ISDN on CCNA

homerj742

Is this a topic that is prominent on the CCNA exams? I know it's slowly being phased out, and to me it requires quite a bit of study. Is it worth knowing all the ins & outs FOR the exam?

Danman32

Yes, be familiar with it. You should see some patterns to Cisco implementations of other WAN technologies, which will help your studies. Dialup is still used as a backup to faster WAN accesses, and sometimes ISDN is used as a backup as well, though because of its cost and infrequent use, PSTN dialup is more likely to be used now than ISDN.

xanderuk2

Yes, I agree with Danman. Be familiar with the theory behind ISDN, it's uses and common commands.

I had several questions on ISDN during my exam that covered the basics.
Know your reference points R,S,T,U etc and the terms such as TA, TE1 & 2 etc.

BRI for sure, PRI not so much (if any). In truth I never really studied PRI in any great depth

homerj742

Great thank you for the help and I will be sure to be familiar with the fundamentals.

DaveX4285

I just took the ICND 640-811 exam yesterday and honestly there was very little ISDN material. I would make sure you are familar with the technology and some basic commands, but I wouldnt get into much detail. My biggest piece of advice would make sure you can subnet quickly and can implement vlsm.

homerj742

I didn't know there would be any implementation on VLSM?!

Danman32

VLSM is basic on the exam. It should be obvious, though you might have to think about it for a moment. Stuff like using /30 addresses for point-point WAN links, enough addresses for another block of hosts on another subnet, or even perhaps a block of addresses on the other side of the WAN. If you have any programming experience, think of it as carving memory allocation for programs, data, and the like.

I heard they were going to begin phasing out ISDN, and there may not be many questions on it, but the passing score is 849, so missing too many 'occasional' questions could fail you.

If all the questions were evenly scored, each question is worth about 20 points. Figure that means you can get no more than 7 questions wrong.
(it is about 50 questions on the test, right? I forget)

ciscos

in my opinion isdn the most difficult lab in ccna...
It demands huge configuration(in comparison to all the others topics in ccna)