Policing Network Traffic
What to do when network traffic threatens service speed and quality
As an enterprise network
engineer at Ball State
University (IN), Chris Cahoe
has seen the university network
evolve into an ISP for
the front lines
at BSU, Cahoe
has wrestled with performance
problems such as
latency, packet loss, and
bandwidth issues that frustrate
users across the campus
and precipitate demands
for improved services. But
his strategies for network
optimization have allowed
the university to deliver fast,
reliable connections to
without major investments
in new infrastructure. How
does he do it? Here, Cahoe
offers his Top 10 practical
tips for better network traffic
Want to be considered for Campus Technology's Top 10? Send your countdown and a brief background/bio summary to firstname.lastname@example.org
Monitor and baseline your network; get to know it well.
- Knowing your network is the key element of a good management strategy.
- Familiarity with your network will become your best management tool.
Maintain long-term graphs of latency, jitter, and packet loss.
- Gone are the days of simply monitoring whether the network is up or down.
- Keep detailed records as proof of proper network management.
Don't allow network links to become saturated by traffic from any
single part of your organization.
- Define maximums and minimums for traffic that traverses links that have
- If links become saturated, make sure everyone gets a fair slice of the pie.
Subdivide network traffic by type of user or device.
- Create maximum and minimum throughput priorities for user groups such as
academic users, residence hall users, or data center devices.
- Make sure low-priority users can't overrun higher-priority devices and vice
versa, while competing for bandwidth to the commodity internet.
Prioritize traffic as real-time or non-real-time.
- Do not prioritize based on the perceived "importance" of the application.
- An H.264 packet that is two seconds late is useless for streaming video; an
e-mail that is two seconds late is still an e-mail!
Create contingency plans that address external outages.
- Make sure your network is multi-homed; use multiple providers.
- Be ready to alter your users' bandwidth priorities when your internet capacity
becomes drastically reduced during an outage.
Give users the option to secure their traffic over the wired and
- Encryption might not always be necessary, but make sure the capability is there.
Limit or block protocols that under normal circumstances shouldn't
- Just because the network can transmit all types of traffic doesn't mean it should.
- Bot-infected computers could be using up bandwidth you paid a pretty
Watch out for end devices with abnormally high numbers of connections
or connection rates.
- If a device has connections that number in the thousands, and it's not a server,
it's time to start placing bets on just how many viruses the device has.
Plan ahead for network growth.
- If anything is a certainty, it's that bandwidth requirements will increase
- Don't be caught off guard by next year's demands!