Subject: [Megaco] Liaison on H.248.resman Resource Management packages

From: Christian Groves <[email-masked]>
Date: Fri, 03 Aug 2007 11:57:17 +1000

Hello all,

As Q.3/16 Rapporteur it was agreed that I would communicate a liaison on 
a new work item H.248.resman "Resource Management" to the MEGACO mailing 
list for comment. The liaison can be found in: 
http://ftp3.itu.int/av-arch/avc-site/2005-2008/0706_Gen/WP2_liaison_statements_070706.zip 
.

Below is the text from the liaison.

Comments are welcome.

Regards, Christian (with my Q.3/16 Rapporteur hat on)

Start
----------------------

INTERNATIONAL TELECOMMUNICATION UNION

*STUDY GROUP 16*

*TELECOMMUNICATION
STANDARDIZATION SECTOR*

STUDY PERIOD 2005-2008

*TD 488 (WP 2/16)*

*English only*

*Original: English*

*Question(s):*

3/16

Geneva, 26 June - 6 July 2007

*TEMPORARY DOCUMENT*

*Source:*

Rapporteur Q3/16

*Title:*

LS to Tispan WG3, 3GPP CN and MSF on new work item H.248.resman

*LIAISON STATEMENT*

*To:*

ETSI TISPAN WG3, 3GPP CN, MSF

*Approval:*

*ITU-T SG 16 meeting (**Geneva**, 26 June – 6 July 2007)*

*For:*

Information/Action

*Deadline:*

/January 2007/

*Contact:*

Christian Groves
NTEC Australia
Australia

Tel: +61 3 9391 3457
Fax: +61 3 9391 3457
Email: [email-masked] <mailto:[email-masked]>

Q3/16 at its July meeting has started work on a new work item 
H.248.Resman “Resource Management Packages”. The scope of the work item 
is to look at ways that various resource management techniques could be 
used in partnership and between the MGC and MG to allow the MG to 
utilize resources in the most efficient manner. This work item is an 
initial draft, significant further work is expected. A background to the 
work item and approach is given below.

On analysis of the H.248 sub-series when looking at resource management 
issues the scope is largely in four areas: 1. Assigning a resource, 2. 
Resource reservation, 3. Resource reporting and 4. Resource Provisioning.

*Assigning a resource* is really the basic operation of H.248. The H.248 
connection model allows a MGC to assign characteristics to a particular 
context and its associated terminations/streams which are then 
translated to physical resources by the MG. This translation is one of 
the fundamental aspects of the H.248 connection model which allows the 
MGC to be unaware on the internal architecture of the MG.

*Resource reservation* is achieved through H.248 procedures that allow 
the MGC to reserve a resource* *at a stream level. The MGC can indicate 
that a particularly stream may have different characteristics through 
the reserve value and reserve group mechanism.

*Resource reporting* usage is largely described by ServiceChange aspects 
of H.248.1 and the congestion mechanisms described in H.248.10, H.248.11 
and H.248.32. These mechanisms describe a state change in resources, 
e.g. in / out service, a certain congestion level. AuditCapabilities and 
AuditValue command can be used to find out the current or potential 
values of the resources.

*Resource Provisioning* may be achieved through the use of base packages 
which can describe at a gateway level the system limit of the MG. e.g. 
max number of terminations in a context.

So it can be seen that there is a relatively comprehensive set of 
resource management tools already contained in H.248.

However there exists opportunities for enhancements to the H.248 
sub-series to introduce mechanisms which enhance resource management on 
media gateways. Below is such a discussion where enhancement to Resource 
management techniques may be desirable:

/ One of the problems faced by MG implementations is that they cannot 
tell what will happen in the future to a particular context/termination. 
This is a side effect of the H.248 connection model which removes 
call/session/service information //from the MG. The MG is unaware of the 
call/session/service information// and //therefore cannot predict with 
any certainty what type of resources would be needed by these 
call/session/services in the future.///

/In order to know this the MGC would have to signal this information to 
the MG. It would not be appropriate to send down a service identifier 
because the MG would then have to map these to physical resources and it 
would not necessarily have this knowledge. The MGC would have to 
indicate which elements from the H.248 connection model would be 
impacted.///

/A further complication is that the MGC will become aware of the 
call/session/service resource requirements at different times in the 
call. Thus when the MGC adds a termination on the MG it may not be fully 
aware of the service that is required and thus cannot fully indicate 
which resources are used. The MGC may also change the resources needed 
at any during the call. For example theoretically it is possible for a 
MGC to change a stream from audio to video during the call.///

The draft H.248.Resman provides several instances of enhanced resource 
management techniques in addition to addressing the above discussion. In 
order to address the complex problem of resource management Q3/16 is 
developing a generic framework (see attached draft H.248.Resman) where 
several approaches are available to allow enhanced resource management. 
These approaches are described below:

*Solution 1 - Rules Approach*

Solution 1 calls for a “rules” based approach where the MG expects the 
MGC to behave in a particular manner. For example: For optimal resource 
allocation the MG may expect that once a stream is assigned to a 
particular media (e.g. audio) that it will not change it to another 
media (e.g. Video). This could be agreed between the MGC and MG through 
the use of a package.

*Solution 2 - Configuration Approach*

Solution 2 calls for an approach whereby the MGC indicates the expected 
characteristics of the context in terms of the actual resources 
required. This could be a number of a particular type of termination. 
For example: The MGC could indicate that for a particular context it may 
have up to 5 receive only terminations.

*Solution 3 - Abstracted Approach*

Solution 3 calls for an approach whereby the MGC indicates a specific 
resource management requirement via a single code point which then 
relates directly to a particular H.248 configuration. For example: The 
MGC could indicate “conference listener” and this would then map 
directly to a send only termination configuration and a particular type 
of audio codec.

Q3/16 requests feedback from your organisation if you have extra 
requirements for enhanced resource management. If so Q3/16 would look at 
adding these requirements to their work item.

*Attachments: *

TD 515/WP 
(http://ftp3.itu.int/av-arch/avc-site/2005-2008/0706_Gen/H248_resman_output.zip)

----------------------
End.

_______________________________________________
Megaco mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/megaco