3rd Level Ideas and other Noises

On 12 August 70, I met a BBN with representatives from BBN and MIT and

we discussed third llevel protocol.

Dial-up The following proposed dial-up protocol was agreed upon at the

meeting.

The purpose of this piece of protocol is to get a process at one site (hereafter the using site) in contact with the logger at the other site (hereafter the serving site).

To initiate contact, the using process attaches a receive socket US and requests connection to socket 1 in the serving host. The using NCP thus sends

               1            4               4                 1
             ---------------------------------------------------
             |RTS |         US     |        1          |      p|
             ---------------------------------------------------
             |ALL |     P    |    space    |
             -------------------------------

over link 1, where US is the user's receive socket, p is the link, and

space is some nominal spae allocation.

The serving Host may decide to refuse contact, in which case it will respond with the standard CLS. If it accepts contact, however, it will send exactly an even 32 bit number over the connection and close the connection. This even 32 bit number is the name of a receive socket in the serving Host. This socket and the next higher numbered socket are

Network Working Group                                   S. Crocker
Request for Comments #66                                UCLA
                                                        26 August 70

reserved for contact with the user. Thus the serving NCP sends

                 1           4          1
               ----------------------------
               | STR |       1        | US|
               ----------------------------

on link 1, followed by

                          4
                     -----------
                     |    SS   |
                     -----------

on link p. Note that SS must be even.

After sending the server socket number, SS, the NCP sends

            1          4                     4
           -------------------------------------
           |CLS |         1        |        US |
           -------------------------------------
           |STR |      SS+1        |        US |
           ------------------------------------------
           |RTS |      SS          |      US+1 |  q |
           ------------------------------------------
           |ALL | q |       space      |
           -----------------------------

Network Working Group                                   S. Crocker
Request for Comments #66                                UCLA
                                                        26 August 70

The using Host also sets up these connections by sending

           1           4                    4
        ----------------------------------------
        | CLS  |      US         |          1  |
        ----------------------------------------
        | STR  |    US+1         |         SS  |
        --------------------------------------------
        | RTS  |    US           |       SS+1  | r |
        --------------------------------------------

At this point the user should be connected to the logger at the serving

site.

Standard Console

    We next agreed on an initial network standard console: 7-bit ASCII
in 8 bit fields with the eight bit on, transmitted in contiguous
streams.  The speific codes are listed in appendix H of the IMP
Operations manual, BBN report #1877. This seems to work only some
hardship on PDP-10's and be fine for all others.

For break or interrupt many systems use one of the standard

characters; for those which need another kind of signal,

        1       1
       ------------
       |INR  |  r |
       ------------