Keys to Avoiding Contention

New applications like VoIP and web-based SaaS apps demand robust and reliable bandwidth. The increased use of applications like video conferencing, web-based programs, and VoIP is pushing contention to the forefront as a common cause of delay.

Network contention occurs when an application’s bandwidth use spikes to the point of interfering with the performance of other applications on the network pipe. Communications and web-based applications often require high and consistent network bandwidth to avoid these interruptions, which immediately impact user experience.

Pinpointing Contention Causes

To identify points of contention, first look at overall bandwidth utilization and utilization per application. The key is to identify whether applications are consuming more bandwidth than expected. Once the offending application has been identified, identify top talkers using the application. The final step is to look into IP Pairs to identify conversations consuming the most bandwidth. From this information, you can identify not only the offending culprit and cause, but whether the contentious traffic is legitimate. For example, if the contentious application is a back-up mistakenly occurring during work hours or misconfigured QoS settings, you can identify this from looking at utilization trends and then drilling into specific applications and users.

Here are three keys for avoiding contention issues that could plague your next roll out.

Pre-Deployment Assessments

Because of the challenges inherent with UC applications, understanding your basic network environment is vital to ensuring a successful roll out. Conducting a site survey before installing UC services can identify and eliminate many performance problems before deployment.


Regularly monitor performance to establish expected application performance and normal network activities. Run weekly and monthly comparison reports to pinpoint slowly degrading applications. Configure alarms for instant notification of performance anomalies.

QoS and Precedence

When implementing communication or collaboration applications, QoS is mandatory for ensuring adequate bandwidth. Configure precedence settings appropriately for all application components. A frequent mistake is to leave out or misconfigure precedence for portions of an application, which then results in contention.

This article was published by Network Instruments

Hidden IPv6 Security Threats

According to the North American IPv6 Task Force over half of U.S. CIOs have IPv6 traffic on their networks, and are not aware of it.  While you may not be aware of IPv6 hackers are fully aware.  IPv6 traffic can be tunneled over IPv4 connections and be reported as normal IPv4 packets unless you have deployed security and monitoring tools that can inspect tunneled traffic.  Here are some key steps to prevent the threat:

  • Verify your firewalls, intrusion detection, and network monitoring solutions are IPv6-aware
  • If not running IPv6, ensure all equipment has IPv6 turned off
  • Consider buying firewalls and intrusion prevention products to block all IPv6 traffic
  • Develop policies for handling IPv6 traffic

A fully integrated solution like Network Instruments Observer and GigaStor provide integrated native support for both IPv6 and IPv6 tunnelling over IPv4.

You can read more about IPv6 threats in this Network World article and see how you can Configure Network Instruments Observer to show your IPv6 Traffic.

Tech Tip: Displaying IPv6 Data in Network Instruments Observer


IPv6 supports 128-bit addressing which allows for significantly longer IP addresses than with IPv4.  A question you’ll face with IPv6 is how you would like your addresses displayed.

While IPv4 is almost always displayed as a “dot-decimal” value, IPv6 can be displayed in a number of ways within Network Instruments Observer:

Compressed hexadecimal

Non-compressed hexadecimal

Compressed IPv4 compatible

Non-compressed IPv4 compatible

Decimal ‘.’ Separated

Displaying IPv6 Traffic in Network Instruments Observer