Diameter Real-Time Credit Check and Accounting

1. Diameter Acceleration Program Interlink Networks 15 April 2002 Rich Mironov Diameter Real-Time Credit Check and Accounting

2. Agenda • Speaker introduction • RADIUS billing and credit problems • iPass RADIUS model • Diameter and Credit Control • Carrier uses • Summary

3. Rich Mironov • Principal, Mironov Consulting • Strategic product planning • Clients in wireless networking, AAA, VPN services, security appliances • Early product driver at iPass • Senior Director, Product Management • Software, billing, quality of service, security, VPN integration • Silicon Valley alumnus • HP, Tandem, Sybase

4. Disclaimer • One man’s opinion • Not representing clients or previous employers • Your input and observations requested

5. START START START STOP START STOP START START STOP STOP STOP STOP START START START STOP INVOICE PAYMENT INVOICE INVOICE RADIUS Billing History • Ground-breaking for its time • Simple service authorization • “Approved” or “Rejected” • Assumed reliable NAS behavior • Exactly one START, one STOP • No local time • Stretched beyond its design goals • Wholesaling • Remote billing systems • Complex pricing and rating • Prepaid services • Simultaneous session control

6. RADIUS Billing Challenges • START and STOP are stateless • Retry mechanism creates duplicates • Which users are currently connected? • Validity of unmatched STOPs • Workarounds for local time unreliable • Prepaid services • Pre-approve a specific amount • Real-time rating based on complex factors • Third party transactions • Service price inquiry, balance check • Refunds “!?#*”

7. iPass Model • World’s largest roaming provider • 15,000 POPs in 150 countries Provider’s NAS Customer’s AAA iPass NetServer iPass RoamServer iPass Global Transaction Centers iPass Settlement System

8. START START START START START START START START STOP STOP START STOP STOP STOP STOP STOP STOP STOP STOP STOP START START START START START START START START START START START START START START START START START START START START STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP START START START START START START START START START START STOP STOP STOP STOP STOP STOP STOP STOP STOP STOP INVOICE INVOICE INVOICE INVOICE INVOICE INVOICE INVOICE INVOICE PAYMENT PAYMENT PAYMENT INVOICE NEW CHANNEL BLOCK USER REFUND CREDIT REBILL iPass RADIUS Challenges • Millions of STARTs, STOPs • ~ 200 carriers, PTTs, ISPs • Duplicates, unmatched records, overlaps • Batch overhead • Matching, cleaning, de-duplication • No unique identifier • Concurrent session identification • Refunds and adjustments • Potential prepaid overruns

9. Diameter Credit Control Proposal • Harri Hakala, et al, March 2002 http://www.ietf.org/internet-drafts/draft-hakala-diameter-credit-control-02.txt • Proposes Diameter application for real-time cost and credit control Accounting Server Client Application Credit Control Server Service Element Service Consumer

10. request 2 min @ €1.25/min €2.50 credit hold final total €2.25 € 2.25 charge, €0.25 released New Credit Control Capabilities • Session-based (reliable Diameter transport) • Service Element sends (expected) cost • Credit Control Server approves, reserves sufficient credit • Service Element confirms final charge amount • Credit Control Server may do partial refund Service Element Credit Control Server

11. Prepaid Service Opportunities Many ways to avoid “last session overrun” model • Pre-priced services • Reserve exact credit amount • Renewable session services • Re-authorize every 90 seconds • Typical transaction price • Exact amount in final submission • One-time events charged in one pass • E-purchases, reservations, refunds, flat-rate transactions, directory assistance, driving directions…

12. More Creative Pricing • Service price inquiry and “shopping engines” • Allows complex rating and third party service delivery • “How much per unit for service-type for customer-ID via channel during time-of-day and day-of-week?” • Which remote storage service is lowest cost for 13 GB, max 10 days, encrypted, 2 MB/sec throughput? • Complex pricing • Frequent Flyer: HighUseGroup2 get first minute free • Bundling: Use service B this week and service A is free • Specials: 20% off next one or 35% off next six • Third parties subsidize service, buy on spot market

13. Benefits • More revenue, fewer write-offs • Industry estimate of 2% - 5% unbillable sessions • Recover $250k/year on $10M product line • Confirm customer’s credit status before providing service • Price inquiry allows many new rating options • Volume purchasing across providers by end customer • Time-of-day by service by customer • Vary wholesale terms by reseller by service type • Auction-style bidding • Concurrent users (Diameter) • Improves tracking of simultaneous sessions • “Shared” accounts with enforceable limits

14. Finer-Grained Policies Possible • Four subscriber groups • Corporate Platinum, corporate Gold, consumer Silver (usage-based), flat rate consumers • Session limits, simultaneous users • Platinum: unlimited, up to 20 simultaneous sessions • Gold: 4 hours weekday, unlimited weekend, single session • Silver: 1.5 hours M-F 7AM-7PM, else 3 hours. 2 simultaneous • Flat rate: 20 min M-F, 3 hours weekend, single session only • High speed access (ISDN or 802.11b QoS) • Platinum: full bandwidth at all times • Gold, Silver: 80% of max Mon-Thurs… • Need rich set of policy tools

15. Challenges • Finished applications • Current IETF draft not yet approved, implemented • Adoption • First uses will be internal to single carrier networks • Upgrade NAS, AAA, accounting, billing, SLAs • Third party services require adoption of interoperable applications

16. Summary • Reaching limits of RADIUS accounting • Diameter and Credit Check expand possibilities for service delivery, rating, billing • Adoption and deployment are next phases

17. Diameter Acceleration Program Interlink Networks 15 April 2002 Rich Mironov Diameter Real-Time Credit Check and Accounting