How NetUse collects data

NetUse utilizes the SNMP feature of modern routers. Most modern routers ( like airport extreme, time capsule, various models of NetGear and Cisco) collect and store network usage statistics. The size of “a buffer” where the usage data gets stored varies from one manufacturer to another but in general it’s not very big. NetUse accesses and counts data reported back from your router or gateway and produces realtime stats as well as stores it locally on your mac.

It’s important to understand that NetUse relies on this data and uses wherever values it gets back from your router. Some routers are known to report double  amount of usage. This is a bug in router’s firmware, not in NetUse. Please contact us if you encounter such behavior with detailed info about your router model.  Starting with NetUse 1.2.0 we include this information to the app updates to compensate for bogus router firmares till manufactures fix it. Also we’ve included a special plist value you can use to quickly fix the “double traffic” issue.

Another important aspect is a network interface NetUse uses to collect usage data from. All routers have completely different list of interfaces ( we’ve seen routers with up-to 21 interface). NetUse should be used on a physical interface connected directly to the Internet in order to get proper readings. If you use Apple’s routers ( for instance airport extreme) and DSL connection to the Internet - NetUse will automatically detect proper network interface to use and you should be good to go. However when a router connected to the Internet via cable modem or a similar type of connection current version of NetUse requires manual interface selection. Below are a couple examples to help in selecting a proper interface:

Airport Extreme 3th generation, Airport Express 802.11n and Time Capsule 2nd generation - select gec0 interface

Airport Extreme 5th generation - select mgi1 interface

The above examples do show proper reading in our tests, however you might need to try a different interface to get accurate readings. We strongly suggest to download our free SNMP test utility and play with different settings if you’re not sure what interface to choose or would like to know if NetUse will work in your network setup. If you need any help or have any question, please contact us.

13 Comments

  1. Geoff Sim says:

    Excellent utility, although multiple instances or a drop down of targets would be great.

  2. GrAnD says:

    We have plans to expand NetUse functionality to support multiple devices and interfaces.

  3. Bob Watkins says:

    Any idea how big the internal buffer is on 4th-generation Time Capsules? I’m curious how long NetUse can be paused (for example, if the computer goes to sleep) without losing data.

  4. GrAnD says:

    Time Capsule (as many other routers) uses 32bit counters which makes it 4Gb. NetUse reads these counters upon startup.

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