Network Troubleshooting

Network Troubleshooting

“The Internet is running slow” – a common complaint from Internet users. Some common causes of slow Internet performance are:

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  1. Problems with the ISP.
  2. Slow router or firewall.
  3. Users downloading large amounts of data.
  4. Problems with Windows.
  5. Remote sites not performing well.
  6. Denial-of-service or other kinds of attacks.

ISP Problems

There can be big differences between the speed advertised by ISPs and what they actually deliver.

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Cable companies are especially prone toward having inconsistent performance, even with “business Internet”. According to Charter Cable’s Network Management Practices:


   ”Charter advertises its speeds as ‘up to’ a specific level.”


You can easily measure your Internet performance at any given time by running an Internet Speed Test.


Unlike cable companies, there are many ISPs that offer Dedicated Internet Access with a guaranteed minimum bandwidth and SLA guarantees of performance.

Router Performance

Some ISPs offer blazing fast Internet connections – speeds that routers often cannot keep up with. Xfinity, for example, has a 2GB/sec service, and Verizon FiOS provides 1GB/sec. Here are some throughput measurements forΒ small routersΒ andΒ large routers. When looking at these measurements, it is important to keep in mind that the measurements only represent what the router can do under ideal conditions. Actual performance will be slower because of additional burdens placed on the router’s CPU. Besides basic packet switching, the CPU can be burdened with tasks such as VPN encryption, malicious traffic detection, IP address access lists, and NAT.


True gigabit performance is rarely provided by most routers, even under the best of circumstances. If you are interested in building a network with gigabit capabilities, you may want to discuss possible strategies with one of our engineers.

Traffic Prioritization

In many LANs, a single user doing a Windows update can significantly slow down the entire office. To combat this problem, many routers have a feature calledΒ Quality of ServiceΒ which prioritizes traffic so that no single user can bog down the entire LAN. This feature is sometimes also calledΒ Bandwidth Management.

Windows Problems

If just one person is experiencing Internet performance problems, it is likely that Windows has gotten bogged down. The most common solution is to re-boot the PC.

Remote Site Problems

If you suspect that a site has performance problems, the easiest thing to do is simply to compare the site’s performance with a site that is known to perform well.Β yahoo.com, for example, usually performs well. All of the Restaurant ONE websites are designed to have 75% head-room, both for the network and the server, so you should always see consistently fast download speeds from Restaurant ONE.

Malicious Internet Traffic

Every day, Internet hosts in the U.S. receive vast amounts of malicious traffic, especially from China. This traffic includes many different kinds of login attempts, spam, and even denial-of-service attacks.


Malicious traffic can cause Internet access to slow down, without any obvious reason.


In general, the better your firewall, the less you will be affected by malicious traffic. Two examples of good firewalls are the Linksys LRT214 and the TP-Link SafeStream TL-R600VPN.

Internet Monitoring

A web page is available to you from Restaurant ONE that continuously monitors Internet performance in all your locations, and in your corporate office. This gives you the ability to look retroactively at Internet performance in any location. If a user tells you, for example, that they had problems a half hour ago, you can easily check if there was an issue with the Internet at that time.


In addition, small devices are available that can plug into your LAN and give you detailed performance data both for the LAN and for the Internet.