Subject: Errors in topology descriptor

From: Dan Elbert <[email-masked]>
Date: Fri, 13 Apr 2001 09:45:04 -0500

Hi
How are error in the use of the topology descriptor reported ?
For example, let's say that the topology descriptor requires to change some
connection between streams from "isolate" to "bothways" both for some reason
(i.e. lack of resources) the MG is not able to do this. How is this reported
? I don't see topology-related error codes in the spec, or a way to set an
error in a reply to the topology.
Does the failure in executing the topology descriptor affects the execution
of the action to which it belongs ?

Thanks

Dan Elbert
RADVISION

---

From: "Tom-PT Taylor" <[email-masked]>
Date: Tue, 17 Apr 2001 14:24:42 -0400

The error can be reported using the errorDescriptor alternative in the
production:

actionReply          = CtxToken EQUAL ContextID LBRKT 
                       ( errorDescriptor / commandReply ) RBRKT

As usual, the error halts execution of the transaction (not just the action) in
which it is detected.  I would interpret our usual requirement to mean that the
topology should if possible be restored to what it was before processing of the
topology descriptor began.  There is the nasty point that topology can have some
delayed effects (on subsequently added terminations).  I would interpret this to
say that if the problem shows up while processing the Add, it is the Add which
is in error.

Anyway, the error which would be reported would be a generic one like 510 -
Insufficient resources.