a sense of Network "community", which would tend to
be  fragmented  by  the  local option route. After all, the Host-to-Host
Protocol could have been handled on a per-host basis as well; assumedly,
one  reason  why it has not had something to do with similar, admittedly
abstract considerations.

Context

   Structurally, the mechanism serving to login a user over the  Network
consists  of  two  parts,  one  part at the using host, the other at the
serving host. The using or local host is the  one  to  which  the  users
typewriter is directly connected; it contains a modulewhich channels and
transforms  communications  between  the  Network  connection  and   the
typewriter. The serving or foreign host provides the service to be used;
it contains programming that adapts the logger and command system to use
through the Network rather than a local typewriter.

      There are three different phases to a login through the network.

      1. During the connection phase the users console is connected to
         the serving logger through the network. This is, of course,
         the most important phase from the protocol viewpoint.

      2. The second or dialog phase consists of a sequence of exchange
         between the user and the logger that serves to identify the
         user and verify his right to use the system. In some hosts,
         this phase may be minimal or non-existent.