Network Working Group E. Harslem
Request for Comments: 39
25 March 1970
COMMENTS ON PROTOCOL RE: NWG/RFC #36
We offer the following suggestions to be considered as additions to
the April 28th 1970 protocol grammar specifications.
<ERR> <Code> <Command in error>
It is desirable to include debugging aids in the initial protocol for
checking out Network Control Programs, etc.
There are three classes of errors--content errors, status errors, and
resource allocation or exhaustion. <Code> specifies the class and the
offending member of the class. The command is returned to the
sending NCP for identification and analysis.
Examples of status errors are: messages sent over blocked links and
attempts to unblock an unblocked link. Examples of content errors
are: an invalid RFC complete; a message sent on a link not connected;
closing of an unconnected link; and an attempt to unblock an
unconnected link. Examples of resource errors are: a request for a
non-existent program and connection table overflow, etc. Resource
errors should be followed by a <CLS> in response to the <RFC>.
<QRY> <My Socket> < >
or <QRY> <Your Socket> <Text>
Queries provide an extension to the <ERR> facility as well as limited
error recovery, thus avoiding re-initialization of an NCP.
The first command requests the remote NCP to supply the status of all
connections to the user specified by the user number in <My socket>.
The second is the reply; <Text> contains the connection status
information. If an NCP wants the status of all connections to a
remote HOST, the <My Socket> is zero.