Dr. Beinschróth József Telecommunication informatics I. Part 4 ÓE-KVK Budapest, 2019. Dr. Beinschróth József: Telecommunication informatics I. Content Network architectures: collection of recommendations The Physical Layer: transporting bits The Data Link Layer: Logical Link Control and Media Access Control Examles for technologies based on the Data Link Layer The Network Layer 1: functions and protocols The Network Layer 2: routing Examle for technology based on the Network Layer The Transport Layer The Application Layer Criptography IPSec, VPN and border protection QoS and multimedia Additional chapters Dr. Beinschróth József: Telecommunication informatics I. 2 The content of this chapter Wired LAN-s Wireless LAN-s Bluetooth PLC, BPL (Power Line Communication, Broadband over Power Lines) DOCSIS Dr. Beinschróth József: Telecommunication informatics I. 3 The LAN (Local Area Network) architecture covers the first two layer of the model The LAN technology is very widespread Covers the first two layer of the model, The data link layer plays a decisive role in the LAN architecture. Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 4 The LAN is implemented in buildings or buildings close to each other (1) Located within a relatively small range of intelligent devices: the physical dimension limit: max. a few km, the transmission time is known in advance (micro, nanosecond scale delays). Typically is implemented in buildings, buildings close to each other, companies, institutions. The data transfer is implemented in a communication channel (does not use connected or leased telephone or data networks) Typically private network - work with one owner and administrative management. Destination: computers, printers and other shared resources sharing, messaging. Typically multiple access. Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 5 The LAN is implemented in buildings or buildings close to each other (2) The stations in the physical layer are shared. (Multiple Access) The LANs basically differ in media access control solution. There are various topologies. 10-100-1000Mbps data transfer speed, the transmission time is limited. The network traffic control is based on the principle of peer communication (no special equipment). Physical medium: coax (old), UTP, optical fiber, (wireless) Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 6 The LAN is made up of many elements Computer equipments (servers, workstations, printers, etc.) Network interface controller Network elements • Active elements (repeater, router, HUB, switch…) • Passive elements (cablesystem, connectors, cable organizers…) Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 7 LANs offer many advantages (1) Distributed data access. A user can access a file which is stored on another computer or files can be stored on a different machine. Problem: access at the same time. Other network resources (typically printers) used by multiple users. The asset utilization increases (not necessary printer for all the users, every user can access for the expensive printers). Message forwarding between users. Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 8 LANs offer many advantages (2) E-mail, messaging commands. License management optimization. Appropriate license is required only in the number of concurrent users. Optimizing operation. Any available PC configuration databases (user data), remote access. Fault tolerance, reliability growth. Achieved by using redundancy to a device failure does not mean a loss of service (printer, server…). … Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 9 Many standards applies to the LAN IEEE 802 standards 802.1 High level Interface 802.1p General Registration Protocol 802.1q Virtual Bridged LANs 802.2 Logical Link Control 802.3 Carrier Sense Multiple Access/ Collision Detect (CSMA/CD) 802.3u Fast Ethernet 802.4 Token-Passing Bus 802.5 Token-Passing Ring 802.6 Metropolitan Area Networks 802.7 Broadband Technical Advisory Group 802.8 Fiber Optic Technical Advisory Group 802.9a IsoENET 802.9 Integrated Voice and Data Networks 802.10 Network Security (802.11 Wireless LAN-s) Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 10 Special LAN – virtual LAN (vLAN) • The individual stations are not close to each other, are typically connected via the Internet, but they behave as if they were in a LAN. • The stations are logically organized into a group. (vLAN) • (In case of LAN the together used physical v=virtual medium connected the stations.) • The vLAN is considered to be a broadcast domain. • Logical grouping can be based on MAC address, IP address, protocol type, port number, etc. Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 11 The IEEE LAN standards mapped to the bottom two layers of the OSI model OSI Reference Contact between IEEE LAN standards and the Model OSI Reference Model Model Network LAN Architecture 802.2 Logical Link Control Data Link 802.3 802.5 Media Access Media Access Physical Medium Access sublayer Control Control Physical Physical Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 12 LANs can be either star, ring or bus topology Structured cabling: apparently star topology Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 13 Several technologies exist for LAN IEEE Ethernet 802.3 Token Passing The Ethernet and the IEEE 802.3 are not the same. The Ethernet is a product of XEROX which is practically the implementation of the IEEE 802.3 (apart from minor differences). Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 14 IEEE Ethernet 802.3 Token The Ethernet technology is widely used Passing Ether: hypothetical medium is necessary for the propagation of electromagnetic waves. The most common dominant LAN implementation (since 1970) Reliable, cost-optimized, flexible, requires minimal maintenance. Well suited to TCP/IP Reasons for its popularity • Compatible with different speed limits. • Open standards. • Simple and cheap to implement. • Good fit for data networks. Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 15 IEEE Ethernet Ethernet is continuously evolving 802.3 Token preserving compatibility with old versions Passing Continuously evolving ,preserving compatibility with old versions. Development began in the Xerox. DIX Ethernet standard (Digital, Intel, Xerox): 10 Mbps. Az IEEE 802.3 came from DIX Ethernet. Versions (data transfer speeds): • Classic Ethernet (10Mbps – 1980.; IEEE 802.3 – 1983.). • Fast Ethernet (100Mbps; IEEE 802.3u -1995.). • Gigabit Ethernet (1000Mbps; IEEE 802.3 ab, z – 1998.). • 10 Gigabit Ethernet (10Gbps – IEEE 802.3 ak, ae - 2004.). Ethernet SNAP (SubNetwork Access Protocol) – eliminate the shortcomings of 802.3 – compatible. Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 16 IEEE Ethernet 802.3 Token There are several Ethernet versions Passing Type Denomination Cable Max. length Junction/ Comment segment 10Base5 Thick coaxial 500m 100 Original Traditi- 10Base2 Thin coaxial 185m 30 onal 10BaseT Twisted pair 100m 1024 Cost optimal Ethernet 10BaseF Optical cable 2000m 1024 Between buildings 100BaseT4 Twisted pair 100m 100 Cat3 UTP Fast 100BaseTX Twisted pair 100m 100 Cat5 UTP Ethernet 100BaseFX Optical fiber 2000m 2000 Point-to-point 1000BaseSX Optical fiber 550m Gigabit 1000BaseLX Optical fiber 5000m Ethernet 1000BaseCX 2 pair STP 25m 1000BaseT 4 pair UTP 100m Cat5 UTP 10 10GBaseCX4 Gigabit 10GBaseT Ethernet 10GBase-LRM Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 17 IEEE Ethernet 802.3 Token 10Base5: classic solution Passing 10Base5: The original Ethernet configuration (thick Ethernet (802.3)– cable diameter: 0,5”) Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 18 IEEE Ethernet 802.3 Token 10Base5: distance up to max. 500m Passing • Thick Ethernet Name, standard • 10 Mbps, baseband transmission, max. 500 m • IEEE 802.3 • Bus Topology • The transceiver separate unit • Coax, thick, rigid, 0,5”, close: 50 Ohm Cable, connector • „vampire” connector, 2,5 m per branch is not allowed • Manchester Coding • Bit period: 100ns Endpoints • Max. 100 • There are placing signs for the connectors Comment • Outdated solution Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 19 IEEE Ethernet 10Base5: computers connected to networks via 802.3 Token transceiver Passing Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 20 IEEE Ethernet 10Base2: computers connected to the network via 802.3 Token T connectors (1) Passing Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 21 IEEE Ethernet 10Base2: computers connected to the network via 802.3 Token T connectors (2) Passing Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 22 IEEE Ethernet 802.3 Token 10Base2: distance up to cc. 200m Passing • Thin Ethernet Name, standard • 10 Mbps, baseband transmission, max. 185 m • IEEE 802.3a • Bus Topology • The transceiver unit is not a separate device: the interface card is included. • Coax, thin 0,25”, close: 50 Ohm Cable, connector • Branch with T connectors • Manchester Coding • Bit period:100ns • Max. 30 Endpoints • Can’t connect new endpoint without interruption in operation. • Easy to use, flexible cable, tear sensitive Comment • Outdated solution Wired LAN-s Dr. Beinschróth József: Telecommunication informatics I. 23 IEEE Ethernet 802.3