Networks Models Flashcards
Name the 5 Layers of TCP/IP protocol (ordered)
- Physical Layer
- Data Link Layer
- Network Layer
- Transport Layer
- Application Layer
What is the communication type for the top 3 layers (application, transport, and network) and what does it mean?
The top 3 layers are considered end-to-end meaning that the data unit exchanged should not be changed by any router or link-layer switch.
What is the communication type for the bottom 2 layers (Physical and Data Link) and what does it mean?
The bottom 2 layers are considered hop-to-hop meaning that the packet created by the host is changed only by routers (NOT Link-Layer switches), and passed from one hop to another (hop meaning one host or router)
Describe the Physical Layer and name its unit of travel.
The physical layer connects through a transmission medium that carries electrical or optical signals.
The physical layer carries individual bits in a frame across the link.
The unit of travel are bits.
Describe the Data-Link Layer and name its unit of travel
The data link layer is responsible for moving a packet through the link.
A router chooses the best link, but the data-link layer actually moves the datagram across the link.
Unit of travel is a Frame.
Describe the Network Layer and its unit of travel
The Network Layer is responsible for creating a connection between the source computer and the host computer and it is also responsible of making a route between host and destination.
The main unit of travel is Datagram
Describe the Transport Layer and its main unit of travel
The transport layer gets the message from the application layer then encapsulates it into a transport layer packet and sends it through a logical (imaginary) connection to the transport layer at the destination host.
The unit of travel would be a segment or user datagram.
Describe the application layer and its unit of travel.
The application layer’s communication is process-to-process with an exchange of messages making its unit of travel
In what trend does encapsulation occur in the TCP/IP suite?
Encapsulation occurs downward (Application layer message is encapsulated in a transport-layer segment (or user datagram). Whereas decapsulation occur upward.
