Network Applications Resource sharing Computing Mainframe computer(old days) Today, computers cheaper than comm(except LANS) Printers, peripherals Information DB access and updates E.g., Financial, Airline reservations, etc. · Services Email FtP. Telnet, Web access Video conferencing DB access Client/server applications
Network Applications • Resource sharing – Computing – Mainframe computer (old days) Today, computers cheaper than comm (except LANS) Printers, peripherals – Information DB access and updates E.g., Financial, Airline reservations, etc. • Services – Email, FTP, Telnet, Web access – Video conferencing – DB access – Client/server applications Eytan Modiano Slide 6
Network coverage areas Wide Area Networks( WANs) Span large areas(countries, continents, world) Use leased phone lines(expensive!) 1980s:10Kbps,2000s:25Gbps User access rates: 56Kbps-155 Mbps typical Shared comm links: switches and routers E.g, IBM SNA, X 25 networks, Internet Local Area Networks(LANS) Span office or building Single hop(shared channel)(cheap User rates: 10 Mbps-1 Gbps E.g. Ethernet, Token rings apple-talk Metro Area networkS MANS) Storage area networks
Network coverage areas • Wide Area Networks (WANS) – Spa n large areas (countries, continents, world) – Use leased phone lines (expensive!) 1980’s: 10 Kbps, 2000’s: 2.5 Gbps User access rates: 56Kbps – 155 Mbps typical – Shared comm links: switches and routers E.g, IBM SNA, X.25 networks, Internet • Local Area Networks (LANS) – Spa n office or building – Single hop (shared channel) (cheap!) – User rates: 10 Mbps – 1 Gbps E.g., Ethernet, Token rings, Apple-talk • Metro Area networks (MANS) • Storage area networks Eytan Modiano Slide 7
Network services Synchronous Session appears as a continuous stream of traffic(e.g, voice) Usually requires fixed and limited delays Asynchronous Session appears as a sequence of messages Ty pically bursty E.g., Interactive sessions, file transfers, email Connection oriented services Long sustained session Orderly and timely delivery of packets E.g., Telnet, FTP Connectionless services One time transaction(e.g, email) Qos
Network services • Synchronous – Session appears as a continuous stream of traffic (e.g, voice) – Usually requires fixed and limited delays • Asynchronous – Session appears as a sequence of messages – Typically bursty – E.g., Interactive sessions, file transfers, email • Connection oriented services – Long sustained session – Orderly and timely delivery of packets – E.g., Telnet, FTP • Connectionless services – One time transaction (e.g., email) • QoS Eytan Modiano Slide 8
Switching techniques Circuit Switching Dedicated resources Packet Switching Shared resources Virtual circuits Datagrams
Switching Techniques • Circuit Switching – Dedicated resources • Packet Switching – Shared resources – Virtual Circuits – Datagra ms Eytan Modiano Slide 9