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TELNET
TELNET is an acronym for TELetype NETwork. It is a terminal emulation
protocol that uses the Transmission Control Protocol (TCP). It provides a
virtual connection between TELNET server and TELNET client.
TELNET lets the client control the server and communicate with other servers
on the network. To start a Telnet session, the client user must log in to a
server by entering a valid username and password. Then, the client can enter
commands through the Telnet program, just as if they were entering
commands directly on the server console.
TFTP:
TFTP is an acronym for Trivial File Transfer Protocol. It is transfer protocol that
uses the User Datagram Protocol (UDP). It provides file writing and reading. It
does not provide directory service and security features.
U
UDP:
UDP is an acronym for User Datagram Protocol. It is a communications
protocol that uses the Internet Protocol (IP) to exchange the messages
between computers.
UDP is an alternative to the Transmission Control Protocol (TCP), that uses the
Internet Protocol (IP). Unlike TCP, UDP does not provide the service of dividing
a message into packet datagrams. UDP doesn't provide reassembling and
sequencing of the packets. This means that the application program that uses
UDP must make sure that the entire message has arrived and is in the right
order. Network applications that want to save processing time because they
have very small data units to exchange may prefer UDP to TCP.
UDP provides two services not provided by the IP layer. It provides port
numbers to help distinguish different user requests and as an option, a
checksum capability to verify that the data arrived intact.
Common network applications that use UDP include the Domain Name
System (DNS), streaming media applications (such as IPTV), Voice over IP
(VoIP), and Trivial File Transfer Protocol (TFTP).
User Priority:
User Priority is a 3
-
bit field that stores the priority level for the 802.1Q
frame. It is also known as PCP.
V
VLAN
: Virtual LAN is a method to restrict communication between switch ports.
VLANs can be used for the following applications:
VLAN unaware switching
: This is the default configuration. All ports are VLAN
unaware with Port VLAN ID 1 and members of VLAN 1. This means that MAC
addresses are learned in VLAN 1, and the switch does not remove or insert
VLAN tags.
