Policy-based Accounting Tanja Zseby GMD FOKUS - German National Research Institute for Information Technology Competence Center Global Networking (GloNe)

January 24-26, 2000Merit Consortium Meeting2 Competence Center Global Networking (GloNe) Open Source Centre Internet Multimedia Applications Group Communication QoS Modules Flow Treatment Generic Charging IPTel2000 COST263 - Quality of future Internet Services QofIS2000 GI (KuVS), NEC, Uni. Karlsruhe, MCI Active Internet Lab: MI N T, QIPTel in DS, CADENUS,... BANG, RealCast, CADENUS,... Susie, IPMM, Quasimodo, AAA Discman, T-Nova,... Discman, CADENUS, QIPTel in DS,... BANG, Discman, CADENUS, QIPTel,... infrastructure projects events

January 24-26, 2000Merit Consortium Meeting3 GMD Charging and Accounting Projects International Projects ACTS 320 SUSIE: Charging and Accounting for Premium IP COST263: Quality of Internet Services, WG2 Charging for QoS EURESCOM P906 QUASIMODO: Quality of Service Methodologies: Measuring, Managing and Charging QoS IP Meter Modules (Hitachi, Japan) National Projects Projects with Deutsche Telekom/T-Nova-Berkom –IPTAR - IP Tariffing –ATARI - ATM Tariffing (finished) –ONTARIO - Online Tariffing Options (finished) IP GIGA MEDIA (DFN - German Research Network) Standardisation activities Contributions to ETSI NA 8 Working Group: Mechanisms and Parameters for Charging in IP-based Networks IRTF AAAARCH Research Group; IETF AAA Working Group

January 24-26, 2000Merit Consortium Meeting4 Overview Charging and Accounting for IP Services Future Service Provider Options –Tariff Variables –Charging Schemes Policy-based Accounting –Charging and Accounting Model –Tariff Formula Language –Charging Information Protocol Interaction with Authorization Multicast Accounting Conclusion

January 24-26, 2000Merit Consortium Meeting5 Charging and Accounting for IP Accounting: Collection of data about resource usage The need for charging and accounting: –Control resource usage and reservation in multi-service networks –Give incentives to use only required resources –Prevent waste of bandwidth –Provide signals for capacity planning But: What kind of accounting architecture do we need ?

January 24-26, 2000Merit Consortium Meeting6 Future Service Provider Options Variety of Provider Characteristics –Size and Purpose (e.g. small ISP, large backbone operator) –QoS provisioning technique (e.g. DiffServ, IntServ) –Service classes –Charging scheme(s) and models –Agreements with other providers (e.g. data exchange, distribute tasks) –Existing Infrastructure (MIBs, profile meters, etc.) Variety of User Profiles –Number of flows, flow granularity, traffic profiles, unicast/multicast –User preferences (e.g. online charging, itemized invoices, spending limits) Potential Distribution of accounting tasks among different entities –Provisioning of accounting service by other providers or even users Accounting has to be flexible

January 24-26, 2000Merit Consortium Meeting7 Charging Schemes (Examples) Three-Term-Charging: Access, Volume, Time C = S + a T + b V Karsten et al [KaSW98]: virtual resources derived from flowspec Delgrossi/Ferrari [DeFe98]: buffer, computing capacity, schedulability, distance Kilkki: Simple Integrated Media Access (SIMA) MacKie-Mason/Varian: Smart Market

January 24-26, 2000Merit Consortium Meeting8 Tariff Variables Access-line speed Buffer occupancy FlatrateResource-based TariffsCongestion-based Tariffs QoS Dimensions Usage Dimensions Reservation ParametersProfil Parameters VolumeTime Hop Count Tariff Components Packets involved Zone Distance Geographical Distance

January 24-26, 2000Merit Consortium Meeting9 Service and Tariff Examples

January 24-26, 2000Merit Consortium Meeting10 Policy-based Accounting Flexibility –Make accounting components configurable –Re-Use existing components (MIBs, admission control functions) –Define common configuration interfaces for different types of accounting components (e.g. different meter types) Efficiency –Control allocation of resources for accounting –Adapt accounting components to charging task (required parameters, meter accuracy) Interaction with Authorization –Use authorization data bases, messages, mappings, languages, etc. –Authorize accounting services (e.g. online charging, itemized invoice)

January 24-26, 2000Merit Consortium Meeting11 Policy-based Accounting Policies can be used for : Allocation of resources for accounting (meters, collectors,...) Adaptation and configuration of accounting elements at different layers to particular accounting tasks Common description of configuration for different types of accounting module Policy-based accounting model: Utilization of existing policy framework definitions and protocols Integration of RTFM Modules into generic AAA model Definition of interfaces to authorization data bases and modules

January 24-26, 2000Merit Consortium Meeting12 Real-Time Traffic Flow Measurement (RTFM) Meter Reader Manager Analysis Application Configuration Usage Data Control Usage Data RTFM IETF working group (inactive) RFCs NeTraMet 4.3 RTFM conformant meter Based on SNMPv2 Meter configuration via SNMP (ruleset) –which flows should be measured –which attributes should be stored Manger can control multiple meters Support for DiffServ codepoint RSVP Message Parser from CEFRIEL

January 24-26, 2000Merit Consortium Meeting13 Policies at Different Layers Accounting Layer Accounting Configuration (e.g. inter-domain agreements) Accounting Policy Charging specific requirements Charging Layer Charging Configuration (e.g. charging formula) Charging Policy User/Service specific requirements Charged data Metering Layer Meter Configuration (e.g. classifier rules, metering intervals) Metering Policy CI PI Collecting requirements DI Collecting Layer Collecting Configuration (e.g. meter location) Collecting Policy Accounting requirements Billing Layer Billing Configuration (e.g. bill template) Billing Policy PI = policy interface; CI = configuration interface; DI = data interface Accounting data Collected data Metered data Included in ETSI NA8 draft document “Parameters and Mechanisms for Charging in IP based Networks”

January 24-26, 2000Merit Consortium Meeting14 Policy-based Accounting Architecture Provider Domain A Provider Domain B

January 24-26, 2000Merit Consortium Meeting15 Premium IP Network Accounting Record Flow Description (Src/Dest IP and portnumbers) Record Type Measurement Point Identification (e.g. IP Addr.) Data Extension Used Resources (#Packets, #Bytes,...) Reserved Resources (Flowspec parameters) Included in ETSI NA8 draft document “Parameters and Mechanisms for Charging in IP based Networks” ADIF description of Elements ADIF-to-PIPNAR converter

January 24-26, 2000Merit Consortium Meeting16 # setup charge sc = 0.5 # volume unit in bytes vu = # price per volume unit pv = 0.5 # time unit in secs tu = 100 # price per time unit pt = IF(AND(td>=TIME("00:00:00"), td<TIME("05:00:00")), 0.5, IF(AND(td>=TIME("05:00:00"), td<TIME("21:00:00"), 0.8, 0.5)) # tariff formula p = sc + (v/vu)*pv + (t/tu)*pt TFL: Tariff Formula Language Allows the description of charging formulas and utility curves Mathematical operations (addition, multiplication, etc.) Mathematical functions (exponential function, square root, etc.) Logical functions (AND, OR, NOT) Conditional expressions (if/then/else) Pre-defined charging variables

January 24-26, 2000Merit Consortium Meeting17 Exchange of Tariff Information Diameter Charging Information Protocol (CIP) –Informs users about current tariffs –Server maintains service and tariff information –Clients request information (push or pull mode) Push modePull mode

January 24-26, 2000Merit Consortium Meeting18 Online Charging Plot Prices t p Collector NAR Price Calculation Tariffs (TFL) Meter

January 24-26, 2000Merit Consortium Meeting19 Tariff Comparison

January 24-26, 2000Merit Consortium Meeting20 AAA Server with Accounting as Separate Service Generic AAA server Rule based engine Application Specific Module Policy Events Accounting Module Service 5 Metering 6 Acct Data 3 2

January 24-26, 2000Merit Consortium Meeting21 AAA Server with Accounting as Part of the Service Generic AAA server Rule based engine Application specific Module Policy Events Accounting/ Metering Service 5 Acct Data 3 5

January 24-26, 2000Merit Consortium Meeting22 Example: Interaction with Authorization User AAA Server Service Equipment Visited ISP Home ISP Collectors Meters Accounting Records (ARs) Service parameters including Accounting Policy Charging Policies Bill Charging & Billing configuration 7 ARs 8 (optional online charging)

January 24-26, 2000Merit Consortium Meeting23 Multicast Accounting Costs of multicast provisioning –Bandwidth savings vs. additional overhead –Dependent on group size and membership distribution (sparse,dense) Resource usage difficult to meter –Number and distribution of receivers unknown –Bandwidth savings vary due to dynamic groups –IntServ: RSVP to determine group distribution –DiffServ: unknown resource usage might influence QoS traffic Cost allocation –sender and/or receiver payment –cost sharing between receivers

January 24-26, 2000Merit Consortium Meeting24 Cost Sharing [Herzog] R2 I R1 PATH + [C(S, I)] PATH + [C(S, I)*N1/N3 + C(I,R1)] PATH + [C(S, I)*N2/N3 + C(I,R2)] RESV + [N1] RESV + [N2] RESV + [N3=N1+N2] N1, N2: Number of receivers at node R1,R2 N3: number of upstream receivers C(X,Y): costs for transport between X,Y

January 24-26, 2000Merit Consortium Meeting25 The Chuang-Sirbu Law from [ChSi98] L mc  L uc · N 0.8 Flat rate for dense mode P mc = P uc · N 0.8 for sparse mode

January 24-26, 2000Merit Consortium Meeting26 Conclusion Flexible Accounting –Provider characteristics –Charging schemes –User profiles Policy based Accounting –Layered Model –Tariff Formula Language –Accounting as part of the Service or as separate service –Interoperation with authorization Multicast Accounting introduces further requirements Further Information:

January 24-26, 2000Merit Consortium Meeting27 Call for Papers IP Telephony Workshop (IPTel2000) –April 12-13, Berlin, Germany –Submission (Abstract): January 31, 2000 (Deadline will be extended !) Quality of future Internet Services (QofIS2000) –September 25-26, Berlin, Germany –Submission: March 29,