RFC 146 (rfc146) - Page 2 of 6
Views on issues relevant to data sharing on computer networks
Alternative Format: Original Text Document
Our Views
One approach to achieving data sharing on the ARPA Network can
be thought of as having three stages, which roughly correspond to
the modes of use or operation. Within each stage are various levels
of development required to get to the next stage. This development
is not necessarily sequential. A description of the three stages
follows.
Stage 1: Data handling services are provided at various Hosts.
The user talks directly to the serving Host (via TELNET
or by addressing a known socket) to explicitly access
the service. This mode of operation corresponds to
Bhushan's category of "direct" usage (RFC #114). The
data services provided by the serving Host range from
simple ones, such as White's file transfer system (RFC #122)
to sophisticated systems such as the CCA's data machine
(NIC 5791 and 6706).
Stage 2: The user has access to an intermediate process or data
control facility* that routes his requests for a particular
data service to the serving system. The user must explicitly
identify the data services to the used. This mode of
operation corresponds to Bhushan's category of "indirect"
access. The data control facility provides the necessary
control commands, data transformations, and accessing
methods. A single request would include the use of several
interacting services. For example, Heafner's Data
Reconfiguration Service (RFC #l38) could be used in
conjunction with the use of CCA's data machine.
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*The data control facility is not necessarily located at his local
Host. Such a facility may exist on from one to all Host (i.e.,
ranging from centralized to completely distributed).