Policy-based Accounting

Policy-based AccountingPolicy-based Accounting

Tanja Zseby

GMD FOKUS - German National Research Institute for Information Technology

Competence Center Global Networking (GloNe)

http://www.fokus.gmd.de

January 24-26, 2000 Merit Consortium Meeting 2

Competence Center Global Networking (GloNe)Competence Center Global Networking (GloNe)

Open Source Centre

Internet

Internet

Inte

rne

tInte

rne

tIn

tern

et

Internet

InternetIn

tern

etInternet

Internet

Internet

Internet

MultimediaApplications

GroupCommunication

QoSModules

FlowTreatment

GenericCharging

IPTel2000

CO

ST

263

- Q

ualit

y of

futu

re

Inte

rnet

Ser

vice

s

QofIS2000

GI (

KuV

S),

NE

C,

Uni

. Kar

lsru

he, M

CI

Active Internet Lab:

MINT, QIPTel in DS, CADENUS, ...

BANG, RealCast, CADENUS, ...

Susie, IPMM, Quasimodo, AAA

Discman, T-Nova, ...

Discman, CADENUS, QIPTel in DS, ...

BANG, Discman, CADENUS, QIPTel, ...

infrastructureinfrastructure

pro

jects

pro

jectse

ven

tseven

ts


GMD Charging and Accounting ProjectsGMD Charging and Accounting ProjectsInternational 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


OverviewOverview

• 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


Charging and Accounting for IPCharging 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 ?


Future Service Provider OptionsFuture 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


Charging Schemes (Examples)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

PGuaranteed=(a⋅r +b⋅(R−r) +c⋅B) ⋅tFlowPControlled_ Load =(a⋅r +b⋅(p−r)⋅ f +c⋅B)⋅tFlow

Crt =L ⋅ b⋅P(B)+c⋅P(C) +d⋅P(D)( )hops∑ +K(rt)⋅h⋅V

Cnrt=K(rt) ⋅h⋅V


Tariff VariablesTariff Variables

Access-line speedBuffer occupancy

Flatrate Resource-based Tariffs Congestion-based Tariffs

QoS DimensionsUsage Dimensions

Reservation Parameters Profil ParametersVolume Time

Hop Count

Tariff Components

Packets involved

Zone

Distance

Geographical Distance


Service and Tariff ExamplesService and Tariff Examples



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)



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


Real-Time Traffic Flow Measurement (RTFM)Real-Time Traffic Flow Measurement (RTFM)

Meter

MeterReader

Manager

Analysis Application

Configuration

Usage Data

Control

Usage Data

RTFM• IETF working group (inactive)

• RFCs 2720-2724

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


Policies at Different LayersPolicies at Different Layers

Accounting LayerAccounting Configuration

(e.g. inter-domain agreements)

Accounting Policy

Charging specific requirements

Charging LayerCharging Configuration

(e.g. charging formula)Charging Policy

User/Service specific requirements

Charged data

Metering LayerMeter Configuration

(e.g. classifier rules, metering intervals)

Metering PolicyCI

PICollecting

requirements

DI

Collecting LayerCollecting Configuration

(e.g. meter location)Collecting Policy

Accounting requirements

Billing LayerBilling 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 80301 “Parameters and Mechanisms for Charging in IP based Networks”


Policy-based Accounting ArchitecturePolicy-based Accounting Architecture

Provider Domain A Provider Domain B

Accounting

Collecting Collecting

Billing

Charging

PIP NAR

AccountingData

Billing andChargingPolicyServer

Accounting& MeteringPolicy Server

AccountingPolicy

M

Meter Policy

ChargingPolicy (TFL)

BillingPolicy

Account.Policy

ReaderPolicy

PIP NARAccounting

M

MM


Premium IP Network Accounting RecordPremium 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 80301 “Parameters and Mechanisms for Charging in IP based Networks”

•ADIF description of Elements•ADIF-to-PIPNAR converter

16Merit Consortium MeetingJanuary 24-26, 2000

# setup chargesc = 0.5# volume unit in bytesvu = 800000# price per volume unitpv = 0.5# time unit in secstu = 100# price per time unitpt = 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 formulap = sc + (v/vu)*pv + (t/tu)*pt

TFL: Tariff Formula Language 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


Exchange of Tariff InformationExchange 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 mode Pull mode


Online ChargingOnline Charging

PlotPrices

t

p

Collector

NAR

Price Calculation

Tariffs (TFL)

Meter


Tariff Comparison Tariff Comparison


AAA Server with Accounting as Separate ServiceAAA Server with Accounting as Separate Service

Generic AAA serverRule based engine

Application SpecificModule

Policy

Events2

1 1

3

AccountingModule

Service

5

Metering

6

Acct Data3

2


AAA Server with Accounting as Part of the ServiceAAA Server with Accounting as Part of the Service

Generic AAA serverRule based engine

Application specificModule

Policy

Events2

1 1

3

Accounting/Metering Service

5

Acct Data3

5


Example: Interaction with AuthorizationExample: Interaction with AuthorizationUser

AAA Server AAA Server

Service Equipment

Visited ISP Home ISP

Collectors

Meters

AccountingRecords (ARs)

1

2

3

4

5

6

Service parametersincluding Accounting Policy

Charging Policies

Bill Charging & Billing

configuration

7

ARs8

ARs

(optional online charging)


Multicast AccountingMulticast 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


Cost Sharing [Herzog]Cost Sharing [Herzog]

R2

I

R1

PA

TH

+ [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]R

ES

V +

[N

3=N

1+N

2]

N1, N2: Number of receivers at node R1,R2 N3: number of upstream receivers C(X,Y): costs for transport between X,Y


The Chuang-Sirbu LawThe Chuang-Sirbu Law

from[ChSi98]

• Lmc Luc · N0.8

• Flat rate for dense mode

• Pmc = Puc· N0.8 for sparse mode


ConclusionConclusion

• 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: http://www.fokus.gmd.de/glone/ http://www.fokus.gmd.de/glone/research/genca/


Call for PapersCall 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, 2000

http://www.fokus.gmd.de/events/

Policy-based Accounting

Documents

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