Cisco Certified Network Associate Cisco Networking Academy Turku Polytechnic
CCNA1 – Module 2 - history • Evolution from PC to shared resources – Sneaker net – LAN – WAN
• • • • •
1969 Arpanet, »1990 the Internet 1973 development of TCP/IP starts 1982 OSI-model 1983 TCP/IP overtake the Internet 1993 first graphics-based browser, Mosaic
CCNA1 – Module 2 - LAN and WAN • • • •
Computer NIC End-user devices Networking media – Medium and topology • Physical and logical topology (broadcast and token passing)
• Network devices
CCNA1 – Module 2 – new techniques • MAN – Metropolitan Area Network • SAN – Storage Area Network • VPN – Virtual Private Network – Access VPN – Intranet VPN – Extranet VPN
CCNA1 – Module 2 - Bandwidth • • • •
It’s finite It’s not free Demand for it is ever increasing It’s key factor when analyzing network performance • Units and limitations – bps (limited by medium)
CCNA1 – Module 2 Throughput • Always less than bandwidth • Affecting variables – – – – – – –
PC (client) the server Other users on the LAN Routing within the cloud Topology of the LAN Type of data time of day
CCNA1 – Module 2 – Throughput calculation • Best download T=S/BW • Typical download T=S/P – BW = maximum theoretical bandwidth of the slowest link between hosts in bps – P = measured throughput of data transmission in bps – T = Time for file transfer in seconds – S = file size in bits
CCNA1 – Module 2 Networking models • Peer to peer communication • OSI-model – 7 layers
• TCP/IP-model – 4 layers
• Data encapsulation
Physical topology
MAN
SAN
VPN
Peer to Peer
OSI
TCP/IP
Data encapsulation