Subject: Common Parameter usage

From: Joyce Archibald <[email-masked]>
Date: Wed, 07 Mar 2001 08:08:54 +0000

Hi Greg,

I would certainly like the Tag values to be unique across all the
adaption layers, since this makes it possible to implement a common
library of routines for protocol analysis. However I realise this is
probably not possible this close to "last call".

It would help if all the UA protocol specs could structure the Protocol
Elements section like the SUA spec. i.e.
    3. Protocol Elements
    3.1 Common Message Header
    3.x Message definitions
    3.y Common Parameters
    3.z Protocol-specific Parameters

This makes the spec much easier to use as a reference document and is
also easier to maintain.

At the start of section 3.8 SUA has a table of "Common Parameter" Tag
values, it would be good if these were in fact used by all Adaption
layers. 

SUA uses Tag values beginning at 0x0100 for its protocol specific
parameters, again it would be good if other UA protocols could use their
own ranges. Perhaps, M2UA could use Tag values beginning at 0x0200 and
M3UA Tag values beginning at 0x0300 and so on.

Cheers,

Joyce

Greg Sidebottom wrote:

Hi Joyce,

Yes you are absolutely right, the two Protocol Data parameters must have
separate tags - M3UA.06 does use Tags "2" and "3" but somehow I missed
showing that in the Figure.  I can fix that in Issue 7 or use your text
proposal instead - whatever the group would like to see is fine by me. 
The
M3UA already has assignments for Tags "0xe" and "0xf" but Ken and I (and
other editors) can look at the Tags across all the adaptation layers to
see
what can be lined up.

As for the Network Appearance, it was there first before the Interface
Identifier so it is the rightful No. 1!!

Seriously .. is it your view that the Tag values should be unique across
all
the adaptation layers, or is it OK to re-use Tag value assignments
within an
adaptation layer as long as they are unique within each specific
adaptation
layer.  (For example the Network Appearance in M3UA/IUA does not apply
to
the IUA/M2UA so the Tag assignment "1" is used in IUA/M2UA for Interface
Id).  The latter is the approach taken so far but we can change this if
the
group desires.  I imagine there is no danger of running out of Tag
values!

Cheers,

    Greg

 -----Original Message-----
From:   Joyce Archibald [mailto:[email-masked]] 
Sent:   Tuesday, March 06, 2001 3:52 AM
To:     Sidebottom, Greg [BCNR:7M01:EXCH]
Cc:     [email-masked]
Subject:        Re: M2UA: Parameter usage

Hi Greg,

The format you have proposed for M3UA will not work because both types
of Protocol Data parameter use Tag 3. It is essential that different
Tags are used so that we can distinguish the different formats. 

May I suggest that you use 
  Tag = 0xe for Protocol Data 1 and 
  Tag = 0xf for Protocol Data 2
thus using common tags for parameters across the UA protocols.

Would it also be possible to change the Network Appearance Tag to a
different value, since Tag 0x1 is used by M2UA and IUA for Interface Id.

Cheers,

Joyce