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The Ethernet switching hub only routes video packets that are addressed to the specific client
devices on the appropriate output ports. This keeps video traffic flowing smoothly to the desktops
that need it, and insulates the corporate backbone network from high bandwidth video.
This establishment of dedicated "subnets" prevents conflicts between video and other data, and
also prevents video from hogging shared network bandwidth. Switched Ethernet is often
recommended for high-quality video to the desktop as it can often use most of the existing
network infrastructure such as Network Interface Cards (NICs), hubs, and cabling.
Fast Ethernet:
Fast Ethernet generally refers to high speed Ethernet such as 100BaseT which supports 100Mbps
bandwidth—a tenfold increase over 10Mbps 10BaseT. Fast Ethernet works the same from a
protocol and access point of view as standard Ethernet, only faster. The higher bandwidth
provides better support for streaming video. Many enterprises install Fast Ethernet as an upgrade
or as a network backbone. The next generation of Fast Ethernet—Gigabit Ethernet—is in
development.
ATM:
Asynchronous Transfer Mode uses hardware switching to provide not only high speed—25Mbps
to 2.5Gbps—but it also a guaranteed Quality of Service (QoS) and multicasting through a circuit-
switched connection. It uses fixed 53 byte packets and was designed from the outset for
multimedia data transmission such as video, sound, and images. Physical media includes twisted
pair, coax, and fiber. Because of its speed and expense, it was originally used for wide-area long-
haul networks, but is now beginning to be deployed as a local area backbone.
Public Internet
The public Internet is moving at a breathtaking pace in terms of content, access, and subscribers.
There is a strong motivation to be able to deliver video content for a number of potential
applications including webcasting, product advertising and catalogs, interactive shopping, and
virtual travel.
Access
Access to the public Internet is generally done through an "access network" that connects to the
"core network" or backbone of the Internet.
Core
Network
Access
Network
Web
Server
Client
Internet Access to Video
Video
Server
HTTP
UDP
TCP
HTTP
(Tunnel)
Access Methods:
Modem, ISDN, ADSL,
Cable modem
New
Protocols:
RTP
RTSP
RSVP
IPv6