OPTICODEC-PC INTRODUCTION
1-15
Networking
Opticodec-PC supports both unicast and multicast streams. Each method has its own
advantages and your streaming application will determine which one to use.
To connect to the Internet using unicast, a server is required. This receives the out-
put of the encoder and creates the streams to which your listeners connect. Optico-
dec-PC supplies an output compatible with the free Darwin Streaming Server, which
is available for multiple platforms including Linux®, FreeBSD®, Sun Solaris®, Micro-
soft Windows®, and QuickTime Streaming Server for Apple Macintosh®. It is also
compatible with the SHOUTcast DNAS and the Icecast2 servers, also freely
downloadable.
Network Bandwidth Considerations
If you have access to large bandwidth Internet connectivity, you could conceivably
run the server software on your encoder computer—just connect the computer to
an Ethernet Internet feed and you are ready to go. However, most netcasters do not
have that option because the studio or program origination is in one place and the
Internet service provider (ISP) is somewhere else. If that’s the case, the best and most
economical way to connect is to establish what’s called a “co-lo,” or co-location,
which requires running your own server software on another computer, locating
that computer at the ISP, and running one stream per program from your encoder
to the server. Typically, this requires a full-time, non-dial-up dedicated connection
from your encoder to your ISP. Bandwidth requirements for this connection depend
upon the bitrate and number of streams being sent to the server.
A high reliability connection is also recommended to prevent encoder-server discon-
nects, although Opticodec-PC has the ability to automatically reconnect when this
occurs. If reliability is the goal, avoid consumer Internet connections, especially cable
Internet and some DSL. The relatively small upload bandwidth available from con-
sumer Internet services will severely limit the encoder and/or server. The reliability of
these services is generally not good enough for continuous streaming. Furthermore,
running a server on this type of Internet service may break your Internet service
agreement.
Many ISPs provide servers and administration services to run the appropriate stream-
ing server software. Although you are not responsible for the server administration
in this scenario, it comes at a price.
We have just described how to get your program on the network. Here is where the
listeners come in. There are different ways that people can connect to your stream.
•
Most Internet streams are implemented via
unicasting,
which requires a sin-
gle, independent connection to the server for each stream. (See Unicast on
page 1-24.)
•
In a
multicast
, a single stream is shared among the player clients. Although
this technique reduces network congestion, it requires a network that either
has access to the multicast backbone (otherwise called the Mbone) for content
generally distributed over the Internet, or is multicast-enabled for content dis-
tributed within a contained private network. Multicast streams are sent di-
rectly to a group address, such an IP multicast address, which many client com-
