When you're studying for your CCNA exam, whether you're attractive the Intro-ICND line or the single-exam path, you're apace introduced to the fact that change occurs at Layer 2 of the OSI model. No difficulty there, but then another cost involving change are tangled in, and whatever of them crapper be more than a lowercase confusing. What is cell switching? What is circuit switching? Most unclear of all, how crapper you hit packet switching? Packets are institute at Layer 3, but change occurs at Layer 2. How crapper packets be switched?
Relax! As you'll wager in this article, the cost aren't that hornlike to ready straight. Packet switching, for example, describes a prescript that divides a communication into packets before they're sent. The packets are then dispatched individually, and haw verify assorted paths to the aforementioned destination. Once the packets come at the test destination, they are reassembled.
Frame change follows the aforementioned process, but at a assorted place of the OSI model. When the prescript runs at Layer 2 kinda than Layer 3, the impact is referred to as inclose switching.
Cell change also does such the aforementioned thing, but as the study implies, the figure in ingest is a radiophone switch. Cell-switched packets are immobile in length. machine is a favourite cell-switching technology.
The impact of journeying change is meet a taste different, in that the impact of environment up the journeying itself is conception of the process. The steer is ordered up between digit parties, accumulation is transmitted, and the steer is then torn down. The circuit-switching profession most old to CCNA candidates is ISDN.
Don't permit these cost tack you. The quaternary assorted cost are describing such the aforementioned process. The important disagreement is that they are occurring at assorted levels of the OSI model, and using a assorted instrumentation method to intend the accumulation where it needs to go.
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