Title:
Comments in-line...
Regards,
David Fischer
Drummond Group.
-----Original Message-----
From: Burdett, David
[mailto:]
Sent: Monday, July 30, 2001
2:30 PM
To: 'David Fischer'
Cc: ebXML
Msg
Subject: RE: T2 Reliable Messaging w/o CPA or
VIA...
David
Let's take of these in turn ...
mshTimeAccuracy
>>>This is
the accuracy to which a recipient of a message claims to keep their internal
system clocks. This should probably be part of a CPP and not vary from message
to message therefore it does not need to be in the MessageHeader
[David
Fischer] Agreed, but what if there is no CPP? I'm not sure why this
is necessary.
reliableMessagingMethod
>>>This needs to be in the Via since it can vary on each hop
of a multi-hop message. I suppose though that, if you are not doing multi-hop
then it forces use of the Via element. I think we could either:
1. Put
reliableMessagingMethod in the main MessageHeader with the copy in the
Via element over-riding it, or
2. Change the definition of the Via element
to suggest that it to be used when there is no
intermediary
Thoughts?
[David Fischer] Option 1. Let's not muddle the
Via. What if the MessageHeader reliability is higher (I assume "ebXML"
is higher than "Transport"). Should an intermediate hop have a lower
reliability than the end-to-end? Or do we care since it is a "black
box"? Methods "ebXML" and "Transport" do not seem to be
defined.
ackRequested
>>>This is
in Via for the same reason as for reliableMessagingMethod - it can vary from
hop-to-hop
[David
Fischer] How do we accomplish single-hop Reliable Messaging? We
need to be able to request an Acknowledgement without the Via. We could
say that a DeliveryReceipt is equivalent. This means the receiver will
have to process DeliveryReceipt as an Acknowledgement (set the Acknowledgement
flag in the message database when a DeliveryReceipt is received and do all the
other Reliable Messaging tasks equivalently--sequencing, persistent store
etc.) which would be OK. Acknowledgement would then NEVER be used
except in conjunction with VIA. This would uncomplicate Reliable
Messaging but chapter 10 would have to be significantly re-written
(replace/combine Acknowledgement with DeliveryReceipt in lots of
places). What about 10.3.3 which specifies that an Acknowledgement MUST
be sent. How is the receiving MSH to know if this is single-hop or
multi-hop (whether to send Acknowledgement or DeliveryReceipt) by
the presence of a VIA element? I don't think the Via actually get
passed to the end-point since SOAP-Actor=next gets consumed in-route.
How does the last hop/end know to send an Acknowledgement w/o the VIA?
retries &
retryInterval
>>>These are both parameters that apply to
the sender of a message and over which the receiver of message can have no
effective control. There is therefore no need for them to be in the header.
They should however be in the CPP for the sender
[David Fischer] What
if there is no CPP? Is there never a need for the receiver to know how
often and how many times the message will be resent? Maybe not. In
my experience, the receiver usually ends up calling the sender on the phone
for this info. This is not needed very often -- only to troubleshoot
problems. I have seen many cases of "why did you send
that message to me three times?" when the answer was related to
retries. Agreed.
persistDuration
>>>PersistDuration only applies to the recipient of a message
as it specifies the minimum time the recipient will keep a message. The sender
cannot (should not?) control this, therefore there is no need for it to go in
the header.
[David Fischer] Agreed. How is the sender to
know? Should this be in the DeliveryReceipt? While this should be
agreed to in the CPA, we cannot assume the existence of a CPA. I am
still on the fence about whether there will be more implementations with or
without a CPP/CPA. Could go either way depending upon the number of SME
implementations vs. LE.
I'd
appreciate your thoughts.
David
-----Original Message-----
From: David Fischer
[mailto:]
Sent: Monday, July 23, 2001 7:07
PM
To: Burdett, David
Cc: ebXML Msg
Subject:
T2 Reliable Messaging w/o CPA or VIA...
Section 10.2 (line 1695)
says:
This
parameter information can be specified in the CPA or in the MessageHeader
But I can't find anywhere in
the MessageHeader to set the following parameters:
mshTimeAccuracy
reliableMessagingMethod
ackRequested
retries
retryInterval
persistDuration
This seems like a formidable problem
when doing reliable messaging (ackRequested) without an intermediary
(no Via). If we put this information back in the MessageHeader,
why is it also in the Via? This was in the MessageHeader in v0.91 but
it was taken out... probably shouldn't have been.
Regards,
David Fischer
Drummond
Group.
