International Telecommunication Union
ITU-T
Quality of Service for Next
Generation Networks
Hui-Lan Lu, Ph.D.
Q.4/13 Rapporteur
Lucent Technologies
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
Outline
ITU-T
o Drivers and basic requirements
o NGN QoS standardization activities in ITU-T
o Resource and Admission Control Functions (RACF)
o Summary
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
2
Why?
ITU-T
NGN
802.xx
Access
Cable
Domain 1
IntServ
Domain 2 Domain 3
DiffServ MPLS-TE
Domain 4
Over-Prov
2G/3G
Wireless
xDSL
Multi-Service Packet Transport
o Dynamic support for a variety of applications (e.g., Web services, VoIP,
and IPTV) with very different performance needs
o Enabling providers to control end user experience in a heterogeneous
environment in a consistent and secure fashion
o Allowing fast introduction of performance-demanding applications
Resource
Management
Security
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
3
Key QoS Topics under Study in ITU
ITU-T
o Performance objectives, including
• Network performance classification
• Network performance allocation
o Dynamic QoS controls, including
• Negotiation of QoS requirements
• Resource and admission control
• Interworking of QoS mechanisms
• Inter-domain considerations
• Frameworks and guidelines
o Performance measurement and management
o Performance prediction
SG 12
SG 16
SG 11
SG 13
SG 4
SG 12
SG 13
SG 12
Related efforts are
A major goal is to develop a comprehensive QoS solution
underway in other
that allows incremental deployment
SDOs
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
4
NGN QoS Activities in Q.4/13
ITU-T
restoration
priority
admission
priority
resource
management
Y.enet
performance
management
Y.2111/Y.RACF
resource
management
Y.123.qos
R e c o m m e n d a tio n
Y.mpm
Y.RestPriority
Y.2171
resource request
authorization
resource
management
Y.flowreq
Y.e2eqos.1
T itle
T a r g e t fo r
C onsent
Y .2 1 7 1
A d m is s io n c o n t r o l p r io r it y le v e ls in N G N
0 7 -2 0 0 6
Y .2 1 1 1
R e s o u r c e a n d a d m is s io n c o n t r o l f u n c t io n s in N G N
0 7 -2 0 0 6
A Q o S c o n tro l a rc h ite c tu re fo r E th e rn e t-b a s e d IP a c c e s s
n e tw o rk s
0 4 -2 0 0 7
Y .e n e t
E th e rn e t Q o S c o n tro l fo r N G N
0 4 -2 0 0 7
Y .m p m
M a n a g e m e n t o f p e rfo rm a n c e m e a s u re m e n t fo r N G N
0 4 -2 0 0 7
R e q u ire m e n ts a n d fra m e w o rk fo r e n d -to -e n d Q o S in N G N
1 2 -2 0 0 7
R e s t o r a t io n p r io r it y le v e ls in N G N
0 4 -2 0 0 7
R e q u ir e m e n t s f o r t h e s u p p o r t o f s t a t e f u l f lo w - a w a r e
t r a n s p o r t t e c h n o lo g y in N G N
0 4 -2 0 0 7
Y .1 2 3 .q o s
Y .e 2 e q o s .1
Y .R e s tP rio rity
Y .flo w re q
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
5
Resource and Admission Control Functions
ITU-T
Control
Media
Management
3rd Party Applications
(See ITUITU-T Rec. Y.2012/Y.NGNY.2012/Y.NGN-FRA)
Management Functions
ANI
Application/Service Functions
Service
User
Service User
Profiles
Profiles
Service Control
Functions
Service stratum
Transport User
Profiles
Network
Attachment
Control Functions
Resource & Admission
Control Functions
Transport Control Functions
End-User
Functions
Other
Networks
Transport Functions
UNI
NNI
Transport stratum
Resource and Admission Control Functions (RACF)
™ Provide application-driven, policy-based resource management
™ Bridge service control and packet transport to dynamically guarantee QoS
and enforce certain network security measures
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
6
ITU-T RACF Architecture
ITU-T
(See ITU-T Rec. Y.2111/Y.RACF)
Service Control Functions
(IMS or non-IMS)
Service Stratum
(Diameter)
Network Attachment
Control Functions
intradomain
interdomain
Ru
Rp
PD-FE
TRC-FE
Rn
Rt (Diameter)
Rc (COPS, SNMP)
TRE-FE
Transport
Functions
Policy Decision Functional Entity (PD-FE)
o Authorizes resource requests based on policy
o Configures the transport to enforce policy
Ri
RACF
Other NGNs
Rs (Diameter)
Rd
Transport Stratum
Rw (H.248, COPS, Diameter)
PE-FE
service-facing,
transport-independent
Transport Resource Control Functional Entity (TRC-FE)
o Tracks resource usage & network topology
o Makes resource-based admission decision
service-independent,
transport-dependent,
segment-specific
Policy Enforcement Functional Entity (PE-FE)
typically part of border transport
o Enforces policy for NAPT, gating, rate limiting, packet
elements (e.g. edge router and
marking, etc.
border gateway)
ITU-T/OGF Workshop on Next Generation Networks
and Grids
Geneva, 23-24 October 2006
7
More RACF Specifics
ITU-T
Support for
o Relative and absolute QoS, including priority
o Endpoints of varied QoS control capabilities
o Push and pull modes for policy control
o Various resource management methods based on
accounting, measurement and reservation
o Existing and emerging transport QoS mechanisms
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
8
Push and Pull Modes
ITU-T
Service Control
Functions
2
1
4
6
User
Equipment
2
Token
1
RACF
T
7
T
5
3
Service Control
Functions
Policy
5
RACF
6
Policy
3
4
T
8
Transport
Functions
User
Equipment
Transport
Functions
Push Mode
Pull Mode
(Token-free operations are also possible.)
Application Signaling
RACF Control
Transport QoS Signaling
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
9
Options for Admission Control in TRC-FE
ITU-T
Depending on operator policy and network specifics:
o NULL (such as in over-engineered core networks)
o Accounting-based
• Keep track of the consumed resources from a resource pool
o Measurement-based (in-band or out-of-band)
• Audit resource use in the transport periodically via SNMP, or
• Measure directly network performance edge-to-edge(or end-to-end) via
RTCP or active/passive probes
o Part of native transport admission control
• For example, MPLS routers/switches track resource use and LSP map
o In conjunction with native transport resource reservation
• Trigger native transport resource reservation and make admission decision
based on the reservation result
o A combination of the above
• Different solutions according to services and/or network domains
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
10
A Configuration Example
ITU-T
Service Control
Functions
Service Control
Functions
Service Control
Functions
Rs
Rs
Ri
Network
Attachment
Control
Functions
Rc
PE-FE
Rw
PE-FE
Rw
TRC-FE
Rw
Rc
Rw
PE-FE
PE-FE
Rc
PE-FE
Core Network
Access Network
The PE-FE can reside in the
o Gateway GPRS Support Node
o Packet Data Serving Node
o Cable Modem Termination System
Network
Attachment
Control
Functions
Rt
TRC-FE
TRC-FE
Ru
PD-FE
Rt
Rp
Rt
Rw
Customer
Premises
Equipment/
Network
Ri
PD-FE
PD-FE
Ru
Rw
PE-FE
Access Network
Customer
Premises
Equipment/
Network
o Access Node
o Edge Node
o Border Gateway
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
11
Summary
ITU-T
o NGN QoS is an active standardization area in the ITU-T
o RACF for dynamic, application-driven resource management plays a
central role
• Y.2111/Y.RACF (on the architecture and requirements for Release 1) and
Y.2171/Y.CACPriority about to be approved
• RACF protocols are under development in SG 11
• Draft new Recommendations Y.123.qos and Y.enet address the application of
RACF to Ethernet environments
o
Other aspects are addressed by new draft Recommendations underway
(Y.mpm, Y.e2eqos.1, Y.flowreq, Y.RestPriority, etc.)
o Close cooperation among relevant SDOs is essential to the development
of consistent and interoperable standards
o Discussion of the impacts of Grids is in order
ITU-T/OGF Workshop on Next Generation Networks and Grids
Geneva, 23-24 October 2006
12