CCNA - Serial questions

Author

Serial questions

jaymaine

2003-11-22, 6:18 pm

Hey everyone, I have a serial question I hope someone can answer... In a network diagram, like the ones in a cisco press book or whatever, when it shows two routers connected together via serial... First, is there anything in the middle of that? I guess that might be a dumb question, lol, but I can't find answers to any of this

And second, what exactly would that represent? Two routers connected from say two different buildings? I guess one of things that confuses me and makes it difficult to understand is that typically the area between two routers that are linked via serial is its own network or subnet... I hope I'm making some sense in my ramblings and sounding too much like a fool

Thanks to anyone that can enlighten me.. I've just found that in my CCNA studies that serial related material just doesn't seem to make it clear to me what's going on

larkspur

2003-11-23, 1:35 am

Jaymaine,
What is between the routers? Well in most casae you'll find that Data Communications link the routers together, frame relay or PTP (point to point). Hope this helps. Also search the internet or cisco for frame relay. that should help clear things up or maybe confuse you a little more. Any way check it out.

dmaftei

2003-11-23, 9:06 am

quote:
Originally posted by jaymaine
First, is there anything in the middle of that?
...
And second, what exactly would that represent?

Yes, there is 'something' in the middle of that. In the simplest case the 'something' is a serial cable. That's a back-to-back configuration: two routers (in the same rack, or maybe on the floor near your desk), and the cable in between.

In a real network the 'something' would be much more complex. If you would follow the path from the first router towards the second one you'd find a serial cable, then a DSU/CSU, then some sort of cable (maybe a phone line), then some sort of switch, then other cables and switches, then a CSU/DSU, then a serial cable and finally your second router.

The point here is that as long as you're interested only in the end-point routers, you couldn't care less about what's in between: the mishmash of cables/switches/DSU/CSUs is logically equivalent to a plain serial cable. That's why in a network diagram you'd see one simple line to represent a serial link.

I hope I made some sense of your ramblings

jaymaine

2003-11-23, 9:48 am

Thanks for the replies.. Yes, that did clear up some confusion

I appreciate it!

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