Re: [dispatch] Charter proposal for Q4S WG ( formerly Q-HTTP) Version 1

Hi Harald,

The approach does no assume the details of the particular implementation. The protocol sends ALERT when any constraint is being violated, and these ALERTs can be monitored using DPI and change DSCP on the fly. However, the protocol does not assume it. The protocol only allow participants to know the quality measurements and to be aware of the alerts. After an alert is received , a lot of implementations are possible . Following are some examples:

   - use DPI and change DSCP packet marking  ( network aware of this protocol) and/or other type of QoS actions over network elements like changes on traffic mode at acces nodes or Path computation element function invocation.
   - invoke a supra entity  (policy service) in charge of modify quality profiles on ISPs
   - invoke a policy server which belongs to an ISP and ask for changes on QoS profles
   - react with adaptative mechanisms ( like reduce bit-rate or functionalities of the application)
   - simultaneously apply adaptative solution and QoS profile change through DPI, policy servers or whatever.

Therefore the answer to your question is that the Q4S does not assume that. We will say it explicitly in the charter

thanks!

- jose javier

________________________________
De: Harald Alvestrand [mailto:harald@alvestrand.no]
Enviado el: lunes, 20 de diciembre de 2010 14:36
Para: GARCIA ARANDA, JOSE JAVIER (JOSE JAVIER)
CC: 'dispatch@ietf.org'; pedrochas@dit.upm.es; CUBILLO PASTOR, CLARA (CLARA); ORTIGA HERRERA, GUADALUPE (GUADALUPE); jquemada@dit.upm.es; HERRANZ PABLO, SONIA (SONIA); gabriel@dit.upm.es; barcenilla@dit.upm.es; jsr@dit.upm.es; DIAZ VIZCAINO, LUIS MIGUEL (LUIS MIGUEL)
Asunto: Re: [dispatch] Charter proposal for Q4S WG ( formerly Q-HTTP) Version 1

On 12/13/10 16:39, GARCIA ARANDA, JOSE JAVIER (JOSE JAVIER) wrote:

Hi everybody,

Here is the charter proposal for Q4S ( Quality for service) WG. This WG will include the achieved works with  "Q-HTTP"
Forgive me if this has been asked before....

does this approach (out-of-band measurements on a different set of ports/protocols than in fact used by the application) assume that the network is not doing deep packet inspection or differential treatment of services?

Is there an interaction with DSCP packet marking - could the measurement setup specify DSCP codepoints to be set on packets (and, knowing that these are changed en route, report on the DSCP codepoints of incoming packets)?

In both points, it would be nice if the charter said whether it was in or out of scope.

                      Harald

Thanks for your comments

Description of Working group
============================

   Problem Statement:

   The QoS over Internet is a hot issue today. Current QoS handling
   mechanisms used in  modern network transport layers (MPLS, RSVP,
   Diffserv,Traffic Engineering) do not provide  themselves a
   QoS-on-demand end-to-end solution and existing adaptative
   solutions based on In-band Control protocols (such as RTCP)
   are very difficult to combine with any other protocols for which
   they have not been designed for.

   Four Network Parameters comprises the QoS at application level:
   Bandwidth, packet-loss, latency and Jitter.

   Interactive-video applications define flows in both directions.
   Different applications require different constraints (in terms of
   latency, jitter, packet loss) in one or both directions and
   different responsiveness. The proposed solution must be an
   effective out-of-band application level protocol capable of
   reacting when any of these constraints are violated. Such protocol
   must trigger adaptive solutions and/or QoS network profile changes.

   Currently content providers are only able to provide services based
   on adaptative methods or last-mille deployments which prefer
   dedicated network resources (vs. Internet), and therefore, restricts
   the subscriber population and increases the costs.

   Objetives:

   The goal of this working group is to define a
   QoS application-level  standard protocol optimized for its use over
   the internet that may be widely implemented and easily managed
   by application developers and service providers.

   The core technical considerations for such protocol include, but
   are not necessarily limited to, the following:

   1. Protocol design to be used in interactive applications (including
      virtualized videogames,and interative-video applications)

   2. Ensuring interoperability with all existing transport protocols

   3. Optimizing for low bit rates (typlically below 2.4 kbps)

   4. To ensure a feasible practical implementation based on
      policy servers and interoperability between service providers

   Deliverables:

   1. Specification of protocol that meets the requirements in the
      form of an Internet-Draft that defines the negotiation of QoS
      parameters, the measurement process and alert mechanisms.

   2. Dimensioning rules and performance analysis

   3. A set of technical requirements for a practical
      implementation which may include adaptative solutions and/or
      QoS profile modification.

Goals and Milestiones
=====================

Nov 2010    Submit Internet-Draft as a proposed standard for QoS
             application-level protocol

             Proposed charter for Q4S WG

             Informational document with rules for dimensioning
             and performance analysis

             Specification of architecture document for implementation

- Jose Javier

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