RTC-Call-Monitor

About

RTC-Call-Monitor is a tool to detect an active UDP based voice/video call by:

• Monitoring the rate of incoming/outgoing UDP packets from your machine's IP address.
• Checking the source/destination address against known network blocks for the major voice/video conference providers.

When an active call is detected, will invoke a webhook for the start and end of a call.

Supported Providers

• Zoom
• Microsoft Teams
• WebEx
• Slack
• Google Meet
• GoTo Meeting

Additional providers can be added by modifying the configuration file. See Adding new providers below.

Consolidating subnet ranges (optional): python .\consolidate-ips.py --input "D:\Downloads\ZoomMeetings.txt"

Getting Started

Prerequisites

• .NET 5.0 SDK

Minimal Configuration

Before starting the application for the first time, modify the value for LocalNetwork in appsettings.json with the details of your local network. The value is in CIDR Notation.

Most users will have a network configuration similar to the following:

  IP Address:  192.168.1.100
  Subnet Mask: 255.255.255.0

The configuration will be

"LocalNetwork": "192.168.1.0/24"

Build/Run

RTC-Call-Monitor requires that your console has elevated privileges in order to monitor network traffic.

Windows: Open a new Powershell or command prompt using Run as Administrator

cd src
dotnet run

Linux/macOS:

cd src
sudo dotnet run

Additional Configuration

Webhooks

All webhooks are HTTP POST requests and require a valid URL.

Call Start

CallStart in appsettings.json

POST body included when calling the webhook

{
  "provider": "slack"
}

Call End

CallEnd in appsettings.json

POST body included when calling the webhook

{
  "duration": 123
}

duration is the call length in seconds.

Adding new providers

The configuration key KnownNetworks is a JSON dictionary with the key being the provider name, and value is an array of CIDR network blocks. To add a new provider, add a new key/value pair to KnownNetworks.

Adding new network blocks

If the application is not detecting the start of your call, the most likely reason is that the IP address is not in a known network block for your provider. To see the destination address of your call provider, enable debug logging.

In appsettings.json: "RtcCallMonitor": "Debug"

In the console a message similar to the following will show in the console:

Unmapped network 66.77.89.91 count 122

Find your provider in appsettings.json and add a new entry for the network block

66.77.0.0/16

Restart the application and your call should be detected.