Re: Heirarchical error codes

[Rob Earhart <rob@xxxxxxxxxxxxxx>]

On Fri, 19 Mar 1999, Steve Mansour wrote:
> I'm not sure I follow what you're suggesting here. The message subject
> mentions error codes, but your text refers to capabilities.

  Sorry -- I was responding to a message in which the thread had wandered
into protocol revision numbers; I probably should have quoted it, for
context.

> Are you thinking of some sort of CAPABILITY list that the client sends the
> server, and a similar set of capabilities that the server returns based on
> what it received from the client??

  Almost; I'd rather see both simply send capability lists when the
connection is initialized.  For instance, at session startup, one might
see

  C: * CAPABILITY CAP XMLCAL
  S: * CAPABILITY CAP SASL ("KERBEROS_V4" "GSSAPI" "DIGEST-MD5") TLS

(using * instead of a normal tag because these aren't commands; they're
information which doesn't require a reply.) 

  The server probably shouldn't restrict its list based on what it gets
from the client; it's useful to see everything the server's capable of.
After this exchange, both sides know what the other's capable of dealing
with, and can restrict what they speak to the subset of the capabilities
they know about for which the other side has announced support.

  )Rob