As shown in Figure 3.1, transport-layer protocols are implemented in the end
systems but not in network routers. On the sending side, the transport layer converts
the application-layer messages it receives from a sending application process into
transport-layer packets, known as transport-layer segments in Internet terminology.
This is done by (possibly) breaking the application messages into smaller chunks and
adding a transport-layer header to each chunk to create the transport-layer segment.
The transport layer then passes the segment to the network layer at the sending end
system, where the segment is encapsulated within a network-layer packet (a datagram) and sent to the destination. It’s important to note that network routers act only
on the network-layer fields of the datagram; that is, they do not examine the fields of
the transport-layer segment encapsulated with the datagram. On the receiving side,
the network layer extracts the transport-layer segment from the datagram and passes
the segment up to the transport layer. The transport layer then processes the received
segment, making the data in the segment available to the receiving application.
As shown in Figure 3.1, transport-layer protocols are implemented in the endsystems but not in network routers. On the sending side, the transport layer convertsthe application-layer messages it receives from a sending application process intotransport-layer packets, known as transport-layer segments in Internet terminology.This is done by (possibly) breaking the application messages into smaller chunks andadding a transport-layer header to each chunk to create the transport-layer segment.The transport layer then passes the segment to the network layer at the sending endsystem, where the segment is encapsulated within a network-layer packet (a datagram) and sent to the destination. It’s important to note that network routers act onlyon the network-layer fields of the datagram; that is, they do not examine the fields ofthe transport-layer segment encapsulated with the datagram. On the receiving side,the network layer extracts the transport-layer segment from the datagram and passesthe segment up to the transport layer. The transport layer then processes the receivedsegment, making the data in the segment available to the receiving application.
การแปล กรุณารอสักครู่..