Protocols and Data Formats
RFC 80
Document | Type |
RFC - Unknown
(December 1970; No errata)
Obsoleted by RFC 123
Updated by RFC 93
Updates RFC 66
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Authors | |||
Last updated | 2013-03-02 | ||
Stream | Legacy | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | Legacy state | (None) | |
Consensus Boilerplate | Unknown | ||
RFC Editor Note | (None) | ||
IESG | IESG state | RFC 80 (Unknown) | |
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group E. Harslem Request for Comments: 80 J. Heafner NIC: 5608 RAND 1 December 1970 PROTOCOLS AND DATA FORMATS Because of recent discussions of protocols and data formats we issue this note to highlight our current attitudes and investigations in those regards. We first discuss some specific sequences, and then offer some thoughts on two general implementation approaches that will handle these and other specifics. We wish to place emphasis on the _general solutions_ and not on the specifics. INITIAL CONNECTION PROTOCOLS We wish to make two points concerning specific Initial Connection Protocols (IPCs). Firstly, the IPC described in NEW/RFC #66--its generality and a restatement of that ICP. Secondly, a proposal for a variant ICP using basically the same logic as NWG/RFC #66. I. NWG/RFC #66 The only technical error in this IPC is that as diagrammed both the Server and User send ALL messages before the connections are established which is inconsistent with Network Document No. 1. This can easily be remedied as will be shown in the restatement below. In terms of generality, any ICP that is adopted as a standard should apply to more situations than a process calling a logger. That is, some Network service processes that hook directly to a user process, independent of logger action, could perhaps use a standard ICP. Thus, as is shown below, the process name field of the server socket should be a parameter with a value of zero being a special case for loggers. Restatement of NWG/RFC #66 (using the same wording where appropriate) 1. To initiate contact, the using process attaches a receive socket (US) and requests connection to process SERV socket #1 in the serving HOST. (SERV = 0 for ICP to the logger.) As a result the using NCP sends: Harslem, et. al. [Page 1] RFC 80 Protocols and Data Formats 1 December 1970 1 4 3 1 1 +-----+---------------------+---------------+-----+-----+ | RTS | US | SERV | 1 | P | +-----+---------------------+---------------+-----+-----+ over link 1, where P is the receive link. 2. The serving process (SERV) may decide to refuse to the call, in which case it closes the connection. If it accepts the call, the serving process completes the connection (via an INIT system call, hence an STR). 1 3 1 4 +-----+----------------+-----+--------------------+ | STR | SERV | 1 | US | +-----+----------------+-----+--------------------+ 3. When the connection is completed, the user process allocates a nominal amount of space to the connection, resulting in the NCP sending: 1 1 4 +-----+-----+--------------------+ | ALL | P | SPACE | +-----+-----+--------------------+ where SPACE is the amount. 4. The serving process then selects the socket pair it wishes to assign this user. It sends exactly an even 32 bit number over the connection. This even 32 bit number (SS) is the receive socket in the serving HOST. This socket and the next higher numbered socket are reserved for the using process. 5. It then closes the connection. The serving NCP sends (step 4): 4 +---------------------+ | SS | +---------------------+ on link P, and (step 5): Harslem, et. al. [Page 2] RFC 80 Protocols and Data Formats 1 December 1970 1 3 1 4 +-----+----------------+-----+--------------------+ | CLS | SERV | 1 | US | +-----+----------------+-----+--------------------+ on the control link (which is echoed by the using NCP). 6. Now that both server and user are aware of the remote socket pair for the duplex connection, <STR, RTS>s can be exchanged. _Sever sends User_ 1 4 4 +-----+--------------------+--------------------+ | STR | SS + 1 | US | +-----+--------------------+--------------------+---+ | RTS | SS | SS + 1 | Q | +-----+--------------------+--------------------+---+Show full document text