H.225 Annex G and UsageIndication

Michael Fortinsky Michael_Fortinsky at VOCALTEC.COM
Sun Jan 9 03:04:46 EST 2000


Here are a few problems I've found in H.225 Annex G. They are problems of
an "editorial" nature, but should probably
be fixed in the near term (Geneva?).


(1) Section 1.7.1   -   The end of the first paragraph states the
following:

     " (Note that since " * " is a meaningful character, the template
actually includes a Boolean flag to indicate whether the address is
      specific or not. These examples use " * " to indicate a wild card,
but the actual representation in the template is through the Boolean flag.)
"

In the latest version of the Annex, there is no longer a boolean flag in
the template.
Each pattern in a template explicitly indicates whether it is a specific or
wildcard pattern.
I suggest to change the wording to:

     " (Note that templates do not use the " * " character to indicate
whether an address is specific or not because the " * " character can have
other
       meanings - e.g., within an AliasAddress. Instead, the template
explicitly specifies whether an address is a specific or a wildcard
address.
       For illustrative purposes, the examples that follow use " * " to
indicate a wildcard address.) "


(2) Section 1.7.1.2   -   The first paragraph states:

      "A border element may request the statically configured templates
from another border element."

I think there is no reason to differentiate between templates that were
configured statically and those received dynamically. I suggest the
wording:

      "A border element may request templates from another border element."


(3) Section 1.8.2.1

The third field, gatekeeperID, should be called elementIdentifier, for the
following reasons:
   - a gatekeeper does not own a descriptor - a border element does
   - to be consistent with other messages (which use the elementIdentifier
to represent the id of the relevant border element)

The Field and Description for this field should be changed to:

Field                                        Description
=================================
elementIdentifier                This is a text identifier that indicates
the owner of the descriptor (i.e., the border element that created
                                                 this message


The ASN.1 for Descriptor should also be changed from:

Descriptor ::= SEQUENCE
{
     descriptorInfo    DescriptorInfo,
     templates         SEQUENCE OF AddressTemplate,
     gatekeeperID      GatekeeperIdentifier OPTIONAL,
     ...
}

to:

Descriptor ::= SEQUENCE
{
     descriptorInfo    DescriptorInfo,
     templates         SEQUENCE OF AddressTemplate,
     elementIdentifier ElementIdentifier OPTIONAL,
     ...
}


(4) Section 1.8.2.3.3   -   There is a typo in the Description of the
transportQoS field. It currently states:

      transportQoS      Indicates where the responsibility lies for
resource reservation for the all made through this contact.

I suggest:

      transportQoS      Indicates where the responsibility lies for
resource reservation for a call made through this contact.


(5) Section 1.8.2.5   -   There is a typo - the term SecurityCapability is
misspelled.


(6) Section 2 (ASN.1 definitions)   -    the specification of serviceID is
not correct. It reads:

      serviceID      ::= GloballyUniqueID

 The "s" in serviceID should be capitalized. The correct line is:

      ServiceID      ::= GloballyUniqueID

This is actually a more serious problem, because it will cause ASN.1
compilation problems.



Michael Fortinsky
-----------------------------------------------------------------
Program Manager, Servers Group R&D, VocalTec Communications Ltd.
Email: mike at vocaltec.com      Tel: 972 9 9707768      Fax: 972 9 9561867



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