Networks can be divided into two categories i.e., those using point-to-point connections and those using broadcast channels. Broadcast channels are sometimes referred to as multi-access channels or random access channels. The protocols used to determine who goes next on a multi-access channel belong to a sublayer of the data link layer called the MAC (Medium Access Control) sublayer. The MAC sublayer is especially important in LANs, nearly all of which use a multi-access channel to communicate. WAN, in contrast, uses point-to-point links except for satellite networks.
Internet
Methods of Data Transmission
For data transmission various methods are used:-
- Synchronous Transmission
- Asynchronous Transmission
Synchronous Transmission
This method of data transmission involves block of characters that are transmitted at regular time sequences. Each of the block of characters is marked with synchronization characters. The receiving end, accepts the data block, till it detects the ending character or after a predefined number of characters are received, indicating end of a message.
Congestion in Network
Data is transferred from the source to the destination in a network. Sometimes the data is transferred in bulk in the network which affects the traffic. Now, if the traffic gets more and more in the network, therefore increasing the congestion. This leads to delay in data receiving or sending packet loss, and blocking of the connection resulting in the capacity of the network.
Network Congestion:- Network protocols are there which help in reducing the network traffic, by taking the SHORTEST PATH ALGORITHM which says that, the data is routed by seeing the shortest path of the desired destination.