Convergence of Policy based Resource Management Framework in Next Generation Networks

Transcription

1 Convergence of Policy based Resource Management Framework in Next Generation Networks Dong Sun Bell Laboraries, Alcatel-Lucent

2 Agenda Challenges Review of current works Converged model Summary 2

3 Challenges The Internet pipe provided by SPs does not seem be providing enough revenue growth and is increasingly perceived be a commodity business The very same Internet pipes also enable competirs support services as best-effort IP flows Examples: parasitic VoIP, video telephony, gaming, video streaming, web portals, etc. Demanding applications such as IPTV and VoD need finer granularity (per user/app) of resource control Uniform resource management across diversity of applications (IPTV, VoIP, VoD) and transport types (xdsl, PON, Ethernet, MPLS, IP..) Current pipe model and QoS mechanisms are inadequate support emerging multimedia applications and business model 3

4 Service and Revenue Opportunity Provide personalized service packages based on Date rate (bps), time of day, QoS, Service type (SDTV or HDTV) Capacity consumption (bytes per month) Support occasional in time services, e.g. Temporary service upgrade such as higher bandwidth for limited time such as turbo butn for web browsing/downloading Improve revenue growth QoS Differentiation of SP provided services and parasitic provider s services Usage/capacity Moniring Usage limiting for abusive applications Service aware resource management capability is crucial for SPs succeed in revenue growth and service differentiation 4

5 Unifying Resource Management Unified Application AS TFS Unified Service & Call Control CSCF MGCF MRCF Transport Adaptation, Resource Management & Policy Control??? UMTS/CDMA/WiMAx SGSN UTRAN PCRF? Policy Server GGSN PDSN/HA CDMA RAN Ethernet Router WLAN GW WiFi Access Points Cable CMTS Cable Access Modem Policy Reposiry DSL BRAS DSLAM DSL/ATM Access Modem Unified resource Unified management resource and in admission support of in Fixed support Mobile of Convergence is desirable fixed mobile convergence is desirable 5

6 ETSI TISPAN Resource and Admission Control Subsystem (RACS) AF Gq NASS I1 e4 RACS Rq SPDF A-RACF Ia Ra Re RCEF BGF CPE Access Node Transport L2T Di Point IP Edge Transport Layer Core Border Node Ds AF - Application Function NASS - Network Access Attachment L2T - Layer 2 Termination CPE - Cusmer Premise Equipment SPDF - Service Policy Decision Function A-RACF Access Resource and Admission Control Function RCEF Resource Control Enforcement Function BGF - Border Gateway Function 6

7 3GPP PCC Architecture AF Subscription Profile Reposiry (SPR) AF AF PDF Gq PDF Sp Rx Policy and Charging Rules Function Online Charging System (OCS) CAMEL SCP Service Data Flow Based Credit Control Go Go Gx PEF PEF PCEF Gy GGSN GGSN Gz GW Offline Charging System (OFCS) R5 R6 R7 7

8 3GPP2 SBBC Architecture (Rev. B) Application Function (e.g., CSCF, AS, etc.) Application Function (e.g., CSCF, AS, etc.) Tx Home Policy and Charging Rules Function Tx Policy and Charging Rules Function CRF PDF Home Network CRF PDP Ty Proxy Policy and Charging Rules Function Serving Network Ty CRF Proxy PDF Proxy TPF PEP Ty Access Gateway (AGW) TPF PEP Access Gateway (AGW) 8

9 Broadband Access DSL PacketCable 1.x PacketCable Multimedia Policy Reposiry LDAP Regional Broadband Networks BRAS Access Network CMS (Gate Controller) COPS Managed IP Network CMTS Application Manager COPS Policy Server COPS Managed IP Network CMTS Access Node (DSLAM) RG NCS Cable Access Network Cable Modem E-MTA Analog Phone Application signaling (e.g. SIP) Cable Access Network Cable Modem S-MTA Primary Line 9

10 RACF in Next Generation Networks Service Stratum Applications Application Application Support and Service Support S. User Profile Other NGN Service Components Service Control Legacy Terminals Legacy Terminals GW GW Access T. User Network Attachment Profile Control Attachment (NACF) PSTN / ISDN Emulation Service Component IP Multimedia IP Multimedia Component &PSTN/ISDN Service Component Simulation Resource and Admission Control (RACF) Other Networks Cusmer Networks NGN Terminals End-User * Access Transport Network Edge Core Core transport Transport Transport Stratum Note: Gateway (GW) may exist in either Transport Stratum or End-User. Resource and Admission Control (RACF) serves as an intermediary between NGN services and transport networks and makes them work independently 10

11 RACF s Job Services Components (e.g. IMS, Video, Web) Resource and Admission Control (RACF) 802.xx Access DSL Core Transport Core Transport Cable 2G/3G Wireless Dynamic management of a variety of resources (e.g., bandwidth or IP addresses) across varied transport networks different technologies, administrative domains, ownerships achieve end--end QoS and provide border control Service independent mechanism for transport resource management common various applications (e.g., IMS, IPTV and web based service etc.) Admission control for managing network congestion Policy-based arbitration of many--many relationship RACF provides an end--end solution in support of policy based resource management 11

12 Target IMS Architecture Application Layer Session Control Layer PSTN MGCF Mobile Network Parlay Application Web Portal Web Services Parlay Gateway (OSA( SCS) MGCF IBCF CSCF RACF p-cscf IP/MPLS Core SIP Application IMS IMS (and (and applications) applications) interacts interacts with with a variety variety of of access access and and core core transport transport networks networks via via RACF RACF for for e2e e2e resource resource management management and and QoS QoS control control 802 xx Access DSL Packet Circuit Frame, ATM Ethernet Cable FTTP/C Enterprise VPN 12

13 ITU-T RACF Architecture Service Stratum Transport Stratum NACF Ru RACF Service Control (SCF) Rn TRE-FE Rp TRC-FE Rc Rt Transport Rd Rs PD-FE Rw PE-FE Ri in other NGNs Within the NGN architecture, the RACF acts as the arbitrar for resource authorization and allocation between Service Control and Transport. PD-FE/PE-FE covers the decision and allocation of transport resources based on user/network policies such as time of day, priority, etc., TRC-FE covers admission/traffic control, within access and core transport, based on resource availability and QoS requirements PD-FE - Policy Decision Functional Entity TRC-FE - Transport Resource Control Functional Entity PE-FE - Policy Enforcement Functional Entity TRE-FE - Transport Resource Enforcement Functional Entity NACF - Network Attachment Control service-based, transport technology independent service-unaware, transport-technology dependent, network-segment specific RACF isolates specific attributes of services and transport networks 13

14 RACF Highlights RACF provides Transport Resource Management Capabilities Application-driven (network-independent) real-time control Management of transport resources within networks (access or core) and at network boundaries Policy-based authorization and allocation of the resources supporting End-user equipment of varying QoS control capabilities Push and pull models for policy control Multiple transaction models for resource authorization, reservation and commitment A combination of resource management methods based on accounting, measurement and reservation RACF interfaces Service Control Function (e.g. SIP Proxy Server or IMS) allow an Application request resources including: QoS (BW Guarantees, per flow traffic shaping/policing, priority, ) NAPT control and NAT Transversal capabilities Gate control and other border control functions RACF can interface across network boundaries support a variety of business models Addresses Session Border Control Issues Will integrate flow based charging capabilities (future) RACF covers end--end QoS control as well as border control functions 14

15 RACF Key Elements PD-FE Policy Decision Functional Entity Apply network policies resource management requests from Service Control Given an IP address pair and required BW, determine if the given flow can be supported in the network Manage resources along the flow path including NAPT Transversal and Gate Control TRC-FE Transport Resource Control Functional Entity Connection Admission Control Monir network resource utilization and network pology manage path bandwidth availability (reservation and/or monir) PE-FE Policy Enforcement Functional Entity Provides media path functions such as gate control / Firewall NAPT translation and Transversal Per flow policing and QoS-marking Can report usage status Service Control RACF consists of 2 elements: PD-FE and TRC-FE for policy control and resource control 15

16 Key Reference Point Requirements Rs: PD-FE-SCFs For SCFs request transport resource authorization and control Information exchanged: session ID, media descripr, application QoS requirements, priority, gate or NAPT control policy, authorization ken, etc. Rw: PD-FE-PE-FE For PD-FE apply controls PE-FE concerning NAPT, hosted NAT traversal, gating, bandwidth, packet marking, etc. Information exchanged: media descripr, DSCP value, bandwidth committed, bandwidth authorized, authorization ken, gate control command, NAPT control command, usage information, etc. Rt: PD-FE-TRC-FE For PD-FE request resource availability check by TRC-FE Information exchanged: media descripr, bandwidth, other network QoS requirements, network path, etc. 3 main interfaces between service control, PD-FE/TRC-FE and enforcement element 16

17 RACF Example Implementation Architecture Service Control Function (SCF) (e.g. IMS P-CSCF, VoD, IPTV etc) NACF Rn RACF TRC-FE Rc Ru Rt Rw Rs PD-FE Ri Rs PD-FE Rw Rd Rt Rp TRC-FE Rc RACF CPE TRE-FE Access Node Transport PE-FE Border Gateway PE-FE Border Gateway Transport PE-FE Border Gateway Access Network Domain Core Network Domain Each operar administrative domain should have its own PD-FE for policy control Multiple PD-FE and TRC-FE instances are allowed in the same domain PD-FE and TRC-FE can be centralized or distributed, can be a standalone device or integrated with other network devices TRC-FE may control the TRE-FE for aggregation transport QoS The deployment of RACF depends on SP s network configuration, service requirements and business model 17

18 QoS Reference Model for all Standards Bodies Service Stratum Service Control (e.g. IMS) Application Function Transport Stratum NACF/ NASS/ SPR Legends: RACF/RACS/PCC/SBBC Inter-domain Intra-domain Rs/Gq /Rx/Tx Rd/Rq/-/- PD-FE/ Ri/Rq/-/- Rt/Rq/-/- SPDF&A-RACF/ PCRF Ru/e4/Sp/- TRC-FE/ A-RACF/ -* Rc/-/-/- Rp/-/-/- Rw/Ia&Re/Gx/Ty PE-FE/ BGF&RCEF/ PCEF(GGSN/PDSN) Other NGNs ITU-T Rel 1 TISPAN Rel 1 3GPP Rel 7 3GPP2 Rev B Policy Decision Function PD-FE - Policy Decision Functional Entity SPDF - Service-Based Policy Decision Function A-RACF - Access Resources & Admission Control Function (Partial) PCRF - Policy & Charging Rules Function PCRF - Policy & Charging Rules Function (PDF & CRF) Transport Resource Control Function TRC-FE - Transport Resource Control FE A-RACF (Partial) GGSN/SGSN/RNC/Node-B (Embedded, GPRS only) PDSN/PCF/BSC (Embedded, CDMA only) Policy Enforcement Function PE-FE - Policy Enforcement FE residing in network devices (e.g. DSLAM/BRAS, GGSN/PDSN, border gateway) intra- domain BGF - Border Gateway Function (e.g. core Border node) RCEF - Resource Control Enforcement Function (e.g. IP Edge) inter-domain PCEF - Policy & Charging Enforcement Function (e.g. GGSN, TrGW) AGW (PEP Policy Enforcement Point ) (e.g. PDSN) Interface: ITU-T/TISPAN/3GPP/3GPP2 Combined view of ITU-T, TISPAN, 3GPP, 3GPP2 QoS reference models 18

19 QoS Call Flows for Wireline Networks UE UE initiates initiates service service with with media media parameters parameters in in SIP SIP INVITE INVITE P-CSCF P-CSCF verifies verifies that that UE UE is is registered registered and and forwards forwards INVITE INVITE Home Home S-CSCF S-CSCF Home Home S-CSCF S-CSCF verifies verifies that that the the requested requested service service has has a a valid valid subscription subscription session session is is routed routed called called network network elements elements Assuming Assuming all all is is well well in in called called network, network, P- P- CSCF CSCF receives receives SIP SIP 183/ /200 message message P-CSCF P-CSCF checks checks see see if if resources resources are are available available with with PDP PDP (in (in RACF) RACF) - - PD-FE PD-FE pushes pushes QoS QoS policy policy TRC-FE TRC-FE request request QoS QoS RACF RACF can can verify verify request request based based on on local local resource resource availability availability and and push push policy policy down down Service Service Edge Edge Router. Router. 2 P-CSCF S-CSCF 4 Home Network 3 Serving Network Service Edge Router BRAS, CMTS, 5 HSS RACF (PD-FE, TRC- FE, ) 6 Access Network QoS parameters come from either: SDP parameters from the UE Subscription info in the HSS 1 User Equipment IP Endpoints SIP, H.323 and MGCP Interactions among P-CSCF, RACF and network element for E2E QoS H.323 PBX 19

20 Example for UMTS 1 HSS AS P-CSCF Gx+ 7 PCRF PCRF C-TRCF A-TRCF UTRAN/ SGSN GGSN Core Network BGW Other Providers Networks 1. User initiates SIP session. Results in SIP INVITE P-CSCF 2. Based on negotiation between the user equipment and AS, P-CSCF determines how much bandwidth is required for the SIP session 3. P-CSCF issues a request PCRF for Service level QoS authorization 4. User terminal initiates a Bearer Resource Establishment request GGSN 5. GGSN requests PCRF get authorization 6. PCRF checks with A/C-TRCF(s) for resource availability. A/C-TRCF(s) will check resources with the UTRAN, SGSN and Core Network. 7. PCRF sends authorized QoS GGSN for policy enforcement 8. GGSN responds User terminal with Bearer Resource confirmation. Interactions among PCRF, A-TRCF and C-TRCF will lay the foundation for E2E QoS 20

21 Summary Service based, dynamic policy based control of network resources is viewed as crucial the profitability of telecom operars Fine granularity of QoS enables NGN/IMS support a large range of QoS sensitive applications End--end service quality assurance is essential for the fixed mobile convergence in support of anytime, anywhere ubiquius services 21