Multipoint Control Units(MCUs)

Gabe MoultonThe Ohio State UniversityMoulton.13@osu.edu

Internet2 Commons Site Coordinator TrainingSeptember 27, 2004Austin, Texas

What Are they?

Scenario 1: Point to Point call• Each endpoints captures and sends one audio and one video

stream• Each endpoint receives and displays one audio and video stream

Scenario 2: Multiple end point call• Each endpoints captures and sends one audio and one video

stream• Now there are potentially multiple incoming audio and video

streams• Most endpoints don’t know what to do with this

In walks the MCU• It receives all video and audio streams• Mixing the audio and sends it back out as one stream to each

endpoint• Video is mixed and transmitted as one stream to each based on the

configuration of the conference

MCU Conference Request Considerations

Layouts• Continuous Presence (CP)

–Multiple sites visible on screen at once

• Voice Switched–One site on screen at a time–Switches based on who is talking

Data Rate Choices• Increasing the data rate doesn’t always increase the quality of the conference

–Bandwidth availability considerations

Multipoint Control Units: Hardware vs Software

Hardware• Dedicated, real-time operating system• RADVISION• Polycom• Tandberg

Software• Based on standard Operating systems (Windows, Linux)• First Virtual Communications

Embedded • Has dedicated hardware for processing• Works well for small numbers

MCU Control Functions

Defining a conference• Speed• Number of users• Multiple windows

Operating a conference• Dial out• Dial in

Monitoring a conference Monitoring an MCU Cascading MCUs

MCUs available in the market

RADVision H.323• 9 ports at 384Kbps• Small, simple, includes Gatekeeper

RADVision ViaIP• 50 ports at 384Kbps, expandable • Powerful, reliable; ECS Gatekeeper

Accord/Polycom MGC• 48 ports at 384Kbps, Expandable multi Format capable• Many advanced features; no Gatekeeper necessary

Tandberg• 16 ports at 384Kbps• Many advanced features

Codian• 20 up to 80 ports• Advanced features, no gatekeeper required

VCON• VCB-2000• Streaming Capabilities

RADVISION MCU-323

9 Users@384Kbps (5@768Kbps, 15@128Kbps) Built-in Web server. Provides operational control of

who is in a conference and who has the floor. Also controls application sharing and MCU Cascading.

Built-in Telnet server. Provides optional remote control and monitoring.

PC remote configuration software. Provides conference definitions, names, and software updates.

List price $22.5K. Discounts as low as $10K.

Tandberg MCU

16 users, 3 simultaneous conferences

Support for H.264

Embedded Encryption

Supports ISDN and IP

Embedded webserver for control and configuration

Small 1U form factor, 19” Rackmountable

Polycom MGC

3 Flavors, 25, 50 and 100

Capacity varies by configuration

Support for H.264

Can support ISDN, IP and ATM

Separate Software control

Priced by configuration

RADVISION via-IP

4 flavors 15, 30, 60, 100384Kbps capacity by type

• 15 12• 30 24• 60 42• 100 70

Support for SIPCan add gateway cardsChassis based system, expandableGatekeeper based dialing

Commons MCU Test Facility

Three MCUs are available for testing and discussion.

• Web interface• Telnet interface• PC interface

The Commons will support remote or onsite (you come to Ohio) testing.

Useful for assisting in evaluations for your own purchases.

Questions?

Gabe Moulton

Moulton.13@osu.edu