
52GLOSSARY
broadcast storm | Multiple simultaneous broadcasts that typically absorb all the available  | 
  | network bandwidth and can cause a network to fail. Broadcast storms  | 
  | can be due to faulty network devices.  | 
collision | A term used to describe two colliding packets in an Ethernet network.  | 
  | Collisions are a part of normal Ethernet operation, but a sudden  | 
  | prolonged increase in the number of collisions can indicate a problem  | 
  | with a device, particularly if it is not accompanied by a general increase  | 
  | in traffic.  | 
CSMA/CD | |
  | defined in Ethernet and IEEE 802.3 standards in which devices transmit  | 
  | only after finding a data channel clear for a period of time. When two  | 
  | devices transmit simultaneously, a collision occurs and the colliding  | 
  | devices delay their retransmittions for a random length of time.  | 
endstation | A computer, printer or server that is connected to a network.  | 
Ethernet | A LAN specification developed jointly by Xerox, Intel and Digital  | 
  | Equipment Corporation. Ethernet networks use CSMA/CD to transmit  | 
  | packets at a rate of 10Mbps over a variety of cables.  | 
Ethernet address  | See MAC address.  | 
Fast Ethernet | An Ethernet system that is designed to operate at 100Mbps.  | 
forwarding | The process of sending a packet toward its destination using a  | 
  | networking device.  | 
filtering | The process of screening a packet for certain characteristics, such as  | 
  | source address, destination address, or protocol. Filtering is used to  | 
  | determine whether traffic is to be forwarded, and can also prevent  | 
  | unauthorized access to a network or network devices.  | 
flow control | A congestion control mechanism. Congestion is caused by devices  | 
  | sending traffic to already overloaded port on a Switch. Flow control  | 
  | prevents packet loss and and inhibits devices from generating more  | 
  | traffic until the period of congestion ends.  | 
full duplex | A system that allows packets to be transmitted and received at the  | 
  | same time and, in effect, doubles the potential throughput of a link.  | 
half duplex | A system that allows packets to transmitted and received, but not at  | 
  | the same time. Contrast with full duplex.  |