Tool to monitor how much Internet data devices are consuming in a home network, quota

Question

I need a network monitoring program that I can run from my computer, but that monitors my entire network for my house. My ISP imposes a data cap of 300GB per month. Due to finances some of my family members had to move in with me, and last month we exceeded the data cap. Since this is for my home, free would probably be my only option. In case it helps, my home network is composed of two hardwired Windows desktops and, on average, 5 to 7 wireless devices from phones to laptops to game consoles.

The program must be able to do the following:

1. Monitor the entire network from one Windows or Linux desktop.
2. Either send an email alert or turn off internet access for the network when a specified amount of internet data has been used. Both is preferable, but either will work independently.

There are three things that would be nice for the program to have, but are by no means requirements:

1. If the program can keep track of how much data is being used by each device, it would be nice.
2. If the program can terminate an individual wireless device's network connection after it uses a certain amount of data, it would be great.
3. If the program can put devices into a group and terminate the network connection of all devices in a group after a group has collectively used a certain amount of data, that would allow me to put each family member's devices into a group and allot each person an amount of data to use.

I realize these features are pretty much a wishlist and I probably won't find such features in a free program.

I have already tried every program on this list, but none of them did what I needed. I also have tried a program called Networx, but I have two problems with it. The first is that I feel like it is reading more data than is actually moving to and from the internet. The second is that for it to work in the situation I need it to, I would have to have it running on a computer in between my modem and my wireless router, and I don't have a spare pc to do that with. It has an option to monitor the modem directly, but I have been unable to get it to work with my modem, and I am certain it was monitoring more data than was moving to and from the internet when I tried it at a friend's house.

Answer 1

First step is to establish what control and data you have available on your modem/router - your ISP should be able to help on this but there is often the relevant information for logging on to the router on the backplane or underside of the router - some of them are very sophisticated these days. Depending on the brand you should be able to do some or all of the following but you may need to turn up the logging level for a day or two to get the information,:

• Identify which users are using the most data access on the network
• Possibly either cap or rate limit those users/machines - games consoles are often the major culprit
• Do the same for specific applications, to two major culprits are media streaming and games.

If the router does not provide the information & rules that you require you should at least be able to turn off the WiFi and connect to the ISP router by a single cable from either a bought in router/hub that does provide what you need or from a Linux machine acting as your router. If you go for the latter the machine will need at least 2 wired network connections and a wireless connection and need to be running as a network server with logging and rules in place, this is the only software solution in this answer and very generalised as to detail all of the options that this offers would be a book.

Update Note that a RaspberryPi with a WiFi dongle could act as your WiFi hub with logging and the cost would be minimal.

The last option should provide all of the capabilities that you require and the machine will be available for other tasks but would need to stay powered on all of the time, (another expense). The software to do this is free but learning to set it all up will take some time and effort - it may lead to a new career though.

Possibly the cheapest options are:

1. Pay your ISP for a plan with a bigger data allowance commercial option - possibly asking your new "guests" to contribute to the added cost.
2. Switch ISPs to get the same commercial option 2 - may even save you money
3. Watch your data usage as a household via the ISPs web pages and when it is getting very near to the cap switch off & unplug the modem likely to be unpopular Dictator Option 1
4. Warn your family members that you are doing the above and which applications are likely to push you over the limit and ask them to refrain from using them. Wetware option
5. Daily check on your usage, graph it, and warn everybody of the predicted date of the data usage reaching the limit you have set yourself for doing 3 above - e.g.: telling everybody "if you all carry on as you have been we will stop having the internet next Tuesday for the rest of the month" may have an effect. Social-ware Option
6. Turn off WiFi for specific time periods Dictator Option 2
7. Turn off WiFi altogether and inform your guests that if they need to update their phones they should find a free WiFi spot in one of the many commercial outlets that offer it. "not a mug"-ware option

Answer 2

Another option would be to take some snapshots of network traffic so as to establish most likely culprits by IP address - depending on your network configuration, operating system and hardware Scapy or Wireshark may be able to put your WiFi card into monitor or promiscuous mode. You will then be able to capture all of the WiFi traffic.

• Wireshark has a nice GUI, is simpler to install and has some nice analysis tools
• Scapy is command line/shell but you may find it easier to extract the data you need as it is all script-able in python.
• Both are available for various platforms
• Both are free
• In both cases you may or may not be able to put a specific network/WiFi card into promiscuous mode.