Hi there,
This is my first post on this group, but I've been following it for a while and find it very helpful. I am a CCNA student and was just having a bit of a problem trying to understand some concepts of serial interfaces.
First of all, I was wondering about speed. In most situations, the Cisco curriculum uses serial interfaces to interconnect routers. But let's say you have a network of 100 computers behind a router and they are trying to get to the internet through that serial interface. I can't help but notice that the 2 mbps or so is painfully slow for a network of that size. I've come across an interface known as High Speed Serial Interface, which solves that problem by introducing a 52 Mbps bandwidth. But on the downside, maximum length for that cable is
50 feet.Which brings me to my second point of confusion. If the diagrams interconnect regional office with Headquarters, one would expect exceptional lengths (miles and miles), but any kind of serial interface has a very limited length (usually 10 feet). So how can this diagram possibly be true? As far as I am aware, only Fiber optic allows you these lengths, but for a smaller company this is extremely expensive.
Would anyone be able to clear that up for me? Thanks in advance