Resources and Admission
Control for NGN
Tina TSOU (tena@huawei.com)
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
1
Outline
• ITUITU-T view of Next Generation Networks (NGN)
• Resource and Admission Control Functions
(RACF)
– Role
– Architecture
– Key functional requirements
• Use cases
– Bandwidth and admission control manager
– Packet interconnect
• Summary
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
2
1
Schematic View of ITU-T NGN Architecture
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
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An NGN Configuration
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
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IMS and Its Environment
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
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RACF’s Job－QoS and beyond
• Dynamic management of a variety of resources (e.g.,
•
bandwidth or IP addresses) across varied transport
networks—
networks—different technologies, administrative
domains, ownerships—
ownerships—to achieve endend-toto-end QoS
and border control (e.g., NAPT and packet filtering)
ServiceService-independent mechanism for transport
resource management common to multiple
applications (e.g., IMS and multimedia streaming)
– Admission control for managing network congestion
– Policyof manyPolicy-based arbitration
many-toto-many relationship
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
6
3
RACF－Key High-Level Requirements
• ApplicationApplication-driven (network(network-independent) realreal-time control
• Management of transport resources within networks (access
•
or core) and at network boundaries
PolicyPolicy-based authorization and allocation of resources
supporting
–
–
–
–
–
Relative and absolute QoS
EndEnd-user equipment of varying QoS control capabilities
QoSQoS-unaware, applicationapplication-QoSQoS-aware, networknetwork-QoSaware
Push and pull models for policy control
Multiple transaction models for resource authorization, reservation
reservation
and commitment
– A combination of resource management methods based on
accounting, measurement and reservation
• Dynamic control of NAPTs,
NAPTs, firewalls and NAT traversal
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
7
A Schematic View of ITU-T RACF
Service Control Functions
Service Stratum
Transport Stratum
RACF
Rd
Rs
Ru
PD-FE
Rt
Rp
Ri
TRC-FE
Rn
TRE-FE
Rw
Rc
Other NGNs
Network
Attachment
Control
Functions
PE-FE
Transport Functions
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
8
4
QoS Request Scenario－
Scenario－UE QoSQoS-Unaware, Policy Push
• 1.UE requests a service with no explicit QoS requirements
• 2.SCF requests resource authorization and allocation from
•
RACF based on the user subscription profile
3.RACF authorizes resources based on policy rules and
resource availability, and applies controls to the transport
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
9
Proxied QoS Request Procedure
(Further detail of Step 2 and 3 on the previous slide)
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
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5
QoS Request Scenario－
Scenario－UE NetworkNetwork-QoSQoS-Aware, Policy Pull
• 1.UE requests a service with QoS requirements
• 2.SCF requests resource authorization from RACF based on the requirements
• 3.RACF authorizes resources based on policy rules and resource availability, and
creates an authorization token, which is passed to UE via application signalling
• 4.UE reserves resources from the transport (with the token)
• 5.The transport checks with RACF for authorization based on the token
• 6.RACF authorizes resources
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
11
UE-Requested Resource Reservation Procedure
(Further detail of Step 4, 5 and 6 on the previous slide)
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
12
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ITU-T RACF Architecture
Service Control Functions
Service Stratum
Transport Stratum
RACF
Rd
Rs
Ru
PD-FE
Rt
Rp
Ri
TRC-FE
Rn
TRE-FE
Rw
Rc
Other NGNs
Network
Attachment
Control
Functions
PE-FE
Transport Functions
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
13
Summary of Resource & Admission Control Functions
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
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General Interface Requirements (Rs,
Rp, Rw, Rt)
•
•
•
•
•
•
RequestRequest-response transaction
Notification of asynchronous events
Reliable delivery of messages
Mutual authentication of correspondents
Integrity of information exchanged
Exchange of a combination of information
elements such assess ID, media descriptor,
priority, DSCP value, bandwidth committed,
bandwidth authorized, authorization token,gate
control command, NAPT control command,
usage information
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
15
Use Case 1: Bandwidth and Admission Control
Manager
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
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Use Case 2: Packet Interconnect
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
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Summary
• Bridging service control and transport, RACF provides
•
•
•
for applicationapplication-driven realreal-time resource management
With RACF, the admission decision for a service
request can take into account resource availability as
dictated by endend-toto-end performance requirements
Any services involving networknetwork-based service control
can make use of RACF to provide for QoS and border
control
ITUITU-T is addressing the remaining issues for RACF,
including
– InterInter-RACF communication (inter(inter-PDF and interinterTRCF)
– Coordination of transactions end-to-end
Workshop on NGN
Interconnection (2(2-3 May 2007),
Bahrain
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