[ebxml-msg] RE: [ebxml-dev] Presence of sequenceNumber element inResponse message.

[David Fischer <david@drummondgroup.com>]

I think your question is, should SequenceNumber be incremented at one end or at
both ends?

SequenceNumber should increment in only one (each) direction.  Our intent was to
assure that messages sent from one business partner arrive in the right order
rather than to sequence an entire conversation, but I don't see this clearly
spelled out.  We may need to add a clarifying statement in the specification.

Looking at the specification, it appears to be confusing.  If SequenceNumber is
incremented "per conversation" which means in both directions since a
conversation goes in both directions, there is a problem.  Suppose CompanyA
sends to CompanyB with sequence number 1.  Then CompanyA sends another message
to CompanyB with sequence number 2 at the same time that CompanyB sends a reply
to CompanyA with sequence number 2.  We have two messages with the same sequence
number.  If the sequence is per-conversation, which 2 is correct?

Am I understanding the question correctly?

I am copying the ebXML-Messaging list to solicit other comments.

Regards,

David Fischer
Drummond Group.

-----Original Message-----
From: Kumar [mailto:kumar@SAMSUNGSDSINDIA.com]
Sent: Wednesday, February 13, 2002 9:21 PM
To: David Fischer
Subject: RE: [ebxml-dev] Presence of sequenceNumber element in Response
message.


David,
My question is
wether sequence number should be incremented at the response end or not.
Party A sends a request To Party B
with following

<MessagaeID>msg00001</MessageID>
<cpaid>cpa0001</cpaid>
<conversationid>con0001</conversationid>
<sequence>4</sequence>

Now the Party B responds to Party A
with following

<MessageID>msg00045</MessageID>
<RefToMessageID>msg00001</RefToMessageID>
<cpaid>cpa001<cpaid>
<conversationid>con0001</conversationid>
<sequence>5</sequence>

------------------------------------------------------?
here goes the doubt, in the response end wether the sequence number
element should be incremented?
wether it remains 4 or should be incremented to 5

regards
kumar

-----Original Message-----
From: David Fischer [mailto:david@drummondgroup.com]
Sent: Wednesday, February 13, 2002 9:50 PM
To: Kumar; ebxml-dev@lists.ebxml.org
Subject: RE: [ebxml-dev] Presence of sequenceNumber element in Response
message.


In both v1.0 and v2.0, ConversationId is a required element on all
messages.
Neither version specifies what its value must be other than it must be
unique
between the too parties.  The concept is of grouping messages which
pertain to
the same thread using this element.  How this is done is not specified
(implementation dependent) and is not used within the confines of the
MSH, with
one exception.

Message Ordering -- SequenceNumber (when present) -- is used within a
Conversation.  ConversationId does not contain (is not an ancestor of)
SequenceNumber.  This is the only time ConversationId is specifically
used in
the specification.  SequenceNumber is not a required element on any
message.
The CPA specifies whether or not SequenceNumber should be present.  If
it is
present, it is incremented within a single Conversation.  A
SequenceNumber of
*1* on two different messages with different ConversationId values is a
valid
construct.  A SequenceNumber of *1* on two different messages with the
same
ConversationId value, is not a valid construct, unless a Reset is
performed
between the messages.

Regards,

David Fischer
Drummond Group.

-----Original Message-----
From: Kumar [mailto:kumar@SAMSUNGSDSINDIA.com]
Sent: Tuesday, February 12, 2002 11:39 PM
To: ebxml-dev@lists.ebxml.org
Subject: [ebxml-dev] Presence of sequenceNumber element in Response
message.


Hi! ebXML folks,
According to ebXML TRP spec "1.0" if the message is reliably sent, it
Must contain the Conversationid element which in turn has a sequence
Number element.
Consider a Situation where two Parties are exchanging some services,
example Party A and Party B

If Party A  initiates the conversation ,
then in the request message following elements appear
MessageID
ConversationID
SequenceNumber

Now the
Party B responds to Party A  , while responding wether the Sequence
Number element must be present or not. If present wether it can be
incremented on the response end.


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