Charging Session Calculator
Estimate online charging TPS, daily CDR volume and mediation storage for a subscriber base.
About Charging Session Calculator
Charging load is driven by event count rather than bandwidth. Concentrating the busy-hour fraction of the daily events into 3600 seconds gives the sustained credit-control rate, and the same event count multiplied by record size and retention gives the mediation platform's disk bill. An OCS that cannot keep up either blocks revenue-generating sessions or, worse, lets them run unrated, and CDR storage growth is one of the most commonly under-budgeted lines in an operator's OSS.
Formula
Charging Session
busy-hour TPS = (subscribers × events per day × busy-hour share) ÷ 3600; storage = events per day × CDR size × retention.
- busy-hour share
- Percentage of the day's events that land in the peak hour
- CDR size
- Average encoded record length including headers
Worked example
With the default values below, Charging Session Calculator returns Busy-Hour Charging Rate of 4,000. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Subscribersaccepts 1–200,000,000 subscribers
- 3,000,000 subscribers
- Chargeable events per subscriber per dayaccepts 1–2,000 events
- 40 events
- Average CDR sizeaccepts 50–20,000 bytes
- 500 bytes
- Share of events in the busy houraccepts 1–100 %
- 12 %
- Rated capacity per charging nodeaccepts 50–500,000 TPS
- 3,000 TPS
- CDR retention periodaccepts 1–3,650 days
- 90 days
Results
- Busy-Hour Charging Rate
- 4,000 TPS
- CDRs Generated per Day
- 120,000,000
- Mediation Storage per Day
- 60.00 GB
- Storage for the Retention Period
- 5.40 TB
- Charging Nodes Required (N+1)
- 3
Step by step
- 1Values used
- 2Charging Session
- 3Busy-Hour Charging Rate= 4,000 TPS
- 4CDRs Generated per Day= 120,000,000
- 5Mediation Storage per Day= 60.00 GB
- 6Storage for the Retention Period= 5.40 TB
- 7Charging Nodes Required (N+1)= 3
Assumptions and limits
- The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation or tax into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Charging Session calculated?
busy-hour TPS = (subscribers × events per day × busy-hour share) ÷ 3600; storage = events per day × CDR size × retention. Charging load is driven by event count rather than bandwidth. Concentrating the busy-hour fraction of the daily events into 3600 seconds gives the sustained credit-control rate, and the same event count multiplied by record size and retention gives the mediation platform's disk bill.
Why does Charging Session matter?
An OCS that cannot keep up either blocks revenue-generating sessions or, worse, lets them run unrated, and CDR storage growth is one of the most commonly under-budgeted lines in an operator's OSS.
What values do I need to enter?
This calculator takes 6 inputs: Subscribers, Chargeable events per subscriber per day, Average CDR size, Share of events in the busy hour, Rated capacity per charging node, CDR retention period. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.