Enterprise networks are evolving at a fast pace, and with them, so are network monitoring techniques. If you are monitoring your network with an SNMP collector, you have already realized that it’s not enough to detect and troubleshoot problems experienced by the end-users. You can read more about how the network monitoring stack has evolved over time in a previous blog post I wrote here.
Nowadays, network engineers must be aware at any time, and from any network location, about end-to-end performance metrics. Information about packet loss, network latency, and wireless signal strength is necessary to understand whether the network is delivering a good experience or causing application slowness. This information can be easily achieved with network monitoring sensors.
Working from home has its pros and cons. One of the negatives is that technical support is much more difficult. Employees working from home use their own local ISPs and each one of them uses a different modem. Chances are that they use a wireless router, which could be provided by the ISP or installed independently. Most likely, the employees need to use tools like Salesforce and Office 365, or custom applications that run either in the cloud or in a private datacenter.
When home-based employees can’t access the tools they need or experience “slowness”, they are quick to open a ticket with technical support. The environmental variables mentioned above make troubleshooting difficult. The main problem is the lack of visibility in the employee’s home environment. You will either guide the employee to run some tests for them (e.g. ping, traceroute) and email them the results back (if possible), or do a remote desktop session to begin troubleshooting.
Recently our team received word that several clients in a classroom where disconnecting while doing online benchmark tests. The clients will rename nameless but were of the “lower end” variety. These clients were single band 802.11n devices which have had a bad track record of reliability, no matter what the wireless environment has been. In this particular case there were roughly 20 of these devices deployed in a classroom each with its own 2nd grader. We had been called to this classroom previously but found no issue with the network. Our laptops had performed flawlessly while accessing the same websites and never had trouble with being disconnected from the network unlike our “lower end” counterparts. Checking the controller showed no issues with channel utilization, retries, or a configuration issue. Sometimes a simple “it’s not the network” isn’t good enough and this was one of those times. We needed data, and we needed it from a client’s perspective.
Like most of you, my home network is equipped with only one wireless router, which is located in the living room. As result, some areas of my house, like my bedroom and studio, are not covered very well by the wireless signal of this single router. Frustrated by the poor quality of my video streaming, I decided last week to purchase a wireless repeater to extend the wireless signal to where it was most needed.
I bought a dual mode wireless extender that can support 2.4GHz and 5.0GHz. The setup was quite easy – it only took me a few minutes to configure the extension of my dual-mode wireless network with the WPS button. I decided to test the bandwidth speed improvements with Iperf using my NetBeez agents.
NetBeez captures network and application performance from the user perspective on wired and wireless networks. Sensors at each network location run tests and simulate the user experience. We have dozens of demo NetBeez agents deployed around the country and the world and we collect some interesting data. Here is what I discovered recently while troubleshooting a NetBeez alert.
A typical NetBeez setup has a pair of agents, one wired and one wireless, at each office in order to capture the performance of both networks. [···]
One of the most important functions of a network monitoring tool is reporting. In a report, the performance and status of any monitored resource, service, or device, for which data can be stored in a database as a time series, can be analyzed and compared with other resources to discover trends, patterns like daily, weekly or monthly fluctuations, or spot underperforming assets. Thanks to reports, you can review graphs, tables, and charts related to network availability and application performance and have a clear view of the status and performance of network and applications.
The Highly Optimized Radio Scanning Tool (HORST) is a lightweight IEEE802.11 WLAN analyzer. It was build for troubleshooting WLAN networks, and although it’s not as advanced as other tools (Kismet, Wireshark, tcpdump) it’s very easy to use, free, and can run very efficiently even on a Raspberry Pi.
For the installation and usage details, please see HORST on GitHub.
If you attended WLPC 2017, you have an Odroid that has HORST preinstalled and a USB WiFi Module. (Thanks to WLPC and Jerry Olla for the excellent Maker Session!) You are ready to run HORST! Just log in and type horst. In general, you should be able to install HORST on any Linux Single Board Computer (SBC). [···]
SSID hopping enables a wireless monitoring sensor to sequentially test different wifi networks in a round robin fashion. This strategy is very useful when you don’t want to deploy a dedicated sensor for each network available at one location. With the proper configuration, the same sensor will continuously cycle through multiple SSIDs. It will connect to the first one, execute monitoring tests, move on to the next SSID, and then repeat this sequence over and over. The benefits of SSID hopping include detection of problems with AP association, radius authentication, and DHCP addresses availability. On top of that, you can run network and application monitoring tests as usual.
On Thursday, February 23rd, I will present at the WirelessLAN Professional Conference on how to Turn your Odroids or Raspberry Pis into Remote WiFi Monitoring Sensors. This is part of the WLPC TEN talk series, in which presenters have ten minutes for their talks. It takes less than ten minutes for me to set up and connect an Odroid or a Raspberry Pi to the NetBeez dashboard, and this post will help all you WLPC attendees follow along more easily. [···]
What differentiates good Internet Service Providers (ISP) from bad ones? Whether or not they meet their service level agreements (SLA). An SLA is a contract between a service provider and a subscriber that defines what level of performance is expected from the service provider. An ISP that doesn’t respect their SLA will deal with angry customers, have subscribers switch to other competitors, or, worse, deal with lawsuits. [···]