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.
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<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.
<Text>::= <16 bit count of relevant connection table entries>
<relevant connection table entries>
<relevant connection table entries>::=
<relevant connection table entries>
<a relevant connection table entry>
<a relevant connection table entry>
<a relevant connection table entry>::= <local socket> <foreign socket>
<link> <connection state>
<flow state and buffer control>
<reconnection control state>
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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 ]
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