Subject: Study Group 16 Meeting Results

From: "Tom-PT Taylor" <[email-masked]>
Date: Mon, 11 Jun 2001 08:16:40 -0400

The following extracts come from meeting report of the Study Group 16
meeting just concluded.  The complete report may be found at
  http://standard.pictel.com/ftp/avc-site/0105_Por/WP2_Report_010608.zip

I will be updating the Megaco FTP site with copies of the relevant
documents.

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3.7.2.2	H.248

3.7.2.2.1	D130: Proposed Implementor's Guide for the H.248 Series
[Ericsson]

Remove proposed section 6.82 as consensus does not seem to exist for this
change at this time since sufficient time has not passed to collect
comments. The final IG for approval appears in TD15/PLEN.

3.7.2.2.2	TD41/WP2: Communication from the Chairman IETF Megaco
Working Group on Descriptors For Megaco/H.248 Annex C Properties [IETF
MEGACO]

The clarifications proposed in TD41 are beneficial and should be documented.
However, it is felt that a specific proposal should be presented to the
Megaco mail list to allow time for implementers to comment on the changes.
This should be targeted for either V2 or the next implementer's guide. Any
proposal to deprecate code points should be accompanied with a package that
would allow setting these properties in the MG, unless the property in Annex
C is truly unused.

No new Annex C codepoints will be added until this issue is resolved.

........

3.7.3.3	H.248 V2

3.7.3.3.1	D93: Handling of multiple pending transactions in H.248
[Ericsson]

There were no objections to this proposal - it was accepted for H.248 V2.
The new error code will not appear in Annex L which is up for consent at
this meeting - it will appear later (possibly in an implementer's guide).

3.7.3.3.2	D129: Extendable Context Properties for H.248 v2 [Ericsson]

There were no objections to this proposal - it was accepted to H.248 V2.
There is a possibility that the context property could benefit from the
"reserve group" or "reserve value" semantics.

3.7.3.3.3	TD31/WP2: Recommendation H.248(V2) [editor]

There are no changes to V2 since the Launceston meeting. The current plan is
to present V2 for consent at the next SG16 meeting (around February 2002).
Delegates are encouraged to review V2 in detail.

3.7.3.3.4	TD84/WP2: Recommendation H.248 V2 [editor]

TD84 is the latest draft of H.248 V2 including the additions approved at
this meeting. TD84 was not reviewed since the material added was approved.
Delegates are strongly encouraged to review TD84 before the next meeting and
to prepare comments.

3.7.3.4	H.248 Annex L

3.7.3.4.1	D128: H.248 Annex L - Error Codes and Service Change Reason
Description [Ericsson]

There was some discussion about the need for Annex L to cover cases such as
where a piece of equipment (for example, an analog line or a BRI station) is
not connected or is not powered. The feeling is that this case could be
interpreted appropriately by the MGC and the appropriate cause value sent
along. Also, specific faults can be covered in error codes defined in
packages that describe the special behavior.

There were no objections to moving Annex L forward for AAP. The final text
appears in TD14/PLEN.

3.7.3.5	H.248 Annex M.1

There were no contributions for Annex M.1. Annex M.1 is currently in an
unfinished state.

3.7.3.6	H.248 Annex M.2

3.7.3.6.1	D131: H.248 Annex M.2, Congestion Handling Package
[Ericsson]

There was comment that the name might be confusing (there may be other
packages related to congestion control). The name will be changed to "Media
Gateway Resource Congestion Handling" package to attempt to avoid confusion.

There were no other objections - Annex M.2 will be moved for approval at
this meeting. The final text appears in TD16/PLEN.

3.7.3.7	H.248 Annex M.3

3.7.3.7.1	TD38/WP2: H.248 Packages For Transmission Of Data Over
Analog Lines [editor]

TD38 indicates that the proposed package M.3 has been withdrawn as it was
merged with an IETF proposal. The IETF draft appears in TD38. The IETF
proposal has not yet gone for working group last call.

3.7.3.8	H.248 Annex M.4

3.7.3.8.1	D108: Multimedia Support Using the Decomposed H.323/H.3XX
Gateway Architecture [Lucent]

D108 was presented to provide information and justification for the approach
taken in Annex M.4. There were no comments on this material.

3.7.3.8.2	D127: Proposal for the new Annex M.4/H.248 [NTT DoCoMo]

Comments from delegates included:
·	Section 4.4 - what are units for MUXPDU sent? (count?)
·	Section 4.1.5 - "octet strings" should be "octet string"
·	Section 5.2 - should this be an event? Seems OK as a property -
consider rewording explanation
·	Section 5.1.2 - check heading numbering - also, need to define
"possible values"
·	Section 5.5 - text needed to define procedures
·	Section 6 - need to defined possible values, procedures
·	Binary tags needed for several items (e.g., package Ids)
There is no objection to add this material into M.4, provided the editorial
comments above are addressed.

3.7.3.8.3	TD39/WP2: Draft Annex M.4 to H.248 [editor]

Comments from delegates included:
·	Need units for "count"
·	Need binary tags
·	M.4.4.2.1 - need to add text describing how to select subsets - is
length needed in observed events descriptor parameters
·	M.4.5.2 - need to explain better the circumstances under which and
MG makes the decision to open a separate H.245 channel
·	Mr. Taylor believes we need to resolve the principle of how to
determine whether a given property applies to local/remote vs. local control
(and possibly termination state).

TD72r1/WP2 is the updated M.4 containing changes to address these comments
and the incorporation of D127. Editor C. Sayre has requested package
identifier values from IANA, but has not yet heard a reply.

There were no comments or objections to moving M.4 forward for consent and
approval via AAP. The final test appears in TD41/PLEN.

3.7.4	New Supplement to H.248 to Capture Package Work

3.7.4.1	TD76/WP2: H SERIES Supplement 2 : H.248 Packages Guide Release 1
[editor]

This supplement was reviewed with no comment on its content. Therefore, this
supplement is considered ready to publish. The final text appears in
TD26/PLEN.

......

3.7.5.2	New Packages for H.248

3.7.5.2.1	D109: Basic H.248 Packages for Support of External Signal
Sources [Avaya]

Comments from delegates:
·	Does not seem to fit H.248's intent
·	Need more information on scenarios, architecture
D109 was not accepted as the basis for a standard package at this time. A
better explanation is needed to justify this proposal.

3.7.5.2.2	D156: Requirements for H.248 Load Control Package -
Aggregate Bearer [Israel]

Comments from delegates included:
·	Do these requirements primarily define the operation of the ABAC?
These are background for basic requirements of the package.
·	Can media types be mixed within aggregate bearer? If so, what is a
proposal for QoS parameters? Could define aggregate with most stringent QoS
parameters, then allow multiple media types within that aggregate bearer.
But, it would be simpler to put each media type in its own aggregate bearer.
Requirements do not disallow the use of separate aggregate bearer for each
media type. Don't understand how to request different QoS parameters for
media streams within an aggregate bearer.
·	A similar proposal was accepted in principal at last Tiphon meeting,
but not enough time to close on bandwidth reports.
·	It would be nice to see the requirements captured in the actual
package text.
·	Should consider review of architectural implications in Q.B, and
also in Q.F.

The requirements detailed in D156 should appear in the package text to
provide a better understanding of the package.

3.7.5.2.3	D157: Improved H.248 Load Control for Aggregate Bearer
[Israel]

There were no objections to the items proposed in D157. Proponents of the
aggregate bearer control are expected to produce the packages for review at
future meetings.