Subject: Re: LCUP Comment/Question

From: John McMeeking <[email-masked]>
Date: Tue, 1 Jul 2003 14:03:54 -0500

See response (JAM:) below.

John  McMeeking

                      [email-masked]                                                                                   
                      om (Richard V            To:       [email-masked]                                                
                      Huber)                   cc:                                                                        
                      Sent by:                 Subject:  LCUP Comment/Question                                            
                      owner-ietf-ldup@m                                                                                   
                      ail.imc.org                                                                                         

                      07/01/2003 09:18                                                                                    
                      AM                                                                                                  

> Two comments on the LCUP draft:
>
> [CANCEL] [text deleted]
>
> Should the Applicability section (Section 2) say something about the
> expected behavior of LCUP in a replicated environment?  In particular,
> when an LCUP client disconnects and then reconnects, which case do we
> have:
>
>  1. LCUP is defined to work if it reconnects to ANY server holding a
>     replica of the LCUP Context?
>
>  2. LCUP is defined to work only if it connects to the SAME replica
>     that it was previously connected to?
>
>  3. this situation is undefined by LCUP and is determined by the
>     implementation?
>
>  4. something else?

JAM: I think something like 3.  It could work if the LCUP scheme supports
such a thing and all the servers involved support that schema.  I hope that
some implementation will support this. But an implementation isn't /
shouldn't be required to support this.  Maybe some words like:

Use of an LCUP cookie with multiple DSAs in a replicated environment is not
defined by LCUP.  An implementation of LCUP may support continuation of a
LCUP session with another DSA holding a replica of the LCUP context.  In
such cases, the implementation should document the LCUP Scheme used.  In
the absence of knowledge about such support the client should not use a
LCUP cookie with any DSA other than the DSA which issued the original
cookie.

Or something that conveys the notion that it isn't defined by LCUP, but
isn't prohibited.  And leave the door open for vendors (or later standards)
to address this.  And the "document the scheme" part needn't involve
defining an OID and having the client request that format.  I'd hope that
an implementation of LCUP in an replicated environment would support this
with its default LCUP scheme.

> Rick Huber

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From: [email-masked] (Mark C Smith)
Date: Tue, 01 Jul 2003 16:28:06 -0400

John McMeeking wrote:
> ... Maybe some words like:
> 

My too. I thought we discussed this before... LCUP needs to allow 
implementations to support using the same cookie with different 
replicas, and needs to gracefully handle the case where an 
implementation does not support it. For example, if a server does not 
recognize the cookie or can't use the information contained in it, it 
may force a full refresh... but that decision is in the hands of the 
server. I do not think there is any need for the implementation to 
document the cookie scheme or for the client to be careful in this 
case... what am I missing? Server implementations must be able to 
recognize whether a cookie presented by a client is one they sent or a 
compatible cookie (e.g., one sent by a replica).

-- 
Mark Smith
Netscape Directory Product Development
My words are my own, not my employer's.

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From: [email-masked] (Rich Megginson)
Date: Wed, 23 Jul 2003 14:31:54 -0600

>> LCUP cookie with any DSA other than the DSA which issued the original
I think this text should be sufficient.