Part - ISwitches: Anetworkswitchis asmall hardware devicethat joins multiplecomputers together withinone local area network (LAN). Switches are incapable of joining multiple networks or sharingan Internet connection. Ahomenetworkwithaswitchmust designateonecomputer as thegatewa to the Internet! and that device must possess two network adapters for sharing! one forthe home LAN and one for the Internet "AN. "ith a router! all home computers connect to therouter e#uall! and it performs the e#uivalent gatewa functionsNowadas switches are used b most business to connect computers! printers and servers withina building or campus. A switch serves as a controller! enabling networked devices to talk to eachother efficientl. Switches can save business mone and increase emploee productivit thoughinformation sharing and resource allocation. Advantages of Network Switches$here are some advantages of network switch such as it handles network traffic successfull!while making efficient use of the available network bandwidth. Packet Handling of Network Switches: $he abilit to route packages to designated endlocations is one of the ke advantages to using network switches. $his is a great leapforward from hubs! which are onl able to send packages without specification from one%device to all other devices attached to their network. $his abilit to designate specific endlocations prevents &thernet collisions from occurring. Collision Management of Network Switches: "hen two computing devices attempt totransmit information at the same time! then collision generall occurs. $his in turn causesthe signals to collide on the wire. $he devices should tr to retransmit the data later on. Ingeneral! the collision will increase depending on the number of the devices on a network. Network switches eliminate collisions b creating a direct on'the'fl connection betweenthe sending and receiving devices or computers. $his improves performance andefficienc across the network! allowing for complete bandwidth availabilit. Bandwidth Utilization of Network Switches:Network switches allow for theavailabilit of the full gigabit of bandwidth for each connection. $his means that networkperformance remains unaffected bmultiple devices working on the same switch.Network switches are therefore able to send and receive data at the same time! unlikehubs. Problem Isolation of Network Switches: &ach device operates on its own wire within anetwork switch. $his makes it easier to pinpoint the area of concern if a problem arises ona given switch port. It also allows other devices to continue to function normall withoutdisruption. Transarent:Switches learnthelocationof thedevices that theareconnectedtoinstantl. $he net result is the most network traffic onl goes where it needs to rather thanto ever port. (n bus networks! this can make the network significantl faster. C!t"thro!gh architect!re: $he data frame begins to e)it the switch almost as soon as itbegins to enter the switch. Disadvantages of Network Switches$here are also some disadvantages of network switches. Such as*+ Sometimes fault frames are forwarded in cut'through architecture. Network switches tend to be difficult to install and use. $he often re#uire e)tensive training to repair if the network goes down. In addition! configuration is necessar when handling multicast packets! which can becomplicated. ,uersshouldtakee)traprecautionswhenrunningswitchesinmodesthat leavethenetwork susceptible to securit risks. $hese risks include spoofing of I- address and thecapturing of &thernet .rames.Reasons behind buying and using a switch: /heaper than a router. 0sers can still connect the switch to a router. 1ultiple switches can use the same router. 2uicker than routers for internal communication. Less latenc at LAN. ,ut man routes have an &thernet switch built inRouters: A router is a networking device that forwards data packets between computer networks. 3outers perform the 4traffic directing4 functions on the Internet. A router is connected to two or more data lines from different networks (as opposed to a network switch! which connects data lines from one single network). "hen a data packet comes in on one of the lines! the router reads the address information in the packet to determine its ultimate destination. $hen! using information in its routing table or routing polic! it directs the packet to the ne)t network on its journe. Historical and technical information: $he ver first device that had fundamentall the same functionalit as a router does toda was the Interface 1essage -rocessor(I1-). I1-s were the devices that made up the A3-AN&$! the first packet network. $he idea for5a router (called 4gatewas4 at the time) initiall came about through an international group of computer networking researchers called the International Network "orking 6roup (IN"6). Set up in %78+ as an informal group to consider the technical issues involved in connecting different networks! later that ear it became a subcommittee of the International .ederation for Information -rocessing. $hese devices were different from most previous packet networks in twowas. .irst! the connected dissimilar kinds of networks! such as serial lines and local area networks. Second! the were connectionless devices! which had no role in assuring that traffic was delivered reliabl! leaving that entirel to the hosts. $he idea was e)plored in more detail! with the intention to produce a prototpe sstem! as part of two contemporaneous programs. (newas the initial 9A3-A'initiated program! which created the $/-:I- architecture in use toda. $he other was a program at ;ero) -A3/ to e)plore new networking technologies! which produced the -A3/ 0niversal -acket sstem< due to corporate intellectual propert concerns it received little attention outside ;ero) for ears. Sometime after earl %78= the first ;ero) routers became operational. $he first true I- router was developed b >irginia Stra?isar at ,,N! as part of that 9A3-A'initiated effort! during %78@'%78A. , the end of %78A! three -9-'%%'based routers were in service in the e)perimental prototpe Internet. $he first multiprotocol routers were independentl created b staff researchers at 1I$ and Stanford in %7B%! the Stanford router was done b "illiam Ceager! and the 1I$ one b Noel /hiappa! both were also based on -9-'%%s. >irtuall all networking now uses $/-:I-. .rom the mid'%78Ds and in the %7BDs! general'purpose mini'computers served as routers. 1odern high'speed routers are highl speciali?ed computers with e)tra hardware added to speed both common routing functions.T#es of $o!ters"Broadband $o!ters: ,roadband routers can be used to connect computers or to connect to the Internet. If ou connect to the internet through phone and using =>oice over I- technolog (>(I-) then ou need broadband router. $hese are often a special tpe of modem (A9SL) that will have both &thernet and phone jacks.%ireless $o!ters: "ireless routers create a wireless signal in our home or office. So! an -/ within range of "ireless routers can connect it and use our Internet. &dge $o!ter: $his tpe of router are placed at the edge of the IS- network. $he are normall configured to e)ternal protocol like ,6- (,order gatewa protocol) to another ,6- of other IS- or large organi?ation.S!bscriber &dge $o!ter: $his tpe of router belongs to an end user (enterprise) organi?ation. ItEs configured to broadcast e)ternal ,6- to itEs providerEs AS(s).Inter"ro'ider Border $o!ter: $his tpe of router is for Interconnecting IS-s! this is a ,6- speaking router that maintains ,6- sessions with other ,6- speaking routers in other providers ASEs.Core $o!ter: A router that resides within the middle or backbone of the LAN network rather than at its peripher. In some instances! a core router provides a step'down backbone! interconnecting the distribution routers from multiple building of a campus (LAN)! or Large enterprise Location ("AN). $he tend to be optimi?ed for a high bandwidth. %ired and %ireless $o!ters: Fome and small office networking is becoming popular da b da b the use of I- wired and wireless router. "ired and wireless router are able to maintain routing and configuration information in their routing table.$he also provide the service of filtering traffic of incoming and outgoing packets based on I- addresses. Some wireless routers combines the functions of router with those of a network switch and that of a firewall in one.@Things we sho!ld consider before b!#ing a $o!ter: "e live and work in an untethered world! and our home or our small business is no different. "hen ou initiall built our network! ou ma not have seen the need for wireless. Now that our compan has grown and our workforce has become more mobile! ou ma be considering adding wireless to our network. "ireless offers a lot of benefits! such as allowing our emploees to work from anwhere and providing Internet access to visiting guests. If ouEve been looking at adding wireless connectivit to our companEs network! ou know it can be confusing. $hereEs the alphabet soup of standardsGHb!I Hg!I HnIG and terms like Hdual'band!I Hselectable!I and Htwo radio.I"hen looking for a wireless router! ou first want to check whether itEs Hb!I Hg!I or Hn.I $he letters refer to the wireless communication standard on which the router is based* BD+.%%b! BD+.%%g! and BD+.%%n. $he first generation of wireless routers was Hb!I followed b Hg!I and nowHnIGthe newest generation. $he primar difference among the router standards is speed (more on that in a bit) and range. Cou wonEt find man HbI routers available anmore (e)cept on e,a! perhaps) because itEs old technolog.Single and (!al: "ireless communications operate in two bandsG+.=6F? and @6F?. 3outers based on BD+.%%b and BD+.%%g standardsGand some HnI routersGuse the +.=6F? band< however! the BD+.%%n standard allows wireless devices to use the @6F? or +.=6F? band. 3outersthat operate onl in the +.=6F? band are referred to as Hsingle bandI. "ireless HnI dual'band routers are also available as HselectableI or HsimultaneousI models! sometimes referred to as Hsingle radioI or Htwo radio!I respectivel. A selectable wireless HnI router! can operate in either +.=6F? or @6F? mode< a simultaneous HnI device can operate in both fre#uencies at the same time. In "i'.i wireless networking! dual band is the capabilit to transmit on the @ 6F? band of BD+.%%a and also the +.= 6F? band used b BD+.%%b! BD+.%%g! and BD+.%%n. 9ual'band routers Acontain two different tpes of wireless radios that can support connections on both +.= 6F? and @ 6F?. $he @6F? band provides better performance and coverage due to less interference.Seed: "ireless router performance varies b standard with BD+.%%b providing the slowest speeds at up to %%1bps. "ireless HgI routers deliver a ma)imum speed of @=1bps while devicesbased on the BD+.%%n standard are fastest! topping out at 5DD1bps.Sec!rit#: 1ost routers currentl support standard "&- securities as well as the more secure "-A and "-A+. If ou want to control what users can access when the are connected to the router! ou want to have one that offers decent Access /ontrols. /iscoEs 3> Series 3outers have ver effective Access /ontrol settings and controls that allow limiting internet use based on time of da. 6uest Access and an abilit to create multiple SSI9s are also important securit measuresif ou are using the router for a small business. $ogether! these two features allow ou to segment our network into separate areas for guests and trusted users.8