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
Outline ITU-T ! 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 2
Com plexity of NGN QoS ITU-T N G N 802.xx Cable Access Domain 2 Domain 1 Domain 3 Domain 4 DiffServ IntServ MPLS-TE Over-Prov 2G/3G xDSL Wireless Multi-Service Packet Transport ! 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 " 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 3
Schem atic View of I TU-T NGN Fram ew ork Architecture ITU-T 3 rd Party Applications Control Media Cf. Y.FRA (TD133- Cf. Y.FRA (TD133 -WP2/13, 01/2006) WP2/13, 01/2006) ANI Management Application/Service Functions Management Functions Service User Service User Profiles Profiles Service Control Functions Service stratum Transport User Network Network Resource & Admission Profiles Attachment Attachment Control Functions Control Functions Control Functions Transport Control Functions End-User Other Functions Networks Transport Functions UNI NNI Transport stratum 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 4
I TU-T RACF Architecture ITU-T Service Control Functions Cf. Y.racf racf (TD 81 (TD 81- -WP4/ 13, 01/ 06) WP4/ 13, 01/ 06) Cf. Y. (part of IMS or other) (part of IMS or other) Service Stratum Rs Transport Stratum Other NGNs Rp Rd Policy Transport Decision Network Attachment Ru Resource Ri Rt Function Control Functions Control Function RACF intra- - intra Rc domain domain Rn Rw inter- - inter Transport Policy domain domain Interconnection Enforcement Enforcement Functions Function Function Transport Functions ! Policy Decision Function RACF service facing, t ransport independent " Augments native transport QoS support ! Transport Resource Control Function # Preempting transport congest ion at the service independent , t ransport dependent , service cont rol layer net work-segment specific # Protecting ongoing premium traffic ! Policy Enforcement Function " Is applicable to all network-controlled t ypically part of border t ransport element s applications (VoIP, IPTV, etc.) I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 5
Key Roles of RACF and Related Entities ITU-T Overall, RACF supports Policy Decision Function ! Makes the overall admission decision " Relat ive and absolut e QoS, based on policy and resource availability including priorit y (including path and enforcement point " Endpoints of varied QoS selection) control capabilities ! Applies resource controls to the " Push and pull models for transport for bandwidth allocation, packet marking, gating, NAPT, etc. policy installation " Multiple transaction models Transport Resource Control Function for resource request s ! Tracks transport resource usage and network topology " Various resource ! Resource-based admission control management methods based ! ! Applies L2 resource cont rols t o t he Applies L2 resource cont rols t o t he on account ing , measurement t ransport t ransport and reservat ion " Exist ing and emerging Policy Enforcement Function ! transport QoS mechanisms Enforces controls applied by PDF I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 6
A Configuration Exam ple ITU-T Service Control Service Control Functions Functions Service Stratum Rs Transport Stratum Rs Rd Other NGNs Ri Ri PD-FE PD-FE Network Rt Rp Rt Attachment Ru Control TRC-FE TRC-FE Functions Rc Rw Rw Rw Rc Rw Customer PE-FE PE-FE PE-FE PE-FE Premises Network Core Network Access Network The PE-FE can reside in the ! Gateway GPRS Support Node ! Cable Modem Termination S ystem ! Packet Data S ! Access Node erving Node ! Session Border Controller ! 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 7
Use Case: Link-Based Resource Managem ent ITU-T CSCF- Call Session Control Function CSCF CSCF PD-FE TRC-FE Edge Edge Router Router Enterprise MPLS/DiffServ Enterprise Network Network Network IP Phone Core Router IP Phone Softclient Softclient MPLS Path ! 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 I TU-T W orkshop “NGN and its Transport Netw orks“ Kobe, 2 0 -2 1 April 2 0 0 6 8
Sum m ary ITU-T ! 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 9
List of Acronym s ITU-T ! 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 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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