Can a presentation context be different for the reply message?

[Victor Derks]

I was not able to find a statement in PS 3.7 or in PS 3.8 that allows
or forbids that an association acceptor sends its reply with a
different presentation context (with the same abstract syntax name).

Example: During the association build up phase the requestor proposes
2 presentation contexts: ID 1: Verification Service with implicit
little endian and ID 3: Verification Service with explicit little
endian. The association acceptor accepts both.

The requestor sends a C-ECHO request using presentation context ID 1
and the acceptor sends a reply using presentation context ID 3.

What should the requestor do? accept the reply or flag it as a
violation?

[David Clunie]

Yes.

The two messages (C-ECHO request and response) are independent
P-DATA requests from the Upper Layer Service's perspective.

Any accepted presentation context can be used for any P-DATA
request on that association, and there is NO requirement that
the presentation context be the same for the reply and response..

The requestor should accept the reply (otherwise it should not
have offered that presentation context in the first place).

David

[Victor Derks]

Thanks David for the clarification.

I assumes that this even holds when the other presentation context has
a different abstract syntax: A C-ECHO response can be send on a
presentation context that was negotiated with a C-STORE abstract
syntax.

Victor

[David Clunie]

No, of course not.

You can only send the response on a presentation context that
is appropriate for the abstract syntax, since otherwise the
response would not be valid.

David