Computer network "point-to" and "end-to-end"

1. Dot to point

The point is the data link layer, because the data link layer is responsible for directly connected to the communication between the two nodes, a node of the data link layer to accept the network layer of data and encapsulation, the data frame from the link to the next node adjacent to it.
end-to-end is the transport layer, because both TCP and UDP protocol, it is responsible for the upper-level delivery of data from the sender to the receiving end, regardless of how many nodes across. Only TCP is more reliable and UDP is unreliable. So called end-to-end, that is, from the sending side to the receiving end.

2.

Essentially, a communication subnet consisting of a physical layer, a data link layer, and a network layer provides a point-and-place service to a host in a network environment, while the transport layer provides end-to-end communication for hosts in the network.
the communication of a directly connected node peer entity is called point-to-point communication. It only provides communication between one machine to another machine and does not involve the concept of a program or process. At the same time, the point-to communication does not guarantee the reliability of the data transmission, nor does it indicate which two processes are communicating between the source host and the destination host, all of which are carried out by the transport layer.

3. End-to-end

 end-to-end communication is based on point-to-point communication, which is made up of a segment of point-to-point communication channel, which is a higher level of communication than point to place communication, to complete the communication between applications (processes). End-to-end vs. point to Dot is for the relationship between the devices that are transmitted across the network.
End-to-end transmission refers to the data before transmission, through a variety of switching equipment, at both ends of the device asked to establish a link, as if they are directly connected, the link is established, the sender can send data, until the data is sent, the receiving side to confirm the successful reception.
Point-to system refers to the sending end of the data to the device directly connected to it, the device at the appropriate time and the data to the directly connected to the next device, through the directly connected devices, the data to the receiving end. The advantage of end-to-end transmission is that after the link is established, the transmitting side knows that the receiving device must be received, and the intermediate switching device does not need to store and forward, so the transmission delay is small; the disadvantage is that the transmitting device is always involved in the transmission until the receiving end receives the data. If the delay of the whole transmission is very long, then it is very wasteful to the transmitting side of the device.
Another disadvantage of end-to-end transmission is that if the receiving device shuts down or fails, the end-to-end transmission cannot be achieved. The advantage of point-to-point transmission is that the sending device sends out the data, its task is completed, it does not need to participate in the whole transmission process, so it does not waste the resources of the sending end device. In addition, even if the receiving end device shuts down or fails, the point-to transfer can also be buffered using the storage and forwarding technology.
The disadvantage of point-to-point transmission is that after the sender sends out data, it does not know whether the receiving end can receive or receive data. In different tiers of a network system, end-to-end transmission may be used, or point-to-point transmission may be used.
such as the Internet, the network interconnection layer and the following layers of the use of dot-to-point transmission, Transport layer and above using end-to-end transmission.