bcbc Network Technologies

2 NETWORK TRAINING (LAN) Contents l Networks: LAN, WAN l Network Equipment l Transmission l PC Network Settings l Confirmation of Connection

bcbc Network LAN - WAN

4 What is the Network ? Telephone network, TV network l Familiar and well-known network Computer network l Network connects computers and relative devices l One configuration is LAN which is selected according to a system scale and connection. l Internet is one of the networks connecting over the world.

5 What is LAN ? LAN: Local Area Network l It is a computer network in an enclosed zone, for example, a floor in a office, an office, a building, a complex LAN

6 Connection via LAN Star Wiring l The most popular LAN is based on Ethernet using star connection. There are also other kinds of LANs based on other standards. l In this training, we just only explain about the star connection based on Ethernet. LAN

7 Hub Server LAN cable Router To other LAN Connection via LAN Star Wiring l The popular configuration of LAN is the Star connection based on Ethernet. There are also another kinds of LANs based on other standards. l In this training, we only explain about the Star connection based on Ethernet.

8 Ethernet Network Advantages of an Ethernet Network l Ethernet protocol ubiquity l Off-the-shelf functionality l Standardised Hardware, Software & Administration Tools l Built-in routing features & extras u Filtering: converting data formats to match with media u Bridging: connecting LANs u Tree Spanning: construction of a virtual tree structure

9 WAN (1) WAN: Wide Area Network l Well known: the Internet: public network l VPN: Virtual Private Network: using public communication lines (rented lines) Connection to the WAN via DSL (Digital Subscriber Line) l Using analogue or ISDN telephone lines = 1 twisted pair l Transmission rate depends on distance to the next node

10 WAN (2) Unsymmetrical DSLs downstream data rate >> upstream data rate l ADSL (Asynchronous DSL) u good for PC use (high download rate) Symmetrical DSLs downstream data rate = upstream data rate l MDSL (Medium bit rate DSL), HDSL (High..) u connects company’s LANs, video conferences l SDSL (Symmetrical DSL) u multi-media applications l VDSL (Very high bit rate DSL): new

bcbc Network Equipment

12 Network Cable Cable and Connector Type l CAT5 UTP cable with RJ-45 connector are used generally on 10BASE-T/100BASE-TX (Ethernet transmission speeds). u A cross cable is used between equipment or between repeater hubs u a straight cable is used between equipment and switching hub. RJ-45 connectors Network Technology: Equipment

13 Cat5 Cable l CAT5 UTP is an inexpensive unshielded twisted pair data grade cable. l It is similar to telephone cable but the pairs are more tightly twisted. l Other CAT5 cables are the shielded STP or FTP types but u more expensive u allow only short distances between network devices l Maximum UTP CAT5 cable length between devices: 100m (at 100MBps = 100Base-TX) Network Technology: Equipment

14 HUB Different Hubs Hubs connect network devices to each other. So network devices communicate via Hubs. l HUB = Repeater HUB l SWITCH = Switching HUB Network Technology: Equipment

15 l Causing high data traffic because covering all lines Repeater Hub MAC Repeater Hub Transmits Data to All Nodes (Devices) on the Network l Only one transmitter can access the media at a given time l Only Half Duplex mode possible, because data collusion appears when transmitting from more than one device  data drops l All agents must have the same transmission rate (10 or 100 Mb/s) Network Technology: Equipment

16 MAC Ethernet Switch MAC l Transmits data only to the receiver after confirmation of the receiver’s (MAC) address (selected signal path) Switch (Switching Hub) (1) Separate Paths l Independent full duplex paths can exist (simultaneous transmission) l Switches allow a virtual and intelligent routing of Ethernet packets l Agents can have different speeds l Layer-3-switches analyze transmitter’s and receiver’s IP addresses and try to switch all following frames Network Technology: Equipment

17 Switch (2) Spanning Tree (IEEE 802.1D) Switch before auto-configuration Switch after auto-configuration Switch loop in case of failure re-activation l The spanning tree function constructs an internal virtual tree structure between switches to u obtain best network properties u avoid loops u re-activating of de-activated signal paths deactivated Network Technology: Equipment

18 Switch (3) VLAN = Virtual LAN VLAN 1 Switch N-8000MI N-8500 N-8000EX N-8500 N-8000EX VLAN 2 If several applications shall be used in a LAN, then the virtual LAN feature can separate these applications virtually to provide best performance within each VLAN Network Technology: Equipment

19 Switch (4) Unicast/Multicast l Transmission to several receivers u Unicast: sending several of the same data packages to every receiver, i.e. sender must have high transmission rate u Multicast: sending the data packages once but with several destination addresses, and the Switch multiplies it to each receiver Switch Data package with addresses of 3 receivers Network Technology: Equipment

20 Recommendations on Hubs for N-8000 l Repeater hub must not be used  use Switch! u Full duplex operation u Support of spanning tree u Automatic negotiation of transmission speed and mode (IEEE802.3u (100BASE-TX) / IEEE802.3 (10BASE-T) standard) l Multicast is supported by IGMP (Internet Group Management Protocol) l Use QoS (Quality of Service = for real-time audio transmission) equipment as much as possible in a route. l Select VLAN feature when using same LAN for Packet Intercom and PCs l IP stations can be powered by Switches with PoE (power over Ethernet) feature Network Technology: Equipment

21 Networks with Switches Switch N-8000MI N-8500 N-8000EX Switch N-8500N-8000EX Switch N-8000EX N lines because high data traffic expected 2nd line because high traffic expected Network Technology: Equipment

22 Networks with Switches N-8000EX N-8500 Switch N-8500 Switch N-8000EX N-8000MI Switch N-8000EX N-8000MI N-8000EX N-8500 Switch 2nd line is spare line within 100m several N-8000EX Switch in rack several N-8000EX Switch in rack max. 100m high data traffic: 2 lines Network Technology: Equipment

23 Networks with Switches N-8000EX N-8500 Switch N-8500 Switch N-8000EX N-8000MI Switch N-8000EX N-8000MI N-8000EX N-8500 Switch 2nd line is spare line within 100m several N-8000EX Switch in rack several N-8000EX Switch in rack max. 100m high data traffic: 2 lines Network Technology: Equipment

24 Router l A Router connects or divides LANs, it selects the route to transmit data from a subnet into an other subnet. (The routes must be set manually by a network specialist) Subnet B Subnet D Subnet C Subnet A Router Network Technology: Equipment

25 WAN Router l A WAN Router connects LANs to WANs (Wide Area Network), e.g. the Internet LAN WAN e.g. ADSL e.g. Internet or rented line Network Technology: Equipment l Disadvantage of a simple WAN router: it can connect only one device to the WAN

26 Network Technology: Equipment WAN Router with NAT/NAPT General l Shares the Internet connection into several devices l Shares a global IP address for several devices NAT: Network Address Translation l Translates a global IP address into a private IP address l but: only 1 user can access the Internet at a time

27 Network Technology: Equipment WAN Router with NAPT (1) NAPT: Network Address Port Translation l Translates a global IP address and port no. into a private IP address and port no. (IP masquerade) l Several users can access the Internet simultaneously (session; max. no. of sessions!) l Usually it uses a dynamic routing table but this is not suitable for the N-8000 system u N-8000 communicates with acknowledge signals. When using a dynamic routing table, then the acknowledge signal may not be sent back to the correct receiver u Therefore it is necessary to use fixed private port no. which can be set by the N-8000 software

28 WAN Router with NAPT (2) Function of NAPT Router : : : Sender Network Technology: Equipment Receiver Router

29 WAN Router (4) Recommondation for WAN Routers l Use WAN Router with NAPT function Network Technology: Equipment

bcbc Transmission

31 Data Rate (Throughput) Official Data Rate Means the capacity of how many data can be transmitted per second. The data rate is mentioned as bps (bit per second). Sometimes it is called forward speed or line capacity. Effective Data Rate Means the actual capacity of which the data is transmitted. In the LAN, the real transmission rate is 60-80% less. (Besides, around half of the rate in case of half duplex) Network Technology: Transmission

32 Ethernet Protocol Assumes a given transfer media: the standardized Ethernet network Ethernet Packet Structure: Dest.Addr.SourceAddr.PFCSPayload Ethernet LAN Ethernet LAN Protocols Ethernet Protocol vs Internet Protocol Network Technology: Transmission Internet Protocol Makes no assumption on the transfer media Allows transfers across any media & jumps from one media to the other (via bridges) Ethernet LAN Ethernet LAN ATM Ethernet LAN Ethernet LAN

33 IP Address What is an IP Address? l IP address means just the address of the node (device): u An IP address of a LAN (such as in an office) is assigned by a network administrator. u An IP address of the Internet, so called “Global IP Address”, is assigned by an Internet provider Network Technology: Transmission

34 Composition of the IP Address The IP address consists of 4 Bytes, divided into l Host address l Subnet address Example: /24 Example: A slash after the IP address indicates how many bits belong to the subnet address. The remaining bits belong to the host address bits (binary) Bytes written Network Technology: Transmission

35 Example: IP address ” “ but… Subnet mask Network address(Subnet) Host address The above three setting mean: All nodes belong to a different subnet. *Examples /24, /16, /8 Subnet Mask A subnet mask is a parameter that divides the IP address into l the subnet (local network) to which the node belongs to l the host address of the node in the subnet. Network Technology: Transmission

36 Default Gateway Transmitting Data to other Network l When the data shall be transmitted to a node of an other subnet, then it will be forwarded to the node called Gateway in the network. l When the data is not send to a known node in the subnet, then the data is transmitted to the node called Default gateway. l The default gateway (in almost all cases it is a router) can route the data to communicate properly, if the default gateway is set in every nodes. Network Technology: Transmission

37 Browser User Interface l The user interface to display homepages of the (World Wide) Web site l Three features “communication, analysis, display” are provided. u It is used for communication with network devices and display. u In this training, we will explain using the Internet Explorer as the browser. Proxy Network Technology: Transmission

38 User’s computer (Demand) WWW server (Receiver) Proxy server User’s computer (Demand) WWW server (Receiver) Proxy server In case of proxy server is not available. In case of proxy server is available. Network Technology: Transmission

39 Proxy Server Problem l The PC can not communicate with network devices on the LAN if the browser is set in order to connect with the Internet via the proxy server. l Then you have to stop the proxy server using or change the setting of the particular address. Network Technology: Transmission

bcbc Settings

41 Windows2000Windows XP Network setting on PC (1) Select Properties in My Network Places Network Technology: Settings

42 Windows XP Windows2000 Network setting on PC (2) Select Properties in Local Area Connection Network Technology: Settings

43 Network setting on PC (3) Select Properties in Internet Protocol(TCP/IP) Windows2000Windows XP Network Technology: Settings

44 Network setting on PC (4) Change the setting after note the current setting. Windows2000Windows XP Network Technology: Settings

45 Proxy server setting (1) Select Properties of Internet Explorer Click the tag for Connections Network Technology: Settings

46 *Caution Don’t change other topics. Reset after use. Proxy server setting (2) Select the LAN Setting Uncheck after note the number of Address and Port Network Technology: Settings

bcbc Confirmation of Connection

48 Echo requirement Echo response Please respond Hello Confirmation of Connection l Link LED (normal: green) l Ping (confirmation of IP communication) u When a ping is activated on a PC, then the data called echo requirement is transmitted to the other nodes. u When the activation of ping was successful, then it was confirmed that the PC and the node can communicate with IP packets. u The node who received the echo requirement transmits the echo response to the PC Network Technology: Confirmation