Chapter 8 – Data switching and routing Data different than voice Already digital – voice must be converted to digital from analog Can tolerate delay usually – voice can’t tolerate delay Continuous stream or bursts – voice is a stream Data can flow at any speed – digitized voice is based on 64kbps Data highly susceptible to errors – voice not so much Data uses many protocols Data Packets Header and payload Connection-oriented Connectionless-oriented
Chapter 8 – Data switching and routing
Chapter 8 – Data switching and routing
Chapter 8 – Data switching and routing Open Systems Interconnect Model (OSI)
Chapter 8 – Data switching and routing
Chapter 8 – Data switching and routing Internet Protocol (IP) Layer 3 of OSI Model Connectionless packet standard – very flexible IPv4 and IPv6 IPv4 Packet structure
Chapter 8 – Data switching and routing IP routing not routeing
Chapter 8 – Data switching and routing Routers Routers connect LAN’s forming a WAN Static routing Routing protocol AS – autonomous system – network of routers owned by one organization AS routing Interior Gateway Protocol (IGP) – routing within an AS Exterior Gateway Protocol (EGP) – routing between AS
Chapter 8 – Data switching and routing IP doesn’t provide data transfer well at layer 3 Transport Layer 4 used for data transfer Transmission Control Protocol (TCP) Connection-oriented User Datagram Protocol Connectionless-oriented TCP numbers IP packets (datagrams) at sending and receiving endpoints Orders them correctly Request retransmission of packets if needed Monitors flow rate of packets
Chapter 8 – Data switching and routing
Chapter 8 – Data switching and routing UDP connectionless No retransmission No delay Better suited for voice and video Web page request – OSI layers
Chapter 8 – Data switching and routing
Chapter 8 – Data switching and routing The “Internet” is a collection of IP networks connecting to each other – not one single public Internet backbone Based on consortium of users, academics, and data equipment manufacturers – Internet Engineering Task Force (IETF) Originated (ARPANET) US Dept. of Defense 1960s TCP added in 1983 – information sharing HTTP – world wide web – 1991 Multiple Tier one providers own networks Tier 2, 3, etc. providers Peering points Public Private Internet of Things (IOT)
Chapter 8 – Data switching and routing Voice over IP (VoIP) Very useful for business with multiple locations
Chapter 8 – Data switching and routing
Chapter 8 – Data switching and routing Wide Area Network (WAN) Types Private Line Dedicated full bandwidth end to end Can run any protocol on the circuit Expensive Many circuits to manage at HQ Virtual Private Network (VPN) Uses public internet Tunnel created back to HQ site Software client for remote user Encrypted for security Scaleable
Chapter 8 – Data switching and routing Multi-protocol Label Switching (MPLS) Shared backbone connection (but not over public internet) Routers use labels on IP packets to create a “virtual path” through the network Fast switching through network Can scale to many sites One circuit to manage at HQ site
Chapter 8 – Data switching and routing Local Area Network (LAN)
Chapter 8 – Data switching and routing Ethernet Carrier-sense multiple-access with collision detection (CSMA/CD) Wireless LAN
Chapter 8 – Data switching and routing Cloud Computing