Networking Flashcards
Point to Point channels
If two computers are directly connected, they can communicated with each other directly.
If two computers that do not share a link, they can communicate indirectly to each other through other computers.
Some possible topologies for point to point communication include: Star, fully connected, irregular and hierarchical connections.
Broadcast topology
A broadcast channel is a single communication channel shared by all the communicating computers.
Any message sent by one computer is received by all the other computers.
The message must contains the address of the intended receiver so that all the other computers must ignore it.
Some possible topologies for broadcast communication include: Bus and the ring connections
Parity checking
Prior to transmission an additional bit is appended to a character such that
The sum of 1s in the character is an odd number (odd parity)
The sum of The sum of 1s in the character is an even number (even parity)
if odd make numbers of 1[’s odd and vice verser
Message Switching
Message switching is a technique that overcomes the problems of circuit switching
For irregular network topology, the message is passed from node to node until it reaches its destination
Packet Switching Network
There are two types of services
- Virtual Circuit
- Datagram
Non return to zeros (NRZ)
Encoding the bits using two voltage levels. A high one and a low one. This can be used to represents one and zero.
Known as NRZ
For synchronous network, this would be inadequate because the receiving station might misinterpret the bit pattern
Manchester Encoding
It is easier for the receiving hardware to detect a change in voltage rather than a value.
The rising and the falling edges of the signal are used to encode the ones and the zeros
Binary one is represented by a high to low transition in the signal
Binary zero is represented by a low to high transition in the signal
