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GLOSSARY ORBAN
MODEL
1010
multicast
An efficient, one-to-many form of streaming. Users can join or leave a
multicast but cannot otherwise interact with it.
multihomed
A server with multiple IP addresses.
NAT (Network Address Translation)
A technique sometimes used so that multi-
ple computers can share a single IP address.
netcast
A broadcast of live video or audio on a network or the Internet.
NIC (network interface card)
NNTP
NTU (network termination unit)
ODFM (Orthogonal Frequency-Division Multiplexing)
open source
A term for the cooperative development of software by the Internet
community. The basic principle is to involve as many people as possible in writing
and debugging code by publishing the source code and encouraging the formation
of a large community of developers who will submit modifications and enhance-
ments.
packet
A unit of data information consisting of header, information, error detec-
tion, and trailer records. QTSS/DSS uses TCP, UDP, and IP packets to communicate
with streaming clients.
payload
PDC
PDU (Protocol Data Unit)
Information that is delivered as a unit among peer enti-
ties of a network and that may contain control information, address information, or
data. In layered systems, a unit of data that is specified in a protocol of a given layer
and that consists of protocol-control information of the given layer and possibly user
data of that layer.
PHS
pixel
A single dot in a graphic image with a given color and brightness value.
playlist
A set of media files in the QTSS or DSS media folder specified to play one
after the other or in random sequence.
POP3 (Post Office Protocol)
port
A sort of virtual mail slot. A server uses port numbers to determine which ap-
plication should receive data packets. Firewalls use port numbers to determine
whether data packets are allowed to traverse a local network. “Port” usually refers
to either a TCP or UDP port.
PPPoE (Point-to-Point Protocol over Ethernet)
PPTP (Point-to-Point Tunneling Protocol)
A protocol for a Virtual Private Net-
work (VPN) developed by a consortium including Microsoft and is used for establish-
ing VPN (Virtual Private Network) tunnels across the Internet. This allows remote
users to securely and inexpensively access their corporate network from anywhere
on the Internet. PPTP uses a client-server model for establishing VPN connections.
Most Microsoft operating systems ship with a PPTP client, so there is no need to pur-
