NECC - Videoconferencing over IP - Basic Hardware and Technology Issues

Robin Woodstone, Illinois Century Network

rwoodsome@illinois.net



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Hardware and Technology Issues with Video over IP

Vocabulary
- Gateways - technology bridge
- connects various types of protocols so they can interact together
- MCU - meeting place
- if you build the system and have the mcu, there is no charge
- can go through other companies
- price is about $50,000
- Gatekeepers
- hardware
- not necessary for IP to IP
- Codecs
- these do the decoding and encoding
- these are part of the camera usually
- Software Systems for Videoconferencing
- allows for more computer tools
- Whiteboard, remote desktop, chat
- Quality is not as high because of the applications
- Lots of variety of commercial meeting points available
- SIP (Session Initiated Protocol
- MPEG4 and more

IP Issues
- Cannot do multiple videos unless you have MCU
- you can purchase a switch that allows you to have multiple cameras and then just switch back and forth

Network Considerations
- Hubs - video and audio packets can't wait
- Network speeds at least 10/100 network
- Switches - consider congestion - how are they being used
- Routers - quality of service, memory, processing speed and congestion
- If you have a bandwidth problem, quality of service is poor, minimum bandwidth should be at least 512K for only video
- Bandwidth monitoring tools

Firewalls
- Source of greatest configuration problems because they do their job
- Private IP address - Static Public to Private
- Newer firewalls include video and audio packet service
- Firewall transversal systems (Ridgeway as an examle)

Troubleshooting
- Keep cell phone numbers handy
- Call test number to make sure it is not you
- Isolate the problem
- On network or off network
- Use common network tools - ping, trace route, bandwidth monitors
- Packet loss and jitter
- Always have plan B, C, D, etc. - Redundancy is important
- Include in extra time
- Use technology troubles to teach students and others critical thinking skills and technology skills by modeling and explaining details.

Ideas for Haddon Township School District
- Camnet has a gateway
- We have IP conferencing - that is just fine now.
- Colleges have MCUs, gateways, and gatekeepers - we might be able to use these during the day if we make a connection.
- We need to get network monitoring software
- MRTG - bandwidth monitoring -
- Ethereal - network analyzer
- Iperf - Network analyzer -