1 OVERVIEW OF LAN Training Division, NIC New Delhi
2 LAN Overview What is LOCAL Area Network? Any device whose resources can be share and controlled
3 Which device can be connected : 1. Any device,which has a interface 2. Has a software to control its operation What is interface? Serial, Parallel, Ethernet,ATM, Packet Switch, etc Telnet, http,snmp, SMPT etc are application to access / control the resources.
5 LAN Topologies : 1. Bus : 10base2,10base5 2.Star : 10base-T,100bassTx, 3. Ring : FDDI, Token Ring, RS232 connection RS232 connection BUS Topology (Thick Ethernet ) STAR Topology (UTP Ethernet )
6 Ring Topology (FDDI ) Ring Topology (Token Ring)
7 Ethernet 1. Ethernet Overview 1.1 Definition : Ethernet is defined as protocol using Carrier Sense Multiple Access with Collision Detection (CSMA/CD). It supports data transmission rate of 10 Mb/s using Coaxial, Twisted pair or Fiber optic. Other versions of Ethernet is Fast Ethernet and Gigabit Ethernet, supporting 100 Mb/s and 1000Mb/s respectively. It comes in the 1 st and 2 nd Layer of OSI model. 1.2 History : It was first developed by Xerox in 1970 to connect Computers with Printers. Later in 1979, DEC, Intel and Xerox joined hand for its standardization and formally released on The 1 st IEEE standard was released on 1983 as IEEE Later other improved version were developed for different media..ieee 802.3a is for Thin Ethernet or 10Base2 for cheaper coaxial cable..ieee 802.3I or 10Base-T for twisted pair cable..ieee 802.3d or 10Base FL Fiber Optic cable..ieee 802.3x or 1000Base-X for full duplex connection.ieee 802.3ab or 1000Base_T is the latest standard for 1Gb/s speed on UTP Cat5 cables.
8 1.3 Ethernet Standards: 10Base2/IEEE 802.3a: This supports data rate up to 10 Mb/s through thin coaxial cable for maximum distance of 185 m. 10Base5 : This is for Thick cable and supports up to 500 m. 10Base-T/IEEE802.3I :This supports data rate up to 10 Mb/s through UTP cable for maximum distance of 100 m. IEEE802.3u :This version is called Fast Ethernet and supports data rate up to 100 Mb/s through : a) 100Base-TX on two pair UTP Cat 5 cable for maximum distance of 100 m,. b) 100Base-T4 on four pair UTP Cat 3 cable for maximum distance of 100 m,. c) 100Base-FX on one pair Multi-mode Fiber Optic Cable up to 2000m. 1000Base-X or IEEE 802.3z : This version is called Gigabit Ethernet and support three types of media as Single mode, Multi mode Fiber Optic cable and STP cable 1000Base-T or IEEE 802.3ad is for 1Gb/s over 4 pairs of UTP cables up to 100 m.
9 Ethernet Media Access Control There are two type of topology in Ethernet one Bus and Star structure. The 10Base2 and 10Base5 are traditional Bus structure which operates only in half duplex transmission. 10Base T and 100Base-tx are Star topology supports full as well as half duplex transmission. 1. Half Duplex 2.Full Duplex 3. VLAN 4. Multilink Trunking 5. Layer 3 Switch
10 Half Duplex Ethernet : TX or RX at a time with 10 MBPS data speed Full Duplex Ethernet : TX and RX simultaneously with 10 MBPS effective speed 20MBPS
11 Full Duplex Fast Ethernet : TX and RX simultaneously with 100 MBPS effective speed 200MBPS Multilink Trunking : Both the links works simultaneously with 200 MBPS effective speed 400MBPS
12 VLANs are technology which groups ports into VLANs into broadcast domains.this is a way to logically divide the switch. The packets, IP multicast, unicast frames can be forwarded to the ports of same VLAN. 2 nd Floor VLAN 1 Switch VLAN 2 Hub Hub VLAN 2 1 st Floor Switch Gnd Floor VLAN 1 Servers Backbone Switch VLAN 2 Hub VLAN 1 Hub VLAN 2
13 1.5 Multilink Trunking This technology allows to group many ports into one link together to increase the bandwidth and throughput between the devices. 2nd Floor Backbone Switch Trunk 2 400Mbps 2nd Floor Backbone Switch Trunk 1 400Mbps Servers Gnd Floor Backbone Switch Servers
14 Layer 3 Switch LAN segment 2 2 nd Floor Switch Hub Hub 1 st Floor Gnd Floor Switch Router Hub Servers LAN segment 3 LAN segment 4 LAN segment 1 Hub
15 Layer 3 Switch LAN segment 2 2 nd Floor Switch Hub Hub 1 st Floor Gnd Floor Switch L3 Switch Hub Servers LAN segment 3 LAN segment 4 LAN segment 1 Hub
16 1.5 Multilink Trunking This technology allows to group many ports into one link together to increase the bandwidth and throughput between the devices. 2nd Floor Backbone Switch Trunk 2 400Mbps 2nd Floor Backbone Switch Trunk 1 400Mbps Servers Gnd Floor Backbone Switch Servers
17 Ethernet Physical Layer Specifications. Brief summary of various physical layer specification defined in Ethernet is as follows Base Base Base-T Base-FL Base TX Base FX Base X
18 Base-5 Transmission Rate Cable Type 10 Mb/s (full-duplex not supported) A single "thick" (10mm) coaxial cable with 50 ± 2 ohms impedance, Supports bend radius of 2.54 cm (10 inches), Eg. Belden part numbers 9880 (PVC) & (plenum rated) Maximum Segment Length 500 meters (1640 feet) Maximum Transceiver Cable (AUI) Length 50 meters (164 feet) Maximum Number of Transceivers per Segment 100 Connector Technology N-type coaxial connectors, barrel connectors, & terminators Signal Encoding Manchester encoding
19 2.2 10Base2 10Base2 supports a 10 Mb/s transmission rate over "thin" (5mm) coaxial cable. Transmission Rate 10 Mb/s (full-duplex not supported) Cable Type A single "thin" (5mm) coaxial cable with 50 ± 2 ohms impedance, G58A/U or RG58C/U, Supports bend radius of 5 cm (2 inches), Belden part numbers 9907 (PVC) & (plenum rated) Maximum Segment Length 185 meters (606.9 feet) Minimum Spacing Between Stations 0.5 meters Maximum Number of Transceivers per Segment 30 Connector Technology BNC Tee coaxial connectors, barrel connectors, & terminators Signal Encoding Manchester encoding
20 Base-T Transmission Rate 10 Mb/s (20 Mb/s in optional full-duplex mode) Cable Type two pairs of Category 3 or better unshielded twisted pair (UTP) cabling,also known as voice grade or telephone twisted pair cabling,100-ohm impedance rating AMP, Lucent etc. Maximum Segment Length 100 meters (328 feet) Maximum Number of Transceivers per Segment 2 Connector Technology RJ-45 style modular jack (8-pins Signal Encoding Manchester encoding
21 2.4 10Base-FL 10Base-FL ("fiber link") supports a 10 Mb/s transmission rate over two fiber optic cables. The 10Base-FL standard updates and expands the prior Fiber Optic Inter-Repeater Link (FOIRL) standard. 10Base-FL supports a maximum segment length of 2000 meters compared with 1000 meters supported by FOIRL. 10Base-FL may be used to connect two switch, two repeaters, or a computer and a repeater port. All 10Base- FL segments are point-to-point with one transceiver on each end of the segment. The transceiver attaches to the two fiber optic cables through connectors that are commonly known as "ST". One fiber optic cable is used to transmit data, and the other is used to receive data. The fiber optic cable typically used with 10Base-FL is multi-mode fiber (MMF) known as "62.5/125". The wavelength of light used with 10Base-FL is 850 nanometers. In addition to supporting longer segment lengths, fiber optic cables are immune to electrical hazards such as lightning strikes and ground currents that can occur when connecting separate buildings. Fiber is also immune to electrical noise that can be generated by motors or other electrical equipment. Transmission Rate 10 Mb/s (20 Mb/s in optional full-duplex mode Cable Type two multi-mode fiber optic cables (MMF), typically 62.5/125 fiber, (62.5 micron fiber core with 125 micron outer cladding) 850 nanometer light wavelength Maximum Segment Length 2000 meters (6561 feet) Maximum Number of Transceivers per Segment 2 Connector Technology ST connector Signal Encoding Manchester encoding
22 Base-TX 100Base-TX supports a 100 Mb/s transmission rate over two pairs twisted pair cabling. It uses one pair of wires for transmitting data, and the other pair for receiving data. The two pairs of wires are bundled into a single cable that may often include two additional pairs of wires. If present, the two additional pairs of wires must remain unused since 100Base-TX is not designed to tolerate the "cross talk" that can occur when the cable is shared with other signals. Each end of the cable is terminated with an 8 position RJ-45 connector, or "jack". It supports transmission over up to 100 meters of 100 ohm Category 5 unshielded twisted pair (UTP) cabling. 100Base-TX transmits data using the "4B/5B" signal encoding scheme. The 100Base-TX standard supports the option of using 150 ohm shielded twisted pair (STP) cabling. Transmission Rate Maximum Segment Length 10 0Mb/s (200 Mb/s in optional full-duplex mode) Cable Type two pairs of Category 5 unshielded twisted pair (UTP) cabling,100-ohm impedance rating, (Optionally supports 150 ohm shielded twisted pair (STP) cabling) 100 meters (328 feet) Maximum Number of Transceivers per Segment 2 Connector Technology RJ-45 style modular jack (8-pins) for UTP cabling (Optionally supports 9-pin D-type connector for STP cabling) Signal Encoding 4B/5B
23 Base-FX 100Base-FX supports a 100 Mb/s transmission rate over two fiber optic cables. It allows maximum segment lengths of 412 meters for half-duplex links, and 2000 meters or more for full-duplex links. Even longer distances can be supported with the more expensive single mode fiber (SMF). 100Base-FX is essentially a "fiber" version of the 100Base-TX standard. The twisted pair cabling and connectors used in 100Base-TX components are replaced with fiber optic cabling and connectors in 100Base-FX components. Both standards use the same 4B/5B signal encoding scheme. The fiber optic cable typically used with 100Base-FX is multi-mode fiber (MMF) known as "62.5/125". The wavelength of light used with 100Base-FX is 1300 nanometers. The 100Base-FX standard allows several types of fiber optic connectors to be used. Duplex "SC" connectors are recommended, but "ST" and FDDI "MIC" connectors are also permitted. Transmission Rate 100Mb/s (200 Mb/s in optional full-duplex mode) Cable Type two multi-mode optical fibers (MMF), typically 62.5/125 multi-mode fiber,1300 nanometer light wavelength Maximum Segment Length Half-Duplex: 412 meters (1351 feet) Full-Duplex: 2000 meters (6561 feet) Maximum Number of Transceivers per Segment 2 Connector Technology duplex SC connector preferred, ST connector and FDDI MIC connector also permitted Signal Encoding 4B/5B
24 Base-X The identifier "1000Base-X" refers collectively to the 1000Base-LX, 1000Base-SX, and 1000Base-CX "Gigabit Ethernet" standards described in the following sections. Each of these standards are based on physical layer specifications adopted for Fibre Channel. In particular, 1000Base-X uses the same "8B/10B" coding scheme as Fibre Channel, and similar optical and electrical specifications. With 8B/10B signaling, every 8-bits of user data are converted into a 10-bit symbol prior to transmission over the media. The overhead associated with the extra bits requires that a signal transmission rate of 1.25 gigabaud be used to transfer a net 1 Gb/s of user data. The 1000Base-X standard defines a Gigabit Media Independent Interface (GMII) that attaches the Media Access Control (MAC) and Physical Layer (PHY) functions of a Gigabit Ethernet device. GMII is analogous to the Attachment Unit Interface (AUI) in 10 Mb/s Ethernet, and the Media Independent Interface (MII) in 100 Mb/s Ethernet Base-LX The "L" in 1000Base-LX stands for "long" as it uses long wavelength lasers to transmit data over fiber optic cable. The long wavelength lasers specified by the standard operate in the wavelength range of 1270 to 1355 nanometers. Both single mode and multi-mode optical fibers are supported. Long wavelength lasers are more expensive than short wavelength, but have the advantage of being able to drive longer distances.
25 Transmission Rate 1000 Mb/s (2000 Mb/s in optional full-duplex mode) Cable Type two 62.5/125 or 50/125 multi-mode optical fibers (MMF), or two 10 micron single mode optical fibers (SMF), 1270 to 1355 nanometer light wavelength Maximum Segment Length Half-Duplex MMF & SMF: 316 meters (1036 ft) Full-Duplex MMF: 550 meters (1804 ft) Full-Duplex SMF: 5000 meters (16,404 ft) Maximum Number of Transceivers per Segment 2 Connector Technology duplex SC connector Signal Encoding 8B/10B
26 3 Ethernet Switch Ethernet Hub receives a packet in one port and repeats it to all the ports, this allows all the machines to share the medium and communicate one at a time. In case of Switch the packets are forwarded to only the port in which machine is connected. Thus the medium is shared by multiple systems at a time. The functions of Ethernet switch has been improved drastically from 10 Mb/s half duplex to 1 Gb/s full duplex. Many new features are added as VLAN, tunneling, filtering etc. The architecture of Switches have been changed store and forward to cut through, or a combination of both. The functionality and the performance of the switch are compared by the following parameters. 1. Architecture : whether cut-through or store and forward. 2. Physical functionality : on the basis of number and type of ports, up gradability, type of uplink etc. 3. Logical functionality : on the basis of type and level of filtering, broadcast / multicast / runt packets. 4. VLASN support: No. of VLANs, Type of VLASN support Port wise, MAC, service etc. 5. Manageability : Levels of RMON and SNMP supported 6. Latency : Backplane speed and forwarded speed. 7. MAC address Table size : The application of the switch mostly depends upon the size of MAC table.
27 The Switches can be grouped into the following types according to the application : Desktop switch : these are used for connecting Client directly. The size of MAC table is small. 2. Work group switch : these are used to connect hubs/ desktop switches to the backbone network. Usually their one or more uplink ports with MAC table size more than 500 entries. Other features as VLAN, filtering. 3. Backbone switch : these are used for connecting different LANs. The backbone switch should have high latency table, medial independent port, large MAC table size, hot swappability, redundant power supply. Configuring the Baystack /100/1000 Switch. Configuration task : 1.connect a console to a Terminal ( 9600 baud, no parity, 8 bits, 1 stopbits ) using the DB-9 pin RS232 straight cable. 2. From the Main menu,select IP Configuration/Setup.. Enter the IN-Band IP address, Subnet Mask and default gateway. 3.From the Main menu, Select the SNMP Configuration.. There are 4 Traps, provide IP address of the SNMP Station one by one. This is the minimum configuration required to access the switch from the SNMP station. To check try to telnet from the SNMP Station to the switch. If you get the login prompt then the basic configuration is OK. For special configuration as VLAN, Trunking, etc, select Switch Configuration from the Main menu.
28 Configuring the Baystack /100/1000 Switch. Configuration task : 1.connect a console to a Terminal ( 9600 baud, no parity, 8 bits, 1 stopbits ) using the DB-9 pin RS232 straight cable. 2. From the Main menu,select IP Configuration/Setup.. Enter the IN-Band IP address, Subnet Mask and default gateway. 3.From the Main menu, Select the SNMP Configuration.. There are 4 Traps, provide IP address of the SNMP Station one by one. This is the minimum configuration required to access the switch from the SNMP station. To check try to telnet from the SNMP Station to the switch. If you get the login prompt then the basic configuration is OK. For special configuration as VLAN, Trunking, etc, select Switch Configuration from the Main menu., Select Switch configuration
29 VLAN Configuration Examples The Network diagram There are two User groups in VLAN 1 and VLAN2, who access the application Servers Server 1 and Server 2 respectively. The Mail servers and the Router for WAN connection is accessed by all, and is member of VLAN3. The two Back bone 350 switches are connected through multi link trunks. The configuration includes. 1. Configuring Backbone switches SWB1 and SWB2. \SWB1 : ports 1,5,7,11are untagged member of VLAN1 with PVID of port 1 & 11 is= 1 SWB2: ports 2,5,7,12 are untagged member of VLAN 2 with PVID of port 2 & 12 is =2 ports 1,2,5,7,11 & 12 are untagged member of VLAN 3 with PVID of port 5 & 7 is =3 ports 1,2,3,5,7,9,11 & 12 are untagged member of VLAN1 with PVID of port 3,5,7, & 9 is =1 ports 1,2,4,6,8,10,11&12 are untagged member of VLAN 2 with PVID of port 4,6,8 & 10 is =2 ports 1,2,3,4,5,6,7,8,9,10,11 & 12 are untagged member of VLAN 3 with PVID of port 1,2,11& 12 is =3
30 To configure SWB1 1. VLAN 1: select Switch configuration from Main menu, then VLAN configuration. 2. From the VLAN configuration, select VLAN configuration. Create a VLAN : [ 1 ] Delete a VLAN :[ ] VLAN Name : [ VLAN1] port numbers : U U - U U - Create a VLAN : [ 2 ] Delete a VLAN :[ ] VLAN Name : [ VLAN2] port numbers : U - - U - U U
31 Create a VLAN : [ 3 ] Delete a VLAN :[ ] VLAN Name : [ VLAN3] port numbers : U U - - U - U U U To configure the PVID From the VLAN configuration Menu, select VLAN port configuration port : [ 5] Filter Tagged Frames [ no] Filter Untagged Frames [no] Filter unregistered Frames [no] port name : [trunk1] PVID : [ 3] Similarly configure all the ports as per the PVID for both the switch.
32 2. Configuration of Desktop switches ( 303) SW1 and SW2. In 303/304 switch don t support the multiple VLAN on one port.to connect both the VLANs to the backbone switch one extra ports are configured.select switch SW1 1. From the main menu, select -2 ( System configuration) 2. Select 8 ( port VLA configuration ) 3. Select VLAN1, mark port 1 to 6 4. Select VLAN 2, mark port 7 to 12 Similarly for SW2 configure port 1 to 6 for VLAN1 and port 7 to 12 for VLAN 2. Disable Spanning Tree protocol for all the Switches 3. To configure Multi Link Trunk : 1 From the switch configuration menu, select Multi link Trunk configuration Menu. Trunk Trunk Members STP learning Trunk Mode Trunk Status 1  disabled basic enabled