LAN, WANs and More

LAN

• Switch

• Router

• Server Farm

• Wireless Access

• High Speed Connectivity

• Firewall

• Local Control

• Gateway

MAN

• Connecting LANs

• High Speed

• Point to point connection

• Dedicated cable

• Wireless Beam

• Infra Red or laser

• Normally restricted to a small geographical area

• Otherwise similar to LAN

WAN

• International

• Lower Speeds

• Internet technologies used

• Cloud computing

• Less or no control

• PPTP (Point to Point Tunnelling Protocol)

• VLAN technologies

• Encryption

Video: WAN, Man and LAN

• https://www.youtube.com/watch?v=Z8sqPruWG6Y

PSTN and LAN

• PSTN Public Switched Telephone Network

• Bandwidth: 300Hz to 3.4kHz

• Cables were optimised for analogues telephony

at low f

• On the pure PSDN system data speeds of

56kbps were achieved

• New technologies improved the capacity of 50s

infrastructure by introducing broadband

• PSTN WANs are still used for extreme situations

PSTN Circuit used as a backup

connection

ADSL: Old and modern technology

combined

VOIP replacing PSTN

802.3 – Ethernet Standard

"Grandaddy" of the 802 specifications. Provides asynchronous networking using "carrier sense, multiple access with collision detect" (CSMA/CD) over coax, twisted-pair copper, and fiber media. Current speeds range from 10 Mbps to 10 Gbps.

Ethernet

• CSMA/CDcarrier sense multiple access with collision detection

• Analogy:crossroads without any rules and driving blindly into it

• Weakness of the standard in generating collisions has been alleviated through Data Switch technologies

802.5 Token Ring Standard

• The original token-passing standard for twisted-pair, shielded copper cables. Supports copper and fiber cabling from 4 Mbps to 100 Mbps. Often called "IBM Token-Ring."

Token Ring

• The ring is actually established in an MSAU – multi station access unit

• The unit looks like a switch or a hub

• Speeds are only 4 Mbps and 16Mbps

• The standard has been less used in the 90s with the advent of data switches.