There are many network factors that can contribute to an online meeting experience. This TechNote describes bandwidth requirements for a good online meeting experience.
All meeting rooms can optimize the room bandwidth, to get the best experience. Choose Meeting > Room Performance And Appearance (Connect 7.x) or Meeting > Preferences > Room Bandwidth (Connect 8.x) within each individual room. Setting this option to DSL provides a good experience for users on LAN and broadband connections. If most of the users are using a modem connection, setting to Modem is a better option.
Select LAN only if all the users are on a high-speed network and presenters are using high end systems (2Ghz and above desktops). The LAN results in applications sending high-quality audio, video, and screen-shared images.
Note: This setting not only increases bandwidth consumption but also increases CPU usage on the presenter's system. If CPU usage goes beyond 80%, latency increases, resulting in choppy audio and video.
Individual users can also optimize bandwidth use:
- In Connect 7, by default the connection speed for each presenter or participant is set to LAN. It is good practice to set the connection speed to the actual connection speed of the user. Choose Meeting > Manage My Settings > My Connection Speed. If participants experience latency or choppy audio, ask them to lower their individual meeting room setting.
- In Connect 8, if participants experience latency or choppy audio, ask them to lower their individual meeting room settings under Meeting > Preferences > Video.
If multiple users are sharing a T1 or DSL connection, make sure that they're aware that this connection is a shared resource. Be sure to divide the total bandwidth by the number of users sharing the connection.
- T1 - 1.5 Mbits/sec up and down.
- DSL varies based on type but in general 350 up and 1 MB down
Below are some bandwidth calculations based on a meeting with audio, video, and slides. Calculations also based on 1024x768 full screen.
- 1 presenter can generate about 26 Kbits/sec of data. Viewers require about 29 Kbits/sec of down stream bandwidth to have a good experience.
- Having more than one presenter on a modem room setting is not recommended.
- If screen sharing is added to Modem, total bandwidth required is about 49 Kbits/sec. This setting is close to saturating a modem connection. Any bottleneck in the network can cause latency or dropped message. (Not recommended.)
- 1 presenter generates close to 125 Kbits/sec. Each viewer requires about 128 Kbits/sec to consume all the data generated.
- Adding screen sharing: 184 Kbits/sec
- To have a good live experience with DSL setting, make sure that viewers have at least 200 Kbits/sec down stream bandwidth. And, make sure that presenters have a 200 Kbits/sec upstream bandwidth.
- 1 presenter generates close to 250 Kbits/sec. Each viewer requires about 255 Kbits/sec to consume all the data generated.
- Adding screen sharing results in about 300 Kbits/sec
- To have a good live experience with LAN setting, make sure that viewers have at least 400 Kbits/sec down stream bandwidth. And, make sure that presenters have a 400 Kbits/sec upstream bandwidth.
Note: Screen sharing bandwidth can vary based on the content being shared and resolution of the screen. Also, these numbers are a general guideline and actual capacity varies with each network environment.
For more details on specific system requirements, see the System Requirements page.