Charging Session Calculator
Estimate online charging TPS, daily CDR volume and mediation storage for a subscriber base.
Inputs
Busy-Hour Charging Rate
4,000TPS
CDRs Generated per Day
120,000,000
Mediation Storage per Day
60.00GB
Storage for the Retention Period
5.40TB
Charging Nodes Required (N+1)
3
Step by step
Values used
Subscribers = 3,000,000 subscribers; Chargeable events per subscriber per day = 40 events; Average CDR size = 500 bytes; Share of events in the busy hour = 12 %; Rated capacity per charging node = 3,000 TPS; CDR retention period = 90 days
Charging Session
busy-hour TPS = (subscribers × events per day × busy-hour share) ÷ 3600; storage = events per day × CDR size × retention.
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
How it works
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
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.