End to End Quality of Service
Control in H.323 Networks
Mike Buckley
Lucent Technologies
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Inter-relationship of QoS Factors
Network
Packet Loss
Overall
Packet
Loss
Codec
Performance
Network Jitter
Network Delay
Network Factors
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Perceived
Quality
Jitter
Buffers
Overall
Delay
Application Factors
QoS Service Level
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
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Administrative Domains
Service
Domain
Service
Domain
End User
Domain
Service
Domain
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Transport
Network
Service
Domain
End User
Domain
Service
Domain
Domains - Managed Networks
Service
Domain
Service
Domain
Transport
Domain
End User
Domain
End User
Domain
Transport
Domain
Transport
Domain
Service
Domain
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Service
Domain
Service
Domain
Conventional Approach to
Delivering QoS End-to-end
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
The End-to-end (Internet) QoS Model
H.225.0, H.245
Service
Domain 1
H.225.0, H.245
H.225.0, H.245
Application Plane
Transport Plane
RSVP, DiffServ
UDP/IP
RSVP, DiffServ
UDP/IP
Transport
Domain 1
RSVP, DiffServ
UDP/IP
H.323 Signalling
QoS Signalling
Packet Flow
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
RSVP, DiffServ
Transport
Domain 2
UDP/IP
Transport
Domain 3
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.
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
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
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
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
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Application Controlled
Approach to Delivering QoS
End-to-end
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
An Application Controlled
Approach to QoS
Service
Domain 1
Application Plane
Transport Plane
Transport
Domain 1
Transport
Domain 3
Transport
Domain 2
Packet Flow
QoS Signalling
Call Signalling
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
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 control
within a Transport Domain is the responsibility of the Operator of
that domain
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
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
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Mixed Transport QoS Mechanisms
Service
Domain 1
Service
Domain 2
Application Plane
Transport Plane
Transport
Domain 4
(RSVP)
Transport
Domain 1
(RSVP)
Transport
Domain 2
(Diff Serv)
Media Flow
QoS Signalling
Call Signalling
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Transport
Domain 3
(MPLS/ATM)
The Concept of QoS Budgets
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Mapping QoS to H.323 Signals
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Protocols Involved
End User
Domain
QoSPE
Service
Domain
Terminal
H.323
H.qos
QoSPE
Service
Domain
GK
GK
H.323
H.qos
Application Plane
H.qos
Transport Plane
End User
Transport
Domain
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
Transport
Domain
Transport
Domain
QoS Signalling
Packet Flow
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
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
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
IP Networking & MEDIACOM 2004 Workshop
24 - 27 April 2001 Geneva
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