End to End Quality of Service Control in H'323 Networks Mike Buckley Lucent Technologies

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End to End Quality of Service Control in H.323
Networks Mike BuckleyLucent Technologies
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Inter-relationship of QoS Factors
Network Packet Loss
Network Jitter
Network Delay
Application Factors
Network Factors
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QoS Parameters
QoS Service Class
SERVICE
Codec, Frames per Packet, Frame Size, Jitter
Buffer Size, Overall Delay, Overall Packet Loss,
FEC (Redundancy)
APPLICATION
Network Packet Loss, Mean Delay, Delay Variation
TRANSPORT
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Administrative Domains
Transport Network
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Domains - Managed Networks
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• Conventional Approach to Delivering QoS
  End-to-end

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The End-to-end (Internet) QoS Model
Application Plane
Transport Plane
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H.323 End-to-end QoS Support

• H.323 Appendix 1 Allows for
• End Points to indicate ability to support RSVP
  prior to call set-up,
• synchronization of QoS capability signalling with
  RSVP signalling between end points at call set-up.

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Problems with this Approach

• BUT
• Transport domains may support different QoS
  mechanisms and policies.
• Who owns the end to end picture?
• No mechanism to select transport domain on basis
  of QoS levels supported. c.f choice of
  alternative long distance carriers.
• QoS messages are not signalled to the service
  provider - how can he control the QoS levels
  offered?
• Need a business model for supplying and charging
  for QoS

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Current Work - Imperatives

• NEED
• A new approach.
• An end to end QoS architecture.
• Domain by domain control.
• A model that allows and supports charging for
  QoS.

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• Application Controlled Approach to Delivering QoS
  End-to-end

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An Application Controlled Approach to QoS
Application Plane
Transport Plane
Packet Flow
QoS Signalling
Call Signalling
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Advantages of the Application Controlled Approach
to End-to-end QoS

• CLEAR BUSINESS MODEL
• The Application Service Provider is in the
  driving seat. End-to-end (inter-domain) QoS
  control takes place within the Application Plane.
  (Between Service Providers)
• Required end-to-end QoS levels are established
  within the Application Plane (Between the End
  User and Service Provider)
• Transport Domains (Operators) provide a QoS
  service to the associated Service Domains
  (Service Providers). QoS controlwithin a
  Transport Domain is the responsibility of the
  Operator of that domain

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Advantages of the Application Controlled Appoach
to End-to-end QoS (Cont)

• OTHER ADVANTAGES
• A common interface can be defined between a
  Transport Domain and its associated Service
  Domain even though different QoS mechanisms may
  be present within the Transport Plane
• No QoS information need be exchanged between the
  End User and Network Operator or between Network
  Operators
• Application Controlled Firewalls and NATS can be
  accommodated

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Mixed Transport QoS Mechanisms
Application Plane
Transport Plane
Transport Domain 4 (RSVP)
Transport Domain 1 (RSVP)
Transport Domain 2 (Diff Serv)
Transport Domain 3 (MPLS/ATM)
Media Flow
QoS Signalling
Call Signalling
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The Concept of QoS Budgets
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• Mapping QoS to H.323 Signals

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Protocols Involved
QoSPE
ServiceDomain
GK
H.323
H.323
H.qos
H.qos
H.qos
Application Plane
Transport Plane
End User Transport Domain
Transport Domain
Transport Domain
QoS Signalling
Packet Flow
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Additions to H.323 Protocols

• QoS is determined on a per media stream basis so
  QoS is negotiated per media stream via H.245.
  New fields in H.245 under development.
• QoS Class may be requested by End User via H.245
  or H.225.0. Additions to both protocols under
  development to enable this.
• QoS characteristics of terminals may be
  registered with service providers. This involves
  additions to H.225.0 RAS.

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New Vertical Protocol Required (H.qos)

• Used to signal QoS parameters (max delay, max
  jitter, max packet loss) to each domain
• Typically will be between GK or Media Gateway
  Controller and Edge Router or Transport Resource
  Manager
• Candidates H.248/Megaco, COPS or possibly RSVP

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Summary

• End to end signalling of RSVP support by
  terminals is already provided for in H.323
• New domain by domain QoS approach under
  development along lines of TIPHON model
• New H.323 Annex N will include this functionality
• New protocol H.qos will be required to implement
  domain by domain control.