Resource and Admission Control Resource and Admission Control for - - PowerPoint PPT Presentation

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6

I nternational Telecom m unication Union

ITU-T

Resource and Admission Control Resource and Admission Control for Next Generation Networks for Next Generation Networks

Hui-Lan Lu, Ph.D.

Q.4/ 13 Rapporteur Bell Labs, Lucent Technologies

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 2

ITU-T

Outline

! Complexity of NGN QoS ! ITU-T Architecture for NGN Resource and Admission

Control

! Configuration example ! Use case ! S

ummary

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 3

ITU-T

Com plexity of NGN QoS

!

User-perceived QoS is end-to-end (cf. E.800)

!

NGN QoS is complex

• NGN applications have diverse performance needs
• IP is not designed for consist ent application performance
• Diversit y in an end-to-end path is common

—Different levels of QoS support in endpoint s —Varying types of QoS support in the t ransport —Multiple provider domains

Multi-Service Packet Transport

802.xx Access 2G/3G Wireless Cable xDSL Domain 1 IntServ Domain 4 Over-Prov Domain 2 DiffServ Domain 3 MPLS-TE

N G N

" ITU-T Q.4/ 13 is addressing associated issues in its RACF work " Closely related efforts are under way in ETS

I, 3GPPs, IETF, ATIS , etc.

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 4

ITU-T

Schem atic View of I TU-T NGN Fram ew ork Architecture

Other Networks

Service Control Functions

Transport stratum Service stratum

Management Functions

Service User Profiles Service User Profiles Transport User Profiles

Control Media Management

Application/Service Functions

3rd Party Applications

ANI

End-User Functions

Transport Control Functions

Resource & Admission Control Functions

Network Attachment Control Functions Network Attachment Control Functions

Transport Functions

NNI UNI

• Cf. Y.FRA (TD133
• Cf. Y.FRA (TD133-
• WP2/13, 01/2006)

WP2/13, 01/2006)

Resource and Admission Control Functions (RACF)

" Preserve the separation of services and transport " Bridge services and transport to enable dynamic applicat ion-driven

support for performance assurance and network border control

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 5

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I TU-T RACF Architecture

Rs Rw Service Stratum Transport Functions

Policy Decision Function Transport Resource Control Function

RACF Transport Stratum Service Control Functions (part of IMS or other) (part of IMS or other) Rt Rd Rp Rc Rn Ru

Other NGNs

Ri

Transport Enforcement Function

Interconnection Functions

Policy Enforcement Function

Network Attachment Control Functions

! Policy Decision Function

service facing, t ransport independent

! Transport Resource Control Function

service independent , t ransport dependent , net work-segment specific

! Policy Enforcement Function

t ypically part of border t ransport element s

intra intra-

• domain

domain inter inter-

• domain

domain

RACF

" Augments native transport QoS support

# Preempting transport congest ion at the

service cont rol layer

# Protecting ongoing premium traffic

" Is applicable to all network-controlled

applications (VoIP, IPTV, etc.)

• Cf. Y.
• Cf. Y.racf

racf (TD 81 (TD 81-

• WP4/ 13, 01/ 06)

WP4/ 13, 01/ 06)

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 6

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Key Roles of RACF and Related Entities

Policy Decision Function

!

Makes the overall admission decision based on policy and resource availability (including path and enforcement point selection)

!

Applies resource controls to the transport for bandwidth allocation, packet marking, gating, NAPT, etc. Transport Resource Control Function

!

Tracks transport resource usage and network topology

!

Resource-based admission control

! !

Applies L2 resource cont rols t o t he Applies L2 resource cont rols t o t he t ransport t ransport Policy Enforcement Function

!

Enforces controls applied by PDF

Overall, RACF supports

" Relat ive and absolut e QoS,

including priorit y

" Endpoints of varied QoS

control capabilities

" Push and pull models for

policy installation

" Multiple transaction models

for resource request s

" Various resource

management methods based

• n account ing, measurement

and reservat ion

" Exist ing and emerging

transport QoS mechanisms

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 7

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A Configuration Exam ple

Network Attachment Control Functions Ru Service Stratum Transport Stratum Core Network Rs Rw Rw Rc Rt Rd

PD-FE

Service Control Functions Access Network Rs Rw Rw Rc Rt

PD-FE PE-FE

Service Control Functions

PE-FE TRC-FE TRC-FE

Rp

PE-FE

Other NGNs

Customer Premises Network

PE-FE

Ri Ri

The PE-FE can reside in the

! Gateway GPRS

Support Node

! Packet Data S

erving Node

! Session Border Controller ! Cable Modem Termination S

ystem

! Access Node ! Border Gateway

RACF enables incrementally-deployable end-to-end QoS solutions through per-domain control and inter-domain communication

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 8

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Use Case: Link-Based Resource Managem ent

! LS

Ps are set up a priori for routing traffic of a specific application

! DiffServ is used for effecting desired treatment of traffic ! RACF

# Measures link utilization per service class periodically # Formulates blocking policy upon link congestion for affected paths # Makes admission decision per policy # Configures edge routers for the admitted traffic

MPLS Path

MPLS/DiffServ Network

Enterprise Network

IP Phone Softclient

Edge Router Enterprise Network

IP Phone Softclient

Edge Router Core Router

CSCF PD-FE TRC-FE CSCF CSCF- Call Session Control Function

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 9

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Sum m ary

! Bridging service control and transport, RACF enables dynamic

application-driven resource management

• Application admission decision taking into account resource availability
• Preempting transport congestion in the service control layer

! Augmenting native transport QoS support, RACF can be applied

edge-to-edge or end-to-end and be realized in various ways

! All applications involving network control can make use of RACF for

performance assurance and network border control

! The initial Recommendation on RACF (Y.racf) is targeted for

consent in July

• S

election and development of RACF protocols is ongoing

• Next steps are to address open issues such as inter-PDF communication

(intra- and inter-provider) and coordination of transactions end-to-end

• Draft Recommendations Y.123.qos and Y.enet under development

apply RACF to specific Ethernet environments

! Cooperation among related standards efforts across S

DOs is desirable in order to achieve a consistent approach

I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 1 0

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List of Acronym s

! CS

CF: Call S ession Control Function

! GPRS

: General Packet Radio S ervice

! LS

P: Label S witched Path

! NGN: Next Generation Networks ! PD-FE: Policy Decision Functional Entity ! PE-FE: Policy Enforcement Functional Entity ! RACF: Resource and Admission Control Functions ! S

DO: S tandard Development Organization

! TRC-FE: Transport Resource Control Functional Entity