GENWiki

Network Working Group E. Harslem Request for Comments: 40 J. Heafner

                                                                  RAND
                                                            March 1970

             More Comments on the Forthcoming Protocol

We have recently discussed NWG/RFC Nos. 36 and 39 with Steve Crocker, UCLA. Steve has asked that we elaborate on the errors, queries, and HOST status that were mentioned in NWG/RFC #39.

Please voice your opinions soon in order to affect the forthcoming protocol specifications.

ERROR MESSAGES

   <ERR> <Code> <Command length> <Command in error>

<Code> is an eight-bit field that specifies the error type. The assigned codes are shown below. <Command length> is a 16-bit integer that indicates the length of the <Command in error> in bits. The <Command in error> is the spurious command.

The ranges of <Code> are shown below in hexidecimal.

   00     Unspecified error types
   10-0F  Resource errors
   10-1F  Status errors
   20-2F  Content errors
   30-3F  Unused

Specific values of <Code> are shown below with their meaning.

   <Code> value   Semantics

       00         Unspecified errors.
       01         Request for an invalid resource.
       02         Request for an exhausted resource, try later.
      03-0F       Unused.
       10         Invalid <RSM>, i.e., link connected but unblocked.
       11         Invalid <SPD>.
       12         Invalid <ASG>, i.e., connected but no <RDY>
                    received.

                                                              [Page 1]

   <Code> value   Semantics

       13         Message received on blocked link.
      14-1F       Unused.
       20         Unknown command code.
       21         Message received on unconnected link.
       22         Invalid <RFC>.
       23         Invalid <CLS>.
       24         Invalid <RSM>, i.e., link not connected.
       25         Invalid <FND>.
       26         Invalid <END>.
       27         Invalid <RDY>.
       28         Invalid <ASG>, i.e., not connected.
      29-2F       Unused.
      30-FF       Unused.

QUERIES

   <QRY> <My Socket>

or <RPY> <Your Socket> <Text>

The <QRY> is the query indicated in NWG/RFC #39 and <RPY> is the reply. The format of <Text> is shown below; also refer to NWG/RFC #36, p. 3.

        <relevant connection table entries>

<relevant connection table entries>::=

                                   <relevant connection table entries>
                                   <a relevant connection table entry>
                                   <a relevant connection table entry>

                                     <link> <connection state>
                                     <flow state and buffer control>
                                     <reconnection control state>

                                                              [Page 2]

HOST STATUS

   <NOP>

An NCP may be up, down, pending, etc. When an NCP changes its state to UP it should send a <NOP> to each remote NCP which indicates the NCP is available. The sending NCP can then construct a vector of HOST status from the RFNMs it receives. An NCP receiving a <NOP> can update the availability of the sending NCP in its HOST status vector.

     [ This RFC was put into machine readable form for entry ]
       [ into the online RFC archives by Richard Ames 6/97 ]

                                                              [Page 3]