Card Set Information
half duplex connection
transmits data in both directions, but in only one direction at a time
full duplex connection
transmits data in both directions and at the same time
DTE (Data Terminal Equipment)
the device, such as a workstation or a terminal, that connects to a DCE.
DCE (Data Communications Equiment)
the device, such as a modem, that terminates a data transmission line (circuit terminating device)
a high-speed connection to which multiple devices can attach
2 Data Connections that Firewire supports
Is Firewire hot pluggable?
SCSI (Small Computer System Interface)
specially designed interface that allows for a very high speed transfer of data between the disk drive and the computer (disk drives, tape drives, CDs, DVDs, [more permanent nature])
How many devices can you connect to one SCSI adapter?
serial connection or bus that can carry multiple channels of data at the same time; network of high-speed links and switches
How many devices can an InfiniBand handle?
How many devices can Fibre channel support?
Where are start bits added?
start bits added to signal the beginning of the frame (0)
Where are stop bits added?
stop bits added to the signal at the end of a frame (1)
the unit of transmission is a sequence of characters ; technique for maintaining synchronization between a receiver and the incoming data stream
What is a point-to-point connection?
direction connection between a terminal and a mainframe computer; single wire runs between the two devices and no other terminals or computers share this connection
Does a point-to-point connection require polling?
de facto standard
a standard that has not been approved by a standards-making organization but has become a standard through wides-spread use
Is asynchronous connection most complex example of a data link protocol?
Is a start bit always 1?
start and end sequences typically 8 bits in length
Real time application examples
streaming voice, video, music
A medium can be divided in what 3 ways?
FDM (Frequency division multiplexing)
one of the simplest, assignemnt of nonoverlapping frequency ranges to each "user" of a medium
How does FDM work?
a channel is assigned to each user, and a tuner separates one channel from the next and presents each as an individual data stream to you, the viewer
What does FDM assign each user?
a separate channel
What is a demultiplexor?
a multiplexor that un-multiplexes the data stream and delivers the individual streams to the appropriate devices
Which two multiplexing techniques use guard bands and therefore waste unused transmission space?
2 types of TDM
STDM (Synchronous time division multiplexing), STDM (statistical time division mulitplexing)
How does Synchronous TDM work?
accepts input from a fixed number of devices and transmits their data in an unending
When was T-1 service created? What was its original purpose?
1960's to provide a high-speed connection between AT&T's switching centers
Who developed SONET in the US?
Which multiplexing technique supports SONET?
How does WDM work?
involves fiber-optic systems and the transfer of multiple streams of data over a single
fiber using multiple, colored laser transmitters
What medium does WDM multiplex on?
single fiber-optic line
Does WDM support multiple concurrent signals?
When is statistical TDM a good choice?
when trying to save space
What is TDMs other name?
At what layer of TCP/IP is multiplexing done?
Does FDM use guardbands?
How many users does TDM allow to transmit at a time?
How many channels does TDM send over one line?
What is DSL?
Discrete multitone is found in what systems?
Code division multiplexing is based on what?
Is noise a problem with both analog and digital signals?
White noise also called what?
How can white noise be prvented for both analog and digital signals?
Is white noise dependent on the temperature of the medium?
Impulse noise is known as what?
What is impulse noise?
What causes crosstalk?
Is crosstalk a problem with fiber optic cable?
How can crosstalk be prevented?
Why are echo suppressors used?
What causes jitter?
What is jitter?
At what OSI layers is error detection done?
Parity checks are used with what types of connections?
Cyclic checksum is also known as what?
LRC is also known as what?
CRC treats each data packet as what?
Is CRC foolproof?
What is frame relay used for?
Which medium is least prone to generating errors?
What is the most common form of error control?
Which protocol is stop-and-wait technique used with?
What is sliding window?
What is sliding windows function?
Window size of 7 would allow how many data packets at a time?
What is forward error correction?
Is attenuation a form of error?
What is ACK?