Experimental TESTxx header usage.

[Kevin Hawkins]

Something (**NEW**) to play with to help us move forward on some of the
high
level policy issues and any needs to support them 'within' the xAP 1.2
spec.

The xAP specification committee agreed in the v1.2 spec release,
(although we did not publish it), to allow the inclusion of TEST headers
within xAP messages as a way of trialling suggested features. It is
perfectly permissible to use, for your own purposes - (see below) the name
value pairs Test00 to Test09 in the HEADER . Please note that the spec for
xAP v1.2 says that all 'unexpected name value pairs' will be gracefully
ignored so this should not break anyones implementation. ;-). All such
parameters can safely be ignored as they are not part of the spec.

The basis of this usage is for trialling a new feature with the
intention, that if proven it may become part of a later xAP release. So we
could agree for example that Test01 contained a packet sequence number.
What
I should also mention is that for example Test06 as used in my applications
(UKUSA) is NOT to be confused with Test06 as used by say Stuart (KCSOFT).
To
that end you should regard my usage of Test06 as really
"UKUSA.Test06"
different to KCSOFT.Test06. Now whether you personally chose to validate
this is your choice - you run the risk that someone else's app may use the
same name/value pairs for a different purpose if you don't. On this list I
propose that we try and coordinate intended uses of these Test00-Test09
names such that we have a communality of interpretation on some - if you
want to play then start from Test09 downwards. If you have a proposal for a
TestXX header that you think would be useful to everyone then I will act as
a co-ordinator of the lower numbers Test00-Test04 such that we universally
agree on the information contained in these headers - I am going to propose
that we start to use a couple of these within the sequencing / confirmed
delivery / continuation context.

Lastly - I must stress again that the intended use of TestXX is for
experimenting with a feature intended to become part of a later xAP spec if
proven in usage. However there may just be a killer application where you
MUST have something in the header but it is not appropriate to propose this
for adoption in the spec - in exceptional situations this would be
acceptable to. Using a TestXX name/value header pair is valid only in the
context that the information relates to addressing, housekeeping or high
level policy implementation applicable to the whole datagram, for example
sequencing, groups, acknowledge mechanisms and priorities etc. Data content
should almost invariably be contained within the body of message.
Successful
TestXX name/value pairs will be renamed once adopted.

Kevin