In ATM,cells serve as universal units for all information types:data,voice,video,etc,Since switches know beforehand the size and format of each information unit sent through the network,switch architectures can be 1),Futhermore ,since the CMS determines the connection path during connection setup,switches do not have to make complex routing decisions on a (2) basis.Communiciation paths can be “hard wired” into the switch’s circuits to enable fast,simple decisions. Hardware techniques,using VLSI based state machines and ,in the future,optical switching techniques,can be applied to switches.Hardware Based switch matrices take advantage of all these (3) characteristics.The matrix approach to implementing cell switching greatly increases the scalability of ATM based solutions,One fundamental advantage of matrix based switches is that,as more ports are added to the switching complex,the aggregate switching capacity of the switch increases. In other words, as(4) are added to a switched network, they tap into an increasing band width pool-the complete opposite of shared media networks,where user are forced to share smaller and smaller slices of a fixed amount of (5).Simply put,cell switching based on ATM enables extremely fast,massively scalable networdks. (1) A.optimized B.increased C.decreased D.fixed
9 B+ _" K" _. W, |% ` (2) A.cell by cell B.object oriented C.bit-by-bit D.LAN* r, T; ^. v2 Q/ S2 |
(3) A.VLSI B.OSI C.CMS D.ATM) I* R. r* R, s# C+ ]2 c2 ]
(4) A.cells B.switches C.users D.approaches1 \6 ]. S/ E6 n# o
(5) A.data B.media C.bandwidth D.information
: T0 r0 v3 l* W3 W 答案:1:A,2:A,3:D,4:C,5:C |
发表于 2012-8-2 09:11:00
