Total ISDN Bandwidth??

DirtySouth

I'm wondering if this question were to be asked on the CCNA, what the best answer would be. What is the total bit-rate of an ISDN BRI connection? Is it 144kbps (Effective) or 192kbps (Actual Total)?

2 B Channels - 64kbps - 128kbps
1 D Channel - 16kbps - 16kbps
Overhead - 48kbps - 48kbps
TOTAL: 192 kbps

My teacher explains that the total bit rate would be the correct answer, but it seems like one of those questions that could go either way depending how literal the question is. Thoughts?

Paul Boz

the problem with much of the Cisco material is that it's extremely vague, like this question. Another scenario that bothers me is the ip subnet zero situation. Sometimes it's understood that ip subnet zero is on and some times it's not, and it's frustrating because there should be some degree of consistency with these questions.

DirtySouth

Thanks for the reply, Paul...I totally agree. Anybody else have thoughts on this?

EdTheLad

The total bit rate is 192k,the number of bit actually used is approximately 160k, thats 128 data, 16 signalling and 16 overhead, but these will be transported in a container and effectively use 192k.This question will not appear in the ccna and if it did it would be more specific.Dont let those study guide questions fool you,the questions in the exam are more precise.I dont bother looking at the questions in study guides as they just frustrate me, too many stupid questions that are vague and based to the authors opinion.