Day 5: How To Manage Your Bandwidth

This post continues our 20 Day Challenge to understand the technical aspects of videoconferencing.

Another key component of a quality videoconferencing is proper bandwidth management.

First Assess Your Network

• How much bandwidth are you currently using?
• Does it sometimes peak to your maximum?

A videoconference of 384K only uses about 400-500K; however, if your bandwidth is full and maxed out; the other traffic can clobber your videoconference so you have very poor quality. If your traffic EVER spikes to the max during school hours when you might have a videoconference, you need to put a solution in place to guarantee the quality of your videoconference. Here are three options:

VLANS

• Described as a virtual LAN, a VLAN consists of a group of devices/hosts that communicate as if they were on the same broadcast domain, even if not on the same physical location.
• Example: Most video networks use VLANs to keep their video traffic separate from their normal data traffic. This helps with quality and bandwidth management.

Router QoS

• Another method is to set quality of service for videoconferencing on the parts of the network that you can control.
• In Berrien RESA’s case, the schools get their Internet access through us. So we set QoS on their router and on our router. This guarantees the quality of the videoconference between the school and us. This was more essential in the early days of our videoconferencing when the districts had T1s to us. Now most of them are on fiber.

Packet Shaping

• Another way to guarantee the traffic for the videoconference is by using packet shaping.
• In Berrien RESA’s case, this is done by using Packeteer to guarantee up to 6 Meg of traffic from our network out to the world for the IP addresses of our videoconference systems and MCU. This means that if our bandwidth out is maxed out; our videoconferences will still be high quality. So far, even on super busy days of 20-30 VCs, we haven’t used more than that 6 Meg.

References

• Wikipedia on Virtual LANs
• Wikipedia on Quality of Service
• Wikipedia on Packet / Traffic Shaping

Your Turn

• How is the health of your network bandwidth?
• What methods do you use, prefer or recommend for bandwidth management?

Team-written by Janine Lim, Shane Howard, and Roxanne Glaser. The opinions expressed in these posts are based on our collective video conference experience connecting classes across multiple networks to connect them to zoos, museums, experts and other classes during the past 10 years. This series of posts reflects our usage and understanding, not that of any vendor or manufacturer. No one is paying us to write these. We are just sharing what we have learned.