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Flashcards in OSI Model Deck (12)
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Segments of data are arriving at their destination with errors. Which layer of the OSI Model is responsible for the reliable delivery of segments without error?

Layer 4 - Transport Layer. It is also responsible for the delivery of segments.


What OSI Layer does TCP and UDP operate at?

Layer 4 - Transport Layer


PDU's are data at different layers of the OSI Model. What are the PDU's and at what Layer do they reside?

Segment is at Layer 4, Packet is at Layer 3, Frame is at Layer 2, and Bits is at Layer 1. Some People Fear Birthdays.


Layer 1 (Physical) is concerned with what?

The transmission of bits on a network.


Layer 2 (Data Link) is concerned with what?

The packaging of data into frames and transmitting those frames on the network, performing error detection and error correction, uniquely identifying network devices with an address and handling flow control.


Layer 3 (Physical) is concerned with what?

Forwarding data based on logical addresses.


Layer 4 (Transport layer) is concerned with what?

Acts as a dividing line between the upper layers and the lower layers. Specifically, messages are taken from the upper layers (Layers 5–7) and encapsulated into segments for transmission to the lower layers (Layers 1–3). This is known as Segmentation. Similarly, data streams coming from lower layers are decapsulated and sent to Layer 5 (the session layer) or some other upper layer, depending on the protocol.


Layer 5 (Session Layer) is concerned with what?

It's responsible for setting up, maintaining, and tearing down sessions.


Layer 5 (Presentation Layer) is concerned with what?

Responsible for the formatting of data being exchanged and securing the data with encryption


Layer 7 (Application Layer) is concerned with what?

Provides application services to a network. Supports services used by end-user applications, and for advertising available services. User applications do not reside here.


What layer of the OSI Model do Hubs and Repeaters operate at?

Layer 1


What layer of the OSI Model do Switches and Bridges operate at?

Layer 2