Lec. 5 Networks Hardware Components Dr. Eng. Samy Elmokadem Chapter 8 10/12/2017 1
internetworking devices used in backbone networks After studying this Chapter you should: Know which internetworking devices are used in backbone networks Chapter 8 10/12/2017 2
Definition Backbone Network (BN) - a large high-speed central network that connects all the terminals, microcomputers, mainframes, local area networks, and other communications equipment on a single company or site. Sometimes called a Campus Area Network (CAN). Use Higher speed circuits for connectivity. Chapter 8 10/12/2017 3
Definition شبكة االمؤسسات (EN) Enterprise Network a supernetwork that interconnects all of an organizations networks (LANs and WANs), regardless of whether it crosses state, national, or international boundaries. Chapter 8 10/12/2017 4
Why interconnect networks? Reliability Performance Security Chapter 8 10/12/2017 5
Need for Connectivity Devices Overcome the limitations of the LAN media Transport of data packets across multiple networks with different media access methods Communication between systems with incompatible protocols Chapter 8 10/12/2017 6
Backbone Network Components Two basic components to the BN hardware devices that connect the networks to the backbone hubs bridges switches routers brouters gateways network cable Chapter 8 10/12/2017 7
Hubs Hubs are special repeaters that overcome the electromechanical limitations of media signal path. very simple devices that pass all traffic in both directions between the LAN sections they link same or different cable types use physical layer protocols pass on every message used to connect LANs of similar technology, or to extend the distance of one LAN can be called repeaters or amplifiers There are three main types of hubs: passive, active, and intelligent. Chapter 8 10/12/2017 8
Type of Hub/Switch Dumb Using it Smart Using it & knowing the situation Make the decision Intelligent Using it, Knowing it & Controlling it Chapter 8 10/12/2017 9
Functions of hub: HUB Devices 1-Facilitate adding, deleting or moving work stations. 2-Extend the length of the network 3- It offers fault tolerance feature. 4- Provide centralize management services.. Repeater/Amplifier HUB (MAU) Chapter 8 10/12/2017 10
Repeater/Hub Physical Layer devices. Protocol Independent. Interconnect two or more network segments (with the same type) to be a larger network segment. Regenerates the received digital signals. Does not process the received frames Chapter 8 10/12/2017 11
Repeater/Hub Application Presentation Session Transport Network Data Link Physical Physical Application Presentation Session Transport Network Data Link Physical Physical Repeater Repeaters work at layer 1 of the OSI model Their primary function is to regenerate signal Chapter 8 10/12/2017 12
Shared Network Hub Hub 10Base5 Hub 10Base2 10BaseT 100BaseT Collision Domain CSMA/CD Share 10Mbps or 100Mbps Chapter 8 10/12/2017 13
Hubs inexpensive easy to Install can connect different media very little delay limited distance between devices limited on the number of repeaters no protocol or rate conversion no error detection does not filter Chapter 8 10/12/2017 14
Bridges connects two or more segments of similar networks or different networks ( LAN segments that use the same data link and network protocol ) operated at the data link layer same or different cable types forward only those messages that need to go out (filtering) learn whether to forward packets internal routing table combination of black box hardware and software Chapter 8 10/12/2017 15
Bridges There are three types of bridges: Simple bridge Learning bridge Multiport bridge Chapter 8 10/12/2017 16
Bridges Interconnecting Bridge Repeater/ Amplifier HUB (MAU) Repeater/ Amplifier HUB (MAU) Chapter 8 10/12/2017 17
Bridges may be different data rates and different media easy to Install no modifications required to the communications software can learn the ports for data transmission understand only data link layer protocols and addresses no protocol conversion broadcasts when it does not know the address Chapter 8 10/12/2017 18
Switches connect more than two LAN segments that use the same data link and network protocol. operate at the data link layer same or different type cable ports are usually provided for 4, 8, 16, or 32 LAN segments ports are used simultaneously connect lower speed segments to high speed BN Chapter 8 10/12/2017 19
Switches Cut-through switches use circuit-switching to immediately connect the port with the incoming message to the correct outgoing port very fast as decisions are done in hardware outgoing packet is lost if port is in use Store-and-forward switches copy the incoming packet to memory prior to processing the destination address -- transmit it when the outgoing port is ready Chapter 8 10/12/2017 20
Switches Interconnecting Wing A Wing B First Floor Switch Wing C Wing C Chapter 8 10/12/2017 21
Switches much more sophisticated than previously أكثر تطورا من ذي قبل enable all ports to work at the same time can convert protocols قابل للتكوين Configurable high speed understand only data link layer protocols and addresses much more expensive then previous options higher maintenance Chapter 8 10/12/2017 22
Bridge/Switch MAC Layer devices Protocol Independent Interconnect two or more LANs Process received frames based on the MAC addresses Addressed Learning, Frames Filtering & Forwarding Function Increase the total throughput of a LAN Chapter 8 10/12/2017 23
Bridge/Switch Application Presentation Session Transport Network Data Data Link Link Physical Physical Bridge Application Presentation Session Transport Network Data Data Link Link Physical Physical Bridges work at layer 2 of the OSI model Their primary function is to relay frame Chapter 8 10/12/2017 24
Routers connect two or more LANs that use the same or different data link protocols, but the same network protocol. same or different cable types operate at the network layer forward only messages that need to go out routers use the internetwork address (IP addresses) Use internal routing tables to determine the shortest path to destination only processes messages addressed to it Chapter 8 10/12/2017 25
Routers choose the best route to send the packet (path) IDs of other networks paths to the networks relative efficiency of the paths Chapter 8 10/12/2017 26
Routers The router must deal with network differences: addressing schemes minimum packet size interfaces reliability Chapter 8 10/12/2017 27
Routers Interconnecting Router X.25 Network \ the cloud Ethernet LAN2 Token Ring LAN1 Chapter 8 10/12/2017 28
Router/Layer 3 Switch Router Broadcast Domain Broadcast Domain Chapter 8 10/12/2017 29
Router/Layer 3 Switch Application Presentation Session Transport Network Network Data Data Link Link Physical Physical Router Application Presentation Session Transport Network Network Data Data Link Link Physical Physical Router work at layer 3 of the OSI model Their primary function is to route packet Chapter 8 10/12/2017 30
Routers can mix-in-match protocols and convert them enable all ports to work at the same time can be used as an extra layer of security configurable high speed hard to configure and manage access lists must be kept current high maintenance / high training costs very expensive Chapter 8 10/12/2017 31
Brouters devices that combine the functions of both : bridges and routers operate at both the data link and network layers same or different data link protocol same network protocol as fast as bridges for same data link type networks Chapter 8 10/12/2017 32
Comparison between Router and Bridge S. N. Router Bridge 1 Operates the networ layer of OSI model Operates the data link layer of OSI model 2 Routers are reltively expensive Bridges are relatively inexpensive 3 Difficult to setup and configure Relatively easy to configure 4 Focuses on protocol address Focuses on MAC address 5 Router can accommodate multiple paths 6 Can route packets to reduce network bottlenecks Bridge can accommodate single path Filter packets faster than routers 7 Joint two different networks Extends the existing networks Chapter 8 10/12/2017 33
Gateways complex machines that are interfaces between : two or more dissimilar networks (connect independent networks ) connect two or more LANs that use the same or different data link layer, network layer, and cable types Operate in all layers of the OSI model. forwards only those messages that need to go out a combination of both hardware and software Chapter 8 10/12/2017 34
Gateways translates one network protocol ( e.g. TCP/IP ) to another translates data formats ( e.g. Apple Talk ) before forwarding it. translates open sessions between application programs translates to mainframes Chapter 8 10/12/2017 35
Gateways Exists in four major types: LAN-to-IBM mainframe Network-to-network System-to-network System-to-system Chapter 8 10/12/2017 36
LAN-to-IBM Mainframe Allow LANs using TCP/IP and Ethernet to be connected to IBM mainframe using SNA Eliminates the need for each PC on the LAN to have SNA hardware/software that makes it act like an IBM 3270 terminal Mainframe Gateway Chapter 8 10/12/2017 37
Network-to-Network X.75 Gateway X.25 \ Network A X.25 Network \ B X.75 provides terminal address translation Chapter 8 10/12/2017 38
System-to-Network Gateway X.25 \ Network Minicomputer or Microcomputer Chapter 8 10/12/2017 39
System-to-System allows connecting one vendor s architecture to another vendor s architecture allows both the existence of OSI-based and proprietary architectures (like SNA or AppleTalk) gives management to tools necessary to plan a gradual migration to a completely OSI environment applications can work with other application Chapter 8 10/12/2017 40
System-to-System Profs E-mail Gateway \ X.25 Network LAN E-mail Server LAN E-mail Gateway Profs E-mail Chapter 8 10/12/2017 41
THE END Chapter 8 10/12/2017 42