Subject: Re: ADSPEC format

From: [email-masked]
Date: Wed, 4 Sep 96 08:21:19 PDT

Roch,

Sorry, but I don't quite get why we need a length field for the
parameters.  The parameter type always uniquely defines a length,
doesn't it?  There are no actual variable-length parameters.

Bob Braden

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From: Roch Guerin <[email-masked]>
Date: Wed, 04 Sep 1996 11:48:02 -0400

Bob,

>doesn't it?  There are no actual variable-length parameters.

Absolutely, parameters are not variable length, but this was not the
source of the problems I was referring to.  Those problems had two
flavors.  The first one was that if we introduce a new parameter some
time down the road, e.g., a new general characterization parameter, all
implementations will need to be "upgraded", i.e., they cannot simply
ignore the new parameter (unless you require that it always be put at
the end) as they don't know how much to skip.  Another problem was
that because different parameters have different (fixed) lengths, the
padding is dependent on the order in which you list them.  In
particular, this complicates things when it comes to over-riding
general parameters in a service specific data fragment.

Roch