MicroNet Technology SP3367A - Manual (Page 68)

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bridge itself; the bridge is thus transparent to the communicating
workstations. It involves frame forwarding, learning workstation addresses
and ensuring no topology loops exist (in conjunction with the
Spanning-Tree algorithm).
UDP
User Datagram Protocol - A connectionless transport protocol that runs on
top of TCP/IP's IP. UDP, like TCP, uses IP for delivery; however, unlike TCP,
UDP provides for exchange of datagrams without acknowledgments or
guaranteed delivery. Best suited for small, independent requests, such as
requesting a MIB value from an SNMP agent, in which first setting up a
connection would take more time than sending the data.
UNI signaling
User Network Interface signaling for ATM communications.
Virtual Connection (VC)
A link that seems and behaves like a dedicated point-to-point line or a
system that delivers packets in sequence, as happens on an actual
point-to-point network. In reality, the data is delivered across a network via
the most appropriate route. The sending and receiving devices do not have
to be aware of the options and the route is chosen only when a message is
sent. There is no pre-arrangement, so each virtual connection exists only
for the duration of that one transmission.
WAN
Wide area network - A data communications network that spans any
distance and is usually provided by a public carrier (such as a telephone
company or service provider).