They are 3 type of Modes
1.Simple mode :- Data transfer only Single Directions Between Segments
Simplex allows for communication in one direction only and doesn't allow switching directions. This is sometimes specified programmatic ally as Simplex Server or Simplex Client.
2.Half Duplex :- Data transfer Both Directions But not same time one device active, wait and receive
Half-Duplex allows for communication in one direction at one time then can switch to the opposite direction. An example is the POP3 Protocol (as well as FTP, NNTP, SMTP).
3.Full Duplex:- Data trancesfer both directions at the same time between communicate segments
1.Simple mode :- Data transfer only Single Directions Between Segments
Simplex allows for communication in one direction only and doesn't allow switching directions. This is sometimes specified programmatic ally as Simplex Server or Simplex Client.
2.Half Duplex :- Data transfer Both Directions But not same time one device active, wait and receive
Half-Duplex allows for communication in one direction at one time then can switch to the opposite direction. An example is the POP3 Protocol (as well as FTP, NNTP, SMTP).
3.Full Duplex:- Data trancesfer both directions at the same time between communicate segments
Full-Duplex allows for communication in either direction at any time. An example is HTTP Pipelining.
Types of Messages
We actually have three different methods of sending messages over computer networks. Those methods are unicast, multicast and broadcast.
Unicast Message
When using unicast method, one device will send the message to exactly one destination device. If some device needs to send a message to multiple devices, it will have to send multiple unicast messages, each message addressed to a specific device. So, the sender has to send a separate message to each destination device, and to do that it has to know the exact IP address of each destination device. Remember that in unicasting, each packet is destined for only one device.
In our example we have one source device, and multiple destination devices which belong to different groups of devices (marked with color). As we can see on the picture, unicast messages will be sent to specific devices by using the specific IP address of the device, as the destination address in the packet.
Unicast Message
Broadcast Message
The second method of sending messages is called the broadcasting. Broadcast is a packet that's sent to all devices on specific network. The destination address in the packet is the special broadcast address. If the packet has a broadcast address, all devices that receive that message will process it. So, all devices on the same network segment will see the same message. Another thing to remember is that routers don't forward broadcast messages. The router will receive the broadcast traffic, but it will not forward it through the router.
Broadcast Message
Multicast Message
Multicasting identifies logical groups of computers. A single message can then be sent to the group.
Multicast Message
Multicasting uses the Internet Group Management Protocol (IGMP) to identify groups and group members.
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