Re: Chaining vs Referrals ?? -Reply

D.W.Chadwick@iti.salford.ac.uk Wed, 28 February 1996 23:06 UTC

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From: D.W.Chadwick@iti.salford.ac.uk
Date: 28 Feb 96 16:43
To: osi-ds@cs.ucl.ac.uk
Subject: Re: Chaining vs Referrals ?? -Reply
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Date: Sat, 24 Feb 1996 12:20:14 -0800 
From: Ed_Reed@novell.com (Ed Reed)
To: osi-ds@cs.ucl.ac.uk, LIVINGSTON-C@smtpgw.nctsw.navy.mil 
Subject: Chaining vs Referrals ?? -Reply
     
     
Technically, the chaining approach is required when full DUA-DSA 
connectivity is not possible, either because there are multiple protocols 
and the DUAs don't support them all, or because of intentional 
discontinuities, such as Firewalls.
     ----------------------------
     Ed
     
     You might be interested to know that we are building an X.500 firewall 
     at Salford (a proxy server - we actually call it a Guardian DSA), and 
     one of its features will be to take a DAP request from a DUA on the 
     secure network and forward it as another DAP request, to a DSA on the 
     insecure network (the latter DSA may for example have returned a 
     "returnToDUA referral") So this is another variant of the chaining 
     approach, only this time the Guardian DSA is acting as a proxy DUA.
     
     David