CRX Peering: Data Reconciliation

1. CRX Peering: Data Reconciliation Feb 12, 2008 CDG-IRT CRX Task Force

2. The CRX Model VeriSign Proprietary and Confidential

3. Data Reconciliation Objectives • Balance on Session Counts • Balance on Volume Usage (in bytes) • Balance on Duration (in seconds) • Balance on Calculated Charges • Feed the appropriate Financial Clearinghouse • Exceptions Handling, as needed • Reconcile Rejects • Determine out-of-balance causes • Determine %Variance • Perform manual Adjustments, if necessary VeriSign Proprietary and Confidential

4. Possible Points of Failure • Technical Data Exchange • NAS IP Address, Realms, BSID’s, MCC/MNC (Carrier_ID), MBI’s • Data Pool (UDR Accounting) • Uncorrelated Sessions (i.e. missing STOPs or “stale” sessions) • End of Day & Settlement Cut-Off • Session Start Time versus Session End Time • The “UDR Accommodation” factor • Validation (Format & Adequacy Checks) • Rating • Rate Plan (Rate precision, Rating Elements, Effective Date) • Level of Aggregation (Session-level, Monthly Carrier-level, Daily Carrier-level) • Unit of Measure (Bytes, KB, MB, or 128 Bytes, etc.) • Usage Rounding (Round versus Round-Up versus Truncate) • Tiered Pricing (Progressive / Stepped) or Bulk Discount • Calculation Rounding (decimal precision, minimum charge) VeriSign Proprietary and Confidential

5. UDR Accommodation • Why it is flawed: • It skews the true Session Count (double-counts the same Session in two Settlement periods) • To be consistent, All entities – Serve carrier, CRX’s in-between, Home carrier – must perform this; otherwise, causes out-of-balance. (*Majority of existing Data Roaming implementations do not perform UDR Accommodation.) VeriSign Proprietary and Confidential

6. Stale Session (Missing Final STOP) • This is an Exception condition • Cause for missing STOPs: Unknown • 3GPP2, WiFi/WiMax do not consider this a complete, billable Session • Revenue Loss for the Serve carrier believed to be within 2% threshold • Home carrier may choose to retail-bill based on last INTERIM update • Retail Billing is independent of Wholesale Billing in Data Roaming • This is analogous to a “dropped/incomplete” call in Voice • Some home carriers simply do not accept incomplete calls • CIBER allows a maximum elapsed time of 5 minutes • There is no guarantee that all entities (Serve carrier, CRX’s, Home carrier) receive the same number of INTERIMs • Special-Handling is costly to implement and does not fully-eliminate the chance for out-of-balance. VeriSign Proprietary and Confidential

7. Recommendations - so CRX’s can be “In-Balance” • Define a process for “electronic” Technical Data Exchange • Initial implementation of Roaming Partner “pair” • Handling subsequent updates • Allow minimum lead time for updates to take effect • Disclose “unique” set-ups – i.e. multiple carriers sharing the same network • Define uniform UDR Accounting rules and Cut-offs • To avoid implementation nightmare, do not allow Bilateral flexibility here • Peering CRX’s must have the same Data Pool as a starting point • Require Final STOP. It is the most reliable, finite end to a Session • Use Session End Time GMT as the basis for EOD/Settlement cut-off • Define consistent Validation rules • Duplicate Check criteria • Aging • Excess Duration VeriSign Proprietary and Confidential

8. Recommendations (continued) • Define a process for Rate Plan Exchange • Eliminate ambiguous interpretations • Example: Does $1 per MB mean $0.0009765625 per KB? • List acceptable Rating options, then carriers choose from that List only • Allow minimum lead time for new rates to take effect • Support of new Rating Elements should be communicated in advance, as these may require Code Development • Example: 1x versus EVDO, Zone-based, Subscriber-based, QoS • Revise the CRX File Exchange Format • Allow for multiple summary records per Roaming Partner “pair” as dictated by rate plans and/or rating elements. • Expand the List of UOM to include minimum blocks (i.e. 100KB) • Define Monthly Reconciliation Process • Adhere to file exchange due dates • Exchange Contact List, Escalation List • Variance Handling (e.g. acceptable Threshold) and Manual Adjustments VeriSign Proprietary and Confidential

9. Table for Future • Further research of “Stale” session • Possible causes and fix • Continue to monitor its occurrences as a percentage of total sessions • Quantify lost revenue in terms of usages (bytes) • Test for consistency across entities • Do all INTERIM updates make it all the way to the Home carrier? • Devise a method to special-handle, then incorporate into Data Pool • Example only: Force a STOP after 24 clock hours have elapsed from the last INTERIM update. • FCH Peering • Carrier Identifier recognized by all FCH’s • Standard FCH Feed format • Common Settlement schedule (due dates, etc.) • Settlement Funding should be transparent to the Carrier, even if its roaming partners use different FCH’s VeriSign Proprietary and Confidential