Re: Heirarchical error codes

["Frank Dawson" <fdawson@xxxxxxxxxxxxx>]

On Thursday, March 18, 1999 8:29 PM, Doug Royer wrote in part:

>> >Doug and Frank
>> >responded that that wouldn't happen, because all error codes have to be
>> >registered; there aren't any X- errors.  The point, however, is that
>> >registration doesn't help when you're talking to an old client that
>> >doesn't know the new error codes.
>>
>> So, you think that we should support "older" CUAs connecting to "newer"
CSs?
>> Isn't this fraught with problems?
>>
>> At the time you connect, a CUA will get the CAP version number of the CS,
>> right? So, the CAP CUA will begin by knowing that it is talking to an "up
>> version" CS. Won't this key the CUA that it may get different
REQUEST-STATUS
>> codes?
>
>I think this is a flaw with IMAP and we should not do this.
>The only way that most customers would find this is when all of a
>sudden - their CUA stopped working?
>


By this same logic, an arbitrary CUA should be able to speak LDAP or IMAP.

If a CUA connects to a CS and doesn't find the server-side protocol
environment that it is compatible with, then this is a fatal exception and
the sessions shouldn't continue.

We are taking this discussion of "ol' CUA talkin' to newer CS" too far. I
think that we need to fall back on KISS design philosophy and say no more
than I have propoposed above.

- - Frank