VOS3000 Billing Free Time Powerful Duration Shaving Configuration
Understanding VOS3000 billing free time is essential for carriers who want to run “first X seconds free” promotions or adjust call durations before billing calculation. The SERVER_BILLING_FREE_TIME parameter in VOS3000 subtracts a configurable number of seconds from every CDR duration, effectively offering callers a free window before metered billing begins. Need help configuring this on your switch? Reach out on WhatsApp: +8801911119966 for expert assistance.
This powerful feature, documented in ยง4.3.5.1 of the VOS3000 server manual, allows providers to shave off seconds from the recorded call duration before the billing engine applies rates. Whether you operate in per-minute or per-second billing mode, the free time deduction happens first, fundamentally changing how revenue is calculated on every single call.
Table of Contents
How VOS3000 Billing Free Time Works
The SERVER_BILLING_FREE_TIME parameter defines how many seconds are subtracted from the raw CDR duration before any rate calculation occurs. For example, if a call lasts 66 seconds and SERVER_BILLING_FREE_TIME is set to 6, the billing engine sees only 60 seconds. This mechanism enables carriers to market “first 6 seconds free” promotions without creating complex rate tables.
| ๐ Parameter | ๐ Value |
|---|---|
| Parameter Name | SERVER_BILLING_FREE_TIME |
| Manual Section | ยง4.3.5.1 |
| Data Type | Integer (seconds) |
| Default Value | 0 (disabled) |
| Scope | System-wide (all calls) |
| Effect | Subtracts X seconds from CDR duration before billing |
VOS3000 Billing Free Time Calculation Examples
Let us examine how VOS3000 billing free time impacts real-world scenarios. The deduction is applied before the billing mode determines the billable units, so the interaction between free time and billing mode is critical to understand.
| ๐ Raw Duration | ๐ Free Time (6s) | ๐ Billed Duration (Per-Minute) | ๐ Billed Duration (Per-Second) |
|---|---|---|---|
| 5 seconds | 6 seconds | 0 minutes (no charge) | 0 seconds (no charge) |
| 12 seconds | 6 seconds | 1 minute | 6 seconds |
| 66 seconds | 6 seconds | 1 minute | 60 seconds |
| 125 seconds | 6 seconds | 2 minutes | 119 seconds |
| 366 seconds | 6 seconds | 6 minutes | 360 seconds |
Impact on Per-Minute vs Per-Second Billing Modes
The VOS3000 billing free time parameter interacts differently with per-minute and per-second billing modes. Under per-minute billing, the shaved duration is first reduced, then rounded up to the next full minute. Under per-second billing, the remaining seconds after deduction become the billable duration directly. This distinction can have significant revenue implications at scale.
| ๐ Billing Mode | ๐ Free Time Effect | ๐ Revenue Impact |
|---|---|---|
| Per-Minute (1/1) | Deduct then round up to full minute | High impact โ short calls may become free |
| Per-Minute (60/60) | Deduct then round up to full minute | Moderate โ same rounding after deduction |
| Per-Second (1/1) | Deduct exact seconds from duration | Precise โ exact second-by-second deduction |
| Per-Second (6/6) | Deduct then round to 6-second blocks | Moderate โ block rounding after deduction |
Need guidance choosing the right billing mode with free time? Contact us on WhatsApp: +8801911119966 for personalized configuration support.
Why Carriers Use VOS3000 Billing Free Time
Carriers deploy VOS3000 billing free time for several strategic reasons. The most common use case is promotional marketing โ offering the “first 6 seconds free” attracts price-sensitive customers and differentiates your service in competitive wholesale markets. Beyond promotions, free time also compensates for call setup and post-dial delay, ensuring customers are not billed for time spent establishing the SIP session.
| ๐ Use Case | ๐ Typical Free Time | ๐ Reasoning |
|---|---|---|
| Promotional Campaign | 6 seconds | “First 6 seconds free” marketing hook |
| Post-Dial Delay Compensation | 3-5 seconds | Skip billing during call setup time |
| Short Call Filtering | 10 seconds | Eliminate billing for failed/short calls |
| Competitive Wholesale Rate Matching | 1-6 seconds | Match competitors’ effective rate structure |
| Ringing Time Exclusion | Varies | Do not charge for ringing before answer |
Configuring SERVER_BILLING_FREE_TIME Step by Step
Setting up VOS3000 billing free time requires modifying the server billing parameters through the VOS3000 management interface. The parameter is system-wide, meaning it applies to all calls processed by the server. Navigate to System Settings โ Billing Parameters โ SERVER_BILLING_FREE_TIME and enter the desired number of seconds.
| ๐ Step | ๐ Action | ๐ Details |
|---|---|---|
| 1 | Log in to VOS3000 Admin Panel | Use admin credentials with billing config rights |
| 2 | Navigate to System Settings | Go to Billing Parameters section |
| 3 | Locate SERVER_BILLING_FREE_TIME | Find parameter under ยง4.3.5.1 settings |
| 4 | Set value in seconds | Enter integer value (e.g., 6 for 6 seconds free) |
| 5 | Save and restart billing service | Apply changes and restart the billing engine |
| 6 | Verify with test CDR | Make test call and check CDR for deducted duration |

Revenue Impact Analysis with VOS3000 Billing Free Time
Understanding the revenue impact of VOS3000 billing free time is critical before enabling it system-wide. Even a small deduction of 6 seconds per call can reduce revenue by 5-10% on short-duration traffic. The table below shows estimated revenue changes based on average call duration and free time settings at a $0.01/minute rate.
| ๐ Avg Call Duration | ๐ Free Time = 0s | ๐ Free Time = 6s | ๐ Revenue Loss |
|---|---|---|---|
| 30 seconds | $0.01 | $0.01 (24s โ 1min) | 0% (per-min rounding) |
| 60 seconds | $0.01 | $0.01 (54s โ 1min) | 0% (per-min rounding) |
| 66 seconds | $0.02 | $0.01 (60s โ 1min) | 50% |
| 180 seconds | $0.03 | $0.03 (174s โ 3min) | 0% (per-min rounding) |
Common VOS3000 Billing Free Time Mistakes
Many administrators make preventable errors when configuring VOS3000 billing free time. The most dangerous mistake is setting free time too high for per-minute billing, which can eliminate revenue on short calls entirely. Another common error is forgetting that free time is system-wide and cannot be applied per-client or per-prefix without workarounds.
| ๐ Mistake | ๐ Consequence | ๐ Prevention |
|---|---|---|
| Setting free time too high (30s+) | Massive revenue loss on short calls | Keep below 10 seconds; test with sample CDRs |
| Not restarting billing service | Changes do not take effect | Always restart after config changes |
| Ignoring per-minute rounding interaction | Unexpected revenue drops | Model billing mode interaction before enabling |
| Applying to all traffic uniformly | Free time given where not intended | Monitor CDRs per client after enabling |
Related Resources
- ๐ VOS3000 Billing Precision
- ๐ VOS3000 Billing System
- ๐ How to Backup and Restore VOS3000 MySQL Database
- ๐ฅ VOS3000 Official Downloads and Documentation
Frequently Asked Questions About VOS3000 Billing Free Time
What is SERVER_BILLING_FREE_TIME in VOS3000?
SERVER_BILLING_FREE_TIME is a system-wide billing parameter in VOS3000 that subtracts a specified number of seconds from every CDR call duration before the billing engine calculates charges. When set to 6, for example, a 66-second call is billed as if it lasted only 60 seconds. This feature is commonly used by carriers to offer promotional “first X seconds free” deals or to compensate for post-dial delay and call setup time that should not be charged to the customer.
Does VOS3000 billing free time apply per client or per vendor?
No, the SERVER_BILLING_FREE_TIME parameter applies system-wide across all calls processed by the VOS3000 server. It cannot be configured individually per client, per vendor, or per prefix through this parameter alone. If you need different free time values for different clients, you would need to adjust your rate tables or use prefix-based billing strategies to achieve an equivalent effect. Always test configuration changes with sample calls before deploying to production.
How does free time interact with per-minute billing in VOS3000?
Under per-minute billing mode, VOS3000 billing free time is deducted from the raw CDR duration first, and then the remaining duration is rounded up to the next full minute for billing. This means a 66-second call with 6 seconds free time becomes 60 seconds, which rounds to exactly 1 minute. However, a 65-second call with 6 seconds free becomes 59 seconds, which still rounds up to 1 minute, resulting in the same charge as without free time in many cases.
Can I set different free time values for different routes?
The standard SERVER_BILLING_FREE_TIME parameter does not support per-route configuration since it is a global server setting. However, you can achieve similar results by creating separate rate plans with adjusted per-minute rates that effectively account for the free time, or by using prefix-based billing rules. For complex multi-route free time requirements, consult with a VOS3000 specialist who can design a billing architecture that meets your needs. Contact us on WhatsApp: +8801911119966 for help.
What happens if free time exceeds the call duration?
If the SERVER_BILLING_FREE_TIME value is greater than or equal to the actual CDR duration, the billed duration becomes zero, and the call is not charged at all. For example, a 5-second call with 6 seconds of free time results in a negative adjusted duration, which VOS3000 treats as zero billable time. This is why setting free time too high can be financially dangerous, especially on networks with a high percentage of short-duration calls under 30 seconds.
Is VOS3000 billing free time visible in CDR records?
The CDR record in VOS3000 typically shows the raw call duration, not the duration after free time deduction. The billing engine applies the free time subtraction internally during rate calculation. To verify that free time is working correctly, you must compare the raw CDR duration with the billed amount and confirm the math matches the expected deduction. Using the VOS3000 monitoring tools can help you track these discrepancies effectively.
How do I disable VOS3000 billing free time?
To disable VOS3000 billing free time, simply set the SERVER_BILLING_FREE_TIME parameter back to 0 (zero) in the system billing parameters. When the value is 0, no seconds are subtracted from CDR durations, and billing is calculated on the full raw duration of every call. After changing the value, you must restart the billing service for the change to take effect. Always verify by placing a test call and checking the resulting CDR and billed amount.
Get Professional Help with VOS3000 Billing Free Time
Configuring VOS3000 billing free time correctly is crucial for protecting your revenue while offering competitive promotions. A misconfigured free time setting can silently erode profits across millions of calls. Our team of VOS3000 specialists can help you design, test, and deploy the right free time configuration for your business model.
Contact us on WhatsApp: +8801911119966
Whether you need to set up a “first 6 seconds free” promotion, compensate for post-dial delay, or analyze the revenue impact of duration shaving on your traffic, we provide expert guidance tailored to your VoIP operation. Do not let billing misconfigurations cost you money โ reach out today for a consultation.
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