HOST (Sigma 7) <--|/|--> Outside world
   Users                                     |/|
    |                                        |/|
    |                                        |/|   Special  Standard
    V                                        |/|      |       |
         +--------------+   +------------+   |/|      V   |   V
    o----|              |   |            |   |/|   +------+------+
         |   Output     |-->|   Output   |-->|/|-->|      |      |-->IMP
    . . .|              |   |            |   |/|   |             |
         |              |   |            |   |/|   |      |      |
    o----| (Multiplex)  |   |            |   |/|   |             |
         |_ _ _ _ _ _ _ |   |_ _ _ _ _ _ |   |/|   | _ _ _| _ _ _|
    o----|              |   |            |   |/|   |      |      |
         |   Input      |<--|    Input   |<--|/|<--|             |<--IMP
    . . .|              |   |            |   |/|   |      |      |
         |              |   |            |   |/|   |             |
    o----|(Distribution)|   |            |   |/|   +------|------+
         |              |   |            |   |/|       HARDWARE
         +--------------+   +------------+   |/|       Interface
             NETWORK          HANDLER        |/|
             Program          Program        |/|
                                             |/|    (Fig. 1)
















 
RFC 7                      Host-IMP Interface                   May 1969


                                                   +------------------+
                                                   | | |              |
                                                   | | | interface    |
                                                   | | |              |
                                                   |                  |
                                                   | ====> Data       |
                                                   |                  |
                                                   | ----- Logical    |
                                                   |       information|
                                                   +------------------+

                      + - - - - - - - - - - - - - -+
                      |                            |
                              interface table
                      |        +----------+        |               | |
        | |              +---->|          |<----+                  | |
        | |           |  |     +----------+     |  |   interrupt   | |
        | |           ^  |                      |     +----<-------| |
        | |           |  |    +-          -+    |  |  |            | |
        | |           |  V    |  _________ |    V  V  V            | |
   o----| |-+  +---------+-+  | |         ||  +-+--+--+---+        | |
        | |  \ |+---------+|  | |_________||  |+---------+|        | |
        | |   \||         ||  |            |  ||         ||        | |
        | |    +|         ||  | - - - - - -|  ||         ||        | |
        | |    ||         ||  |            |  ||         ||        | |
    - - - - - -|| NETWORK ||=>-  _________ -=>|| HANDLER ||=======>| |
        | |    +| Progr.  ||  | |         ||  || Progr.  ||        | |
        | |   /||         ||  | |_________||  ||         ||        | |
        | |  / |+---------+|  |            |  |+---------+|        | |
   o----| |-+  +-----------+  |  _________ |  +----+------+        | |
   ^    | |                   | |         ||       |               | |
   |    | |                   | |_________||       +--->---------->| |
   |     ^                    +-    ^     -+         Commands      | |
   Users |                          |                              | |
         |                    Pool of buffers                      | |
       User's                                                       ^
      Interface                                                     |
                                                              Hardware
                                                             Interface

                           (Fig. 2)




         [ This RFC was put into machine readable form for entry ]
   [ into the online RFC archives by Bob German & Lorrie Shiota 1/02 ]