Vodavi ip-7008d 사용자 가이드

다운로드
페이지 120
Glossary  
116
 
 
 
 
 
 
 
December, 2005  
 
Vodavi Telenium
IP
 
Product Guide 
 
mobility ▪ presence ▪ collaboration ▪ convergence 
 
 
Token Ring 
In a Token Ring network, the presence of a token (which is simply a particular bit setting) in a 
continually circulating transmission stream allows a device to change the bit setting (thus taking 
the token) and put a message in its place. The receiver of the message elsewhere in the token 
ring network removes the message and resets the bit setting (thus putting the token back) so 
that someone else in the ring of devices will be able to have a turn at using that message space. 
Topology 
A description of the physical layout of a network. 
Transponder 
A wireless communications, monitoring, or control device that picks up and automatically 
responds to an incoming signal. May be either passive or active. 
Tunneling 
Tunneling, also known as port forwarding, is the transmission of data intended for use only 
within a private, usually corporate network through a public network in such a way that the 
routing nodes in the public network are unaware that the transmission is part of a private 
network. Tunneling allows the use of the Internet, which is a public network, to convey data on 
behalf of a private network. 
UDP 
User Datagram Protocol.  User Data Protocol is part of the TCP/IP protocol suite.  It was created 
to provide a way for applications to access the connectionless features of IP.  UDP provides for 
exchange of datagrams without acknowledgements or guaranteed delivery.  This protocol is 
normally bundled with IP-layer software.  UDP is a transport layer (layer 4 of the OSI model), 
connectionless mode protocol, providing a (potentially unreliable, unsequenced, and/or 
duplicated) datagram mode of communication for delivery of packets to a remote or local user. 
Ultra Wide 
Band (UWB) 
ultra wideband (UWB): (see also: digital pulse wireless) is a wireless technology for transmitting 
large amounts of digital data over a wide spectrum of frequency bands with very low power for a 
short distance. Ultra wideband broadcasts very precisely timed digital pulses on a carrier signal 
across a very wide spectrum (number of frequency channels) at the same time. UWB can carry a 
huge amount of data over a distance up to 230 feet at very low power (less than 0.5 milliwatts), 
and has the ability to carry signals through doors and other obstacles that tend to reflect signals 
at more limited bandwidths and a higher power. 
Unicast 
In contrast to a broadcast, unicast datagrams are directed at a particular device on the network. 
Utilization 
A measurement of the amount of bandwidth used. Stated in terms of percentage of the total 
available. 
Vocoder 
A codec. See definition above. 
VoIP 
Voice over Internet Protocol.  The technology used to transmit voice conversations over a data 
network using the Internet Protocol.  Such data network may be the Internet or an Intranet 
(LAN).  There are several potential benefits to moving voice over a network using Internet 
Protocol including cost savings, one managed network, easier moving of phones in an office, and 
new, integrated services including unified messaging, Web integration for multi-media 
communications, etc. 
VOIP Gateway 
A VoIP trunk gateway is an interface that facilitates the use of plain old telephone service (POTS) 
equipment, such as conventional phone sets and fax machines, with a voice over IP (VoIP) 
network. 
VoWLAN 
VoWLAN (Voice over WLAN, sometimes called wireless VoIP, Wi-Fi VoIP): a method of routing 
telephone calls for mobile users over the Internet using the technology specified in IEEE 802.11b. 
Routing mobile calls over the Internet makes them free, or at least much less expensive than 
they would be otherwise. 
VPN 
Virtual Private Network: A connection over a public network like the Internet which is encrypted 
at both ends to provide exclusive and more secure access. 
WAN 
Wide-Area Network.  A computer network that spans a relatively large geographical area. 
Typically, a WAN consists of two or more local-area networks (LANs).  
WAP(1) 
Wireless Access Point.  See Access Point