Billing & Invoices

1. Real-Time Billing Flow

When each call ends, Wholesale automatically:

Call Ends
  │
  ▼
Calculate Charge (sell price)
  │
  ├── Write to wholesale_cdrs
  ├── Deduct tenant balance (SQL: balance = balance - price)
  ├── Report to circuit breaker (success/failure)
  ├── Record sliding window event (ASR/ACD)
  └── Report Prometheus metrics

1.1 CDR Fields

2. CDR Query

Wholesale → CDR Management:

Supported filters:

• Time range
• Tenant
• Trunk
• Caller / Callee
• Answered / Unanswered
• SIP status code

2.1 CDR Export

Async export flow:

1. Create an export task (wholesale_export_tasks table)
2. Background worker streams gzip CSV generation
3. Download from the Export Tasks list when complete

2.2 CDR Recalculation (Rebill)

CDR Management → Rebill: Recalculate historical CDRs after modifying rates.

• Filter by time range and tenant
• Recalculate using current rate decks
• Update CDRs and tenant balances

3. Billing Cycles

3.1 Configuration

Tenant Details → Billing Settings:

3.2 Invoice Generation

A background task checks hourly:

1. Finds billing cycles due for settlement
2. Aggregates CDRs within the cycle
3. Generates wholesale_bills records:
   • Total amount, call count, ASR, total duration
   • Bill status: draft → confirmed → paid

3.3 Invoice Operations

4. Top-Up & Balance Management

Tenant Details → Top Up:

• Amount
• Payment proof image (uploaded to local server or S3)
• System logs to rustpbx_recharge_logs

Tenant Details → Generate Invoice:

• Manually trigger invoice generation for the current period

5. Database Requirements

Wholesale billing involves significant concurrent writes. Database requirements:

CDR Data Growth Estimate:

• 1 CDR per call ≈ 1KB
• 100K calls/day ≈ 100MB/day ≈ 3GB/month
• Recommend monthly partitioning or periodic archiving for the wholesale_cdrs table