|
Home > Archive > CCNA > December 2000 > This ISDN diagram is as clear to me as a muddy swamp...
You are viewing an archived Text-only version of the thread.
To view this thread in it's original format and/or if you want to reply to
this thread please [click here]
| Author |
This ISDN diagram is as clear to me as a muddy swamp...
|
|
|
| I should understand this, but I don't! Can someone put me on the path to enlightenment. I simply don't understand the flow of this...
http://unite.com.au/~u4399a/Image1.gif
Can someone give me an idea of how this flows?
Cheers,
Deets
[This message has been edited by Deets512 (edited 12-28-2000).] | |
|
| quote:
Originally posted by Deets512:
I should understand this, but I don't! Can someone put me on the path to enlightenment. I simply don't understand the flow of this...
I am not sure what problem you are having. I will still try start an explanation so you can tell me if I am on the right track.
The time axis is from top to bottom. Each vertical line with a name above it represents a device. The (almost) horisontal lines between devices represents some action happening between those devices. Note that the lines between DCEs are dashed. They represent actions performed inside the telco network. The details are not shown.
Let's start from the top. The router signals the DTE with a signal functionally equivalent to the kind of signal your old fashioned phone sends when you pick up the phone. This causes the DTE to initate a call setup with the DCE. The DCE will ACK to the DCE. At the same time something happends asynchronously on the telco network and sooner or later the called DCE will signal the called DTE.
Was this any help or am I just explaining what you allready knew?
Terje | |
|
| Thanks Terje. Makes sense now. I don't know why, but it just looked like gobbledy-gook to me, until you started talking about async processes, then the penny dropped.
Cheers,
Deets
P.S. Also gave me a chance to work out how to post a pic on this site!! | |
|
| quote:
Originally posted by Deets512:
Thanks Terje. Makes sense now. I don't know why, but it just looked like gobbledy-gook to me, until you started talking about async processes, then the penny dropped.
I am glad I could help. I do appreciate the nice comments people have about my posts even if I do not reply to them. I do not feel like filling the forum with non-technical stuff.
To make this a technical post I include the following random tips:
Before reloading a router that serves as the dial-in node in an ISDN network use the command show ISDN active to see if anybody is dialing into the router right now.
To see more of what happends during dialing try debug isdn q921 or debug isdn q931. Experiment, study and become clever 
quote:
P.S. Also gave me a chance to work out how to post a pic on this site!!
I was impressed!
I wish you the best of luck in your new job!
Terje
| |
|
| If you want to see even more info try the debug ppp negotiation command, it's another good one.
Yankee |
|
|
|
|