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

2 VeriSign Proprietary and Confidential The CRX Model

3 VeriSign Proprietary and Confidential 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

4 VeriSign Proprietary and Confidential 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)

5 VeriSign Proprietary and Confidential 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.)

6 VeriSign Proprietary and Confidential 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.

7 VeriSign Proprietary and Confidential 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

8 VeriSign Proprietary and Confidential Recommendations (continued) + Define a process for Rate Plan Exchange ▪ Eliminate ambiguous interpretations – Example: Does $1 per MB mean $ 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

9 VeriSign Proprietary and Confidential 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