ip networking & mediacom 2004 workshop 24 - 27 april 2001 geneva end to end quality of service...

IP Networking & MEDIACOM 2004 Workshop24 - 27 April 2001 Geneva

End to End Quality of Service End to End Quality of Service Control in H.323 Networks Control in H.323 Networks

Mike BuckleyLucent Technologies


Inter-relationship of QoS Factors

Codec Performance

Network Factors

Network Delay

Network Packet Loss

Network Jitter

Overall Delay

Application Factors

Overall Packet

Loss

Jitter Buffers

Perceived Quality

QoS Service Level


Network Packet Loss, Mean Delay, Delay Variation

SERVICE

APPLICATION

TRANSPORT

QoS Service Class

Codec, Frames per Packet, Frame Size, Jitter Buffer Size, Overall Delay, Overall Packet Loss, FEC (Redundancy)

QoS Parameters


End UserDomain

Administrative Domains

ServiceDomain

ServiceDomain

ServiceDomainService

Domain

End UserDomain

ServiceDomain

Transport Network


End UserDomain

Domains - Managed Networks

ServiceDomain

ServiceDomain

ServiceDomainService

Domain

End UserDomain

ServiceDomain

TransportDomain

TransportDomain

TransportDomain


Conventional Approach to Delivering QoS End-to-end


H.323 Signalling

QoS Signalling

Packet Flow

Application Plane

Transport Plane

The End-to-end (Internet) QoS Model

Service Domain 1

Transport Domain 1

Transport Domain 2

Transport Domain 3

H.225.0, H.245

H.225.0, H.245H.225.0, H.245

UDP/IP UDP/IP

UDP/IPUDP/IP

RSVP, DiffServ

RSVP, DiffServ RSVP, DiffServ

RSVP, DiffServ


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.


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


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.

H.323 signalling to support the above


Application Controlled Approach to Delivering QoS

End-to-end


Call Signalling

Packet FlowQoS Signalling

Application Plane

Transport Plane

An Application Controlled Approach to QoS

Service Domain 1

Transport Domain 1

Transport Domain 2

Transport Domain 3


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


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


Call Signalling

Media FlowQoS Signalling

Application Plane

Transport Plane

Mixed Transport QoS Mechanisms

Service Domain 1

Service Domain 2

Transport Domain 1

(RSVP)

Transport Domain 2(Diff Serv)

Transport Domain 3

(MPLS/ATM)

Transport Domain 4

(RSVP)


The Concept of QoS Budgets

TransportDomain 1

TransportDomain 2

TransportDomain 3

EndPoint1

EndPoint 2

Transport Domain budgets

End-to-End Budgets

SignallingPath

End-Point Budgets End-Point Budgets


Mapping QoS to H.323 Signals


Protocols Involved

Application Plane

Transport Plane

Packet FlowQoS Signalling

Transport Domain

GK

QoSPEServiceDomain

Terminal

End UserDomain

End User Transport Domain

Transport Domain

GK

QoSPEServiceDomain

H.323 H.323

H.qos H.qosH.qos


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.

New Annex N of H.323


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


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.

ip networking & mediacom 2004 workshop 24 - 27 april 2001 geneva end to end quality of service...

Documents

qos service domain

domain control

qos slide

ip networking mediacom

qos endtoend slide

qos architecture

qos messages

end quality of service