G−I - Cisco RJ-45-to-AUX Brochure

A Data Link layer switching protocol used across multiple virtual circuits of a common carrier, giving
the end user the appearance of a dedicated line.
frame tagging
A VLAN implementation method used to add VLAN information to data frames. As a frame enters
the switch, it is tagged with VLAN information. It retains this information through the switching
fabric; the tagging is removed before the frame exits the switch port with the attached destination
interface. The process is transparent to the sending and receiving interfaces.
Frame Type field
In a data frame, the field that names the protocol being sent in the frame.
Frequency Division Multiplexing (FDM)
A technology that divides the output channel into multiple, smaller−bandwidth channels, each using a
different frequency range.
full backup
A backup method in which every file on the hard drive is copied.
full duplex
A transmission method in which the sending and receiving (Rx and Tx) channels are separate;
therefore, collisions cannot occur. Data is transmitted in two directions simultaneously on separate
physical wires.
G−I
gateway
A hardware and software solution that enables communication between two dissimilar networking
systems or protocols. Gateways usually operate at the upper layers of the OSI protocol stack, above
the Transport layer.
gigabit (Gb)
One billion bits or one thousand megabits.
Gigabit Ethernet
IEEE specification for transfer rates up to one gigabit per second.
guaranteed flow control
A method of flow control in which the sending and receiving hosts agree upon a rate of data
transmission. After they agree on a rate, the communication will take place at the guaranteed rate until
the sender is finished. No buffering takes place at the receiver.
half duplex
A circuit designed for data transmission in both directions, but not simultaneously.
head−of−line blocking
A situation in which congestion on an outbound port limits throughput to uncongested ports. It is
completely different from oversubscription. Physical data from another source device blocks the data
of the sending device.
High−Speed Serial Interface (HSSI)
The network standard for high−speed serial communications over WAN links. It includes Frame
Relay, T1, T3, E1, and ISDN.
host
Any system on a network. In the Unix world, any device that is assigned an IP address is a host.
host ID
A unique identifier for a client or resource on a network.
hostname
The NetBIOS name of the computer or node, given to the first element of the Internet fully qualified
domain name (FQDN). It must be unique on your network.
Hot Standby Routing Protocol (HSRP)
A Cisco protocol that provides a redundant route processor on a segment. Should a route processor or
link to a route processor fail, another configured router in a Standby Group can take over the routing
responsibilities. The routers participating in an HSRP Standby Group are configured with a virtual
MAC address and a virtual IP address. A separate instance of HSRP can exist for each VLAN.
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