---
title: Bandwidth quotas and add-ons
description: How NexCMP meters traffic per service from CloudStack statistics, default quotas, 80% and 100% alerts, overage actions and add-ons.
url: https://nexcmp.com/docs/catalog/bandwidth/
applies_to: NexCMP 1.6.1
updated: 2026-11-02
---

# Bandwidth quotas and add-ons

> **Where in the admin:** Services › Bandwidth: Summary (`/bandwidth`), Add-on (`/bandwidth/addons`) and Quotas, pricing & policy (`/bandwidth/policy`). The module switch is in System › Admin › License & updates.

## What it does

Bandwidth gives every metered service a monthly traffic **quota**. NexCMP measures usage, warns the customer at 80% and 100%, and, when the quota is exceeded, acts according to your **overage policy**. Customers can buy **add-ons** of extra terabytes from their wallet; you can also grant add-ons for free.

| Service | Quota |
|---|---|
| Virtual Machines | Per VM per month (default 2048 GB, that is 2 TB) |
| Kubernetes | The VM quota multiplied by the number of workers |
| Object Storage | Download traffic per customer per month (default 100 GB); beyond it the normal pay-as-you-go price applies |
| VPN | Keeps the quota of its plan; upgrade bandwidth on the VPN page |
| Private Cloud | **Unmetered** |

## Requirements

| Item | Requirement |
|---|---|
| Module | **Bandwidth** is on by default. Turn it off under License & updates to hide it. |
| Measurement source | With the default source, **CloudStack VM statistics**. Keep VM statistics collection enabled in CloudStack; the default retention of 720 minutes is enough. |
| Proxmox VE | VMs on Proxmox VE are **not metered**. |
| Exchange rate | The add-on price is entered in VND. See [Currency and exchange rates](https://nexcmp.com/docs/catalog/currency-and-exchange-rates/). |
| Depends on | [CloudStack](https://nexcmp.com/docs/infrastructure/cloudstack/) for VM and Kubernetes traffic, [S3](https://nexcmp.com/docs/infrastructure/s3/) for storage downloads. |

## Prepare the infrastructure

Not required beyond CloudStack being connected. NexCMP reads `listVirtualMachinesUsageHistory` for all VMs of the account in one call, every 5 minutes, in windows of at most two hours. Each sample covers one minute and is **added up**. Samples are taken three minutes in the past so they have time to arrive. A gap longer than CloudStack's retention (about 12 hours) is skipped and recorded.

::: info What the numbers mean
Usage is counted on each VM's network interface, so it includes traffic between VMs, not only traffic to the Internet. It can be a little higher than an edge router would count.
:::

## Connect in NexCMP

1. Open **Services › Bandwidth › Quotas, pricing & policy**.
2. Set the values and click **Save**; a reason is asked and recorded. The worker applies the change within about 30 seconds.

   | Field | Default | Meaning |
   |---|---|---|
   | Enable Bandwidth (customer menu and buying add-ons) | on | The switch for the module's sales side. |
   | VM, GB/month (Kubernetes = this value × workers) | 2048 | Quota per VM per period. |
   | S3, GB download/month per customer | 100 | Beyond it normal S3 pay-as-you-go applies. |
   | Quota direction (VM, Kubernetes) | In + out | Or **Outbound only**. |
   | +1 TB price (VND) | 100,000 | Converted to cents at the quote rate. |
   | Max per purchase (TB) | 50 | |
   | Overage policy | suspend | **notify**, **throttle** or **suspend** (below). |
   | Enforce actual suspend from | migration date + 24 hours | Before this date nothing is suspended; customers are only warned. |
   | Throttle rate limit (Mbps) | | Only used by throttle. |

      ![Bandwidth policy: default quotas, add-on price and overage policy](https://nexcmp.com/docs/images/catalog/bandwidth-01-policy.webp)

### Overage policies

| Policy | What happens when a service passes 100% |
|---|---|
| **notify** | The customer is notified. Nothing else. |
| **throttle** | Like notify for now: the speed limiter is not connected in this release. |
| **suspend** (default) | The VM, cluster or S3 account is suspended until the customer buys an add-on or the next period starts. Only effective from the **suspend-from** date. |

The 80% and 100% alerts (bell and e-mail) always run, once per threshold, period and service. If you unlock a service that was suspended for bandwidth while it is still over quota, the next check (within 5 minutes) suspends it again. To keep it running, **grant an add-on**.

### Watch usage and grant add-ons

Open **Services › Bandwidth › Summary**. It lists every service with its usage in the current period, quota including add-ons, remaining quota, and the 80% and 100% marks. KPI tiles show the number of services, add-ons sold in the last 30 days and the collector state (running, cursor). The **Daily** table shows the current period day by day.

![Bandwidth Summary with the collector state and usage per service](https://nexcmp.com/docs/images/catalog/bandwidth-02-summary.webp)

To give a customer room, use **Grant** on a service (an add-on of whole terabytes at no charge). Open **Add-on** for the history of purchases and grants, newest first, with a type filter.

![Add-on history showing purchases and free grants](https://nexcmp.com/docs/images/catalog/bandwidth-03-addons.webp)

### What customers see

The customer portal gets a **Bandwidth** menu with usage, remaining quota and a **buy +1 TB** action paid from the wallet (up to your per-purchase maximum). Add-ons are valid for the current period.

## Verify

1. The collector on **Summary** is running and its cursor moves forward every few minutes.
2. A VM with traffic shows usage after about 10 to 15 minutes.
3. To see the alerts, lower the VM quota to a few GB on a **test** installation and generate some traffic. Do not do this on production: the quota applies to every VM.

## Limits and notes

- Usage counts per period (a month). Add-ons and quotas apply to the current period.
- "Enforce actual suspend from" protects you from suspending customers the moment the module is first enabled.
- The throttle policy only notifies in this release.
- Changing the quota applies to every site, including reseller sites. Resellers' retail and wholesale add-on prices follow their discount or markup.
- Bandwidth for **Dedicated servers** is a separate matter; see [Dedicated servers](https://nexcmp.com/docs/infrastructure/dedicated/).

## Troubleshooting

| Symptom | Cause | Fix |
|---|---|---|
| Usage stays at zero for a running VM | The worker is stopped, CloudStack is disconnected, or VM statistics are disabled | Check `sudo nexcmp status` and **Test connection** in [CloudStack](https://nexcmp.com/docs/infrastructure/cloudstack/); enable CloudStack VM statistics. |
| Usage has holes | CloudStack retention was exceeded, or the worker was down for more than about 12 hours | Not recoverable; the gap is recorded. |
| Usage is a little higher than expected | Traffic between VMs and other interface traffic is included | Expected; explain this to customers. |
| A suspended service comes back suspended after you unlock it | It is still over quota | Grant an add-on or raise the quota. |
| Nothing is suspended although the policy is **suspend** | The suspend-from date is in the future | Set it to now (the page shows "ACTIVE" when in effect). |
| "bw_over_policy must be notify, throttle or suspend" | Invalid policy sent through the API | Use one of the three values. |
| Proxmox VMs show no usage | They are not metered | Expected. |
| Customers cannot buy add-ons | Bandwidth is switched off, or the wallet is empty | Check the switch and the wallet. |