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

March 30, 2000IRTF Meeting - AAAARCH RG2 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. acc. indication, itemized invoices, spending limits) Potential Distribution of accounting tasks among different entities –Provisioning of accounting service by other providers or even users Accounting Architecture has to be flexible

March 30, 2000IRTF Meeting - AAAARCH RG3 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

March 30, 2000IRTF Meeting - AAAARCH RG4 Why do we need accounting policies ? Different sessions may have different accounting requirements or preferences (e.g. if charging schemes differ) Different users might prefer different accounting services for the same session type (e.g. accounting indication, itemized invoice) Different accounting infrastructure (standardized notation for configuration useful) Peer providers might require a certain accounting record type or report interval ==> dynamic configuration of accounting architecture needed Idea: Transport configuration information via accounting policies

March 30, 2000IRTF Meeting - AAAARCH RG5 Accounting Policies Accounting policies: define rules for transport and storage of accounting data –What kind of accounting records should be generated –Where to send (to which entities) –When to send and how often –Where stored –How long stored –Who is allowed to access This influences –Meter configuration (what attribute, how often measured) –Data collection process (e.g. collect info from authorization event log) –Accounting record distribution (which AAA sends what to whom) –Accounting record storage (location, expiration time, etc.)

March 30, 2000IRTF Meeting - AAAARCH RG6 Intra-Domain Accounting Provider End System Service Equipment Meter System AAA Billing Service Usage Acc-Records Acc. Policies config Accounting policies are fixed Manually configured by provider No transport of accounting policy needed Accounting is part of the service Meter records Acc. Records ASM User

March 30, 2000IRTF Meeting - AAAARCH RG7 Inter-Domain Accounting (Roaming Example) User Foreign Provider End System Service Equipment Meter System AAA Service Usage Home Provider AAA 1. AccPolReq 3. AccRec config Billing ASM 2. AccPolAck Meter records

March 30, 2000IRTF Meeting - AAAARCH RG8 config Accounting Indication Provider End System Service Equipment Meter System AAA 1. AccPolReq 2. AccPolAck ASM User 3. AccRec

March 30, 2000IRTF Meeting - AAAARCH RG9 AAA Server Authorization Authentication Accounting Meter System 6. Meter records AAA-1 1.AccPolReq AAA-2 8.AccRec 5. config 3.AccPolAck 4.Enforce AccPol 2.O.K. 7. Accounting records ASM

March 30, 2000IRTF Meeting - AAAARCH RG10 Meter Systems Meter Manager RTFM Meter (NeTraMet) Collector Meter SNMP (conf) Meter SNMP (data) AAA Meter Records Cisco NetFlow Meter System UDP (data) AAA Meter Records Flow Collector Filter & Aggregation ASM config policy

March 30, 2000IRTF Meeting - AAAARCH RG11 Open Issues Accounting policy format/language  policy, snmpconf, ipsp WGs, PAX PDL ? Session definition –Which messages indicate session start and session end ? –Sub-Sessions Mapping user/customer ID and flow Authorization negotiation –What happens if required accounting service cannot be provided Because meter cannot meter required values Meter overloaded Authorization fails (home AAA not allowed to access detailed information)  denial of service provisioning or negotiation of lowest common denominator ? Does AAA touch AccRecords or just forwards it ? –Add session ID, user ID, aggregate records Session/Auditing ID to correlate AAA data

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