CCNA Exploration Network Fundamentals Lecture 0 http goo

CCNA* Exploration: Network Fundamentals Lecture 0 - http: //goo. gl/y. UI 8 t. N Communicating over the Network *CCNA - Cisco Certified Network Associate

Useful links 1. http: //nsuacad. net/ 2. Packet tracer https: //www. netacad. com/group/offerings/pa cket-tracer

Communicating over the Messages

Components of the Network ● Devices End-devices(laptop, wifi-router, printer) используются end-user’ом ○ Intermediary devices(hub, switch) - промежуточные устройства ○ ● Media(среда передачи данных) ● Services(Software)

Intermediary devices 1. Regenerate & retransmit data signals 2. Maintain information about what pathways exist through the network and internetwork 3. Notify other devices of errors and communication failures 4. Permit or deny the flow of data, based on security settings

Internet - Internetwork

Network representation

Technology independent protocols

Protocol data units & Encapsulation PDU - единица информации на каждом уровне модели ● Data - The general term for the PDU used at the Application layer ● Segment - Transport Layer PDU ● Packet - Internetwork Layer PDU ● Frame - Network Access Layer PDU ● Bits - A PDU used when physically transmitting data over the medium

Comparing OSI & TCP/IP models

Addressing in network