CABLING LANs & WANs Module 5Semester I
Content • Cabling the LAN • Cabling the WAN
Objectives • Identify characteristics of Ethernet networks. • Identify straight-through, crossover, and rollover cables. • Describe the function, advantages, and disadvantages of repeaters, hubs, bridges, switches, and wireless network components. • Describe the function of peer-to-peer networks. • Describe the function, advantages, and disadvantages of client-server networks. • Describe and differentiate between serial, Integrated Services Digital Network (ISDN), digital subscriber line (DSL), and cable modem WAN connections. • Identify router serial ports, cables, and connectors. • Identify and describe the placement of equipment used in various WAN configurations.
Networking MediaCarry flow of information • Media Characteristics: • Cable length • Cost • Ease of installation • Susceptibility to interference • Media Types • Coaxial • Fiber Optic • Space • Category 5 unshielded twisted-pair cable (Cat 5 UTP) A subset of physical layer implementations for Ethernet LANs
Ethernet Media • Ethernet technologies can be used in a campus network in several different ways: • 10 Mbps at the user level to provide good performance. • 100 Mbps for clients or servers that require more bandwidth. • Fast or Gigabit Ethernet between backbone devices.
This is the Jack This is the Connector RJ-45 connectors
568B pin assignments – straight cable Transmit Data Tip +ve Transmit Data Ring -ve Receive Data Ring -ve Receive Data Tip +ve
Interconnecting Devices • Use straight-through cables for… • Switch to router • Switch to PC or server • Hub to PC or server • Use roll-over cables to… • Connect a terminal to a console port • Use crossover cables for… • Switch to switch • Switch to hub • Hub to hub • Router to router • PC to PC • Router to PC
Repeaters - Hubs Repeaters • A repeater regenerates and retimes network signals at the bit level to allow them to travel a longer distance • 5-4-3 Rule for 10-Mbps Ethernet should be used to limit latency • Too much latency on the LAN increases the number of latecollisions and makes the LAN less efficient Hubs • Hubs are actually multiport repeaters • Change the network topology from a linear bus to a star • Three basic types: • Passive – no boost, no clean and no power • Active - needs power to amplify the incoming signal • Intelligent - microprocessor chip and diagnostic capabilities
Bridges & Switches Bridges • Switches • Bridges and switches operate at the Data Link layer. • Destination MAC address is looked up in the bridge table to determine whether to filter, flood, or copy the frame onto another segment. • A switch has many ports with many network segments connected to them. • A switch chooses the port to which the destination device is connected. • Alleviates congestion in LANs by reducing the size of collision domains, reducing traffic and increasing bandwidth. • Two basic operations: • Switching data frames. • Build and maintain switching tables and search for loops. • Switches operate at much higher speeds than bridges and can support new functionality, such as virtual LANs.
Wireless • Much less cabling • RF, IR, laser, satellite, microwaves • The only cabling can be to the Access Points • The transmitter converts source data to EM waves • The receiver converts waves back into data • All devices in WLAN must have Wireless NICs IR weaknesses: • ‘Line of sight’ limitation (newer technologies combat this) • Signal weakening or obstruction by people or humidity RF technology works between rooms or even buildings RF weaknesses: • Single frequency is subject to outside interference and obstructions • Single frequency is easily monitored by others making it insecure FHSS and DSSS are Spread Spectrum technologies which add security and immunity to noise by using multiple frequencies
NIC • The function of a NIC is to connect a host device to the network medium • The NIC is also referred to as a network adapter • NICs are considered Layer 2 devices because each NIC carries a unique code called a MAC address
Peer-to-Peer • In a peer-to-peer network • networked computers act as equal partners, or peers • individual users control their own resources • Peer-to-peer networks are relatively easy to install and operate • A peer-to-peer network works well with 10 or fewer computers • peer-to-peer networks do not scale well, their efficiency decreases rapidly as the number of computers on the network increases • Security is difficult to maintain
Client/Server • In a client/server arrangement, network services are located on a dedicated computer called a server • The server is a central computer that is continuously available to respond to requests from clients for file, print, and application services • Servers are designed to handle requests from many clients simultaneously • The aggregation of resources on server systems brings greater security, simpler access and coordinated control, the server introduces a single point of failure
WAN Connections • Serial connections are used to support WAN services such as dedicated leased lines that run Point-to-Point Protocol (PPP) or Frame Relay
WAN • WANs use serial transmission • This is a process by which bits of data are sent over a single channel • This process provides reliable long distance communication and the use of a specific electromagnetic or optical frequency range • Signals transmitted over voice grade telephone lines use 3 kilohertz (kHz).
WAN • Serial connections are used to support WAN services such as dedicated leased lines that run Point-to-Point Protocol (PPP) or Frame Relay • ISDN offers dial-on-demand connections or dial backup services. • ISDN Basic Rate Interface (BRI) is composed of: • Two 64 kbps bearer channels (B channels) for data • One delta channel (D channel) at 16 kbps used for signaling and other link-management tasks • PPP is typically used to carry data over the B channels.
Router Connections • Cisco router physical connectivity is provided by serial connections: • The first type of serial connections is a 60-pin connector • The second is a more compact ‘smart serial’ connector • The provider connector will vary depending on the type of service equipment
DTE/DCE • When the connection is made directly to a service provider, or a device that provides signal clocking such as a channel/data service unit (CSU/DSU), the router will be a data terminal equipment (DTE) and use a DTE serial cable. • When the local router is required to provide the clocking rate it will use a data communications equipment (DCE) cable
Managing Routers • To initially configure the Cisco device, a management connection must be directly connected to the device • The console port allows monitoring and configuration of a Cisco hub, switch, or router • The cable used between a terminal and a console port is a rollover cable • also known as a console cable
http://www.webopedia.com ……. Continue next class, thank you
LABS 5.1.5 RJ-45 jack punch down 5.1.7 Hub & NIC purchase 5.1.10 Purchasing LAN Switches 5.1.12 Building a Peer to Peer network 5.1.13a Building a HUB based network 5.1.13b Building a Switch based network