Subject: Locate search cleanup

From: [email-masked] (Dave Finnie)
Date: Tue, 6 Jun 95 15:24:28 EST

Would someone with DS knowledge please help with the following:

I have been looking at the description in the DS chapter of
the handling of CP-CP session outage during a search procedure.
On page 8-58 (of SC30-3422-3), it indicates that both sides
of a CP-CP session outage send LOCATE(discard) such that the
procedure is cleaned up in both directions.

It is clear (I think :-)) that on the origin CP side, if the
node detecting the outage is waiting for a reply, it can simply 
generate a complete -ve reply LOCATE(discard). This is because
its parent CP is expecting a reply.

However, for the case of the node detecting outage on the
destination CP side, does it send a LOCATE rq or reply ? Also,
how does it use the PCID modifier/search number ? Are they
incremented, or does it use the same subprocedure identifier
as it last received for the search procedure ?
The later of course would require special checking in the
collision detection test (ie a collision is allowed if a
request and locate chain = discard).

The same consideration is required on the origin CP side if
the last thing it sent was a complete reply (keep). Since its
parent is not expecting another reply, it is not clear what
sort of LOCATE (rq/reply, and subprocedure identifier) is
required.

Also, does this cleanup logic apply on a broadcast search as
well as a directed search ?

Assuming answers to the above are that a rq is sent, would
it be normal to send only a LOCATE GDS for the cleanup flow ?
(ie no other GDSs in the search request.)

Many thanks,

Dave