Ccna

Front 1

Same-layer interaction on different computers

Back 1

Each layer of a networking model works with the same layer on another computer. The protocol defined by each layer uses a header that is transmitted between the computers to communicate what each computer wants to do.

Front 2

Adjacent-layer interaction on the same computer

Back 2

A higher layer might need a particular service that is not included in that layer. To perform the missing function, the protocol at the higher layer requests that the next lower layer perform the needed function.

Front 3

TCP/IP Data Encapsulation

Back 3

1. Create the application data and headers
2.Package the data for transport— Transport layer (TCP or UDP) creates the transport header and places the data behind it.
3. Add the destination and source network layer addresses to the data— The network layer creates the network header, which includes the network layer addresses, and places the data behind it.
4.Add the destination and source data link layer addresses to the data— The data link layer creates the data link header, places the data behind it, and places the data link trailer at the end.
5.Transmit the bits— The physical layer encodes a signal onto the medium to transmit the frame.

Front 4

7 Layers of the OSI Model

Back 4

1. Physical
2. Datalink
3. Network
4. Transport
5. Session
6. Presentation
7. Application

Front 5

Application (Layer 7)

Back 5

Interface between network and application software.

Front 6

Presentation (Layer 6)

Back 6

How data is presented.

Special processing, such as encryption.

Front 7

Session (Layer 5)

Back 7

Establishing and maintaining end-to-end bidirectional flows between endpoints. Includes managing transaction flows.

Front 8

Transport (Layer 4)

Back 8

Reliable or unreliable delivery.

Multiplexing.

Front 9

Network (Layer 3)

Back 9

Logical addressing, which routers use for path determination.

Front 10

Data link (Layer 2)

Back 10

bits into bytes, and bytes into frames.
Access to the media using MAC address.
Error detection/recovery.

Front 11

Physical (Layer 1)

Back 11

Moving of bits between devices.

Specification of voltage, wire speed, and cable pinouts.

Front 12

Name three benefits to layering networking protocol specifications.

Back 12

reduced complexity, standardized interfaces, modular engineering, interoperable technology

Front 13

What header or trailer does a router discard as a side effect of routing?

Back 13

the data-link header and trailer as a side effect of routing. This is because the network layer, where routing is defined, is interested in delivering the network layer (Layer 3) PDU from end to end. Routing uses intermediate data links (Layer 2) to transport the data to the next routers and eventually to the true destination. The data-link header and trailer are useful only to deliver the data to the next router or host, so the header and trailer are discarded by each router.

Front 14

What terms are used to describe the contents of the data encapsulated by the data link, network, and transport layers, respectively?

Back 14

Answer: Frame, packet, and segment, respectively.

Front 15

TCP/IP

OSI

Back 15

Transmission Control Protocol and Internet Protocol

Open Systems Interconnection