[SOLVED] Need help understanding this question

[ThatsAJokeK]

Which of the following speeds would a wireless network perform at when the network is built in bridge mode containing 802.11g , 802.11n and 802.11ac

A.11 Mbps
B.54 Mbps
C.450Mbps
D.1300Mbps

The correct answer was D Im just not sure how to come up with this by myself

 

[DeauteratedDog]

1300 Mbps is the fastest rate for 802.11ac with a 80 MHz wide channel, short guard interval, and 3-spatial streams.

There really isn't enough information to answer the question, since they don't specify the channel width or the number of streams, or the guard interval. You can reasonably assume short guard interval and 80 MHz, but the number of spatial streams is a key differentiator in any MIMO supporting wi-fi gear.

Here is a link to the secret decoder ring for 802.11n/ac/ax data rates.

MCS Index, Modulation and Coding Index 11n and 11ac

802.11n & 802.11ac MCS Index

mcsindex.com

 

[kanewolf]

Which of the following speeds would a wireless network perform at when the network is built in bridge mode containing 802.11g , 802.11n and 802.11ac

A.11 Mbps
B.54 Mbps
C.450Mbps
D.1300Mbps

The correct answer was D Im just not sure how to come up with this by myself

First thing -- 11g, 11n DON'T guarantee a 5Ghz band. BUT 11ac guarantees a 5Ghz band. Then you can look up data rates for 5Ghz 11ac.

 

[bill001g]

Your problem is there is not enough detail to actually get a correct answer. It leaves a lot to assumption.

I am betting there are assuming 2 identical units talking to each other. They would then negotiate the highest rate they will both accept.

802.11ac runs at many many speeds. They do not say which radio band the devices support either. If it were to connect on 2.4g then 450 would the correct answer. Who every wrote the question must not know that all the 802.11n encodings are fully incorporated in 802.11ac.

It would be extremely uncommon to run 2 units in bridge mode running 3x3 mimo. This type of application would be point to point wireless directional outdoor bridges. Because of it being directional you can only really get 2x2 to work maximum.

Question is missing way too many details to actually give a valid answer.

 

[DeauteratedDog]

Please tell me that this isn't something from the CWNP guys, they are usually so much better than this.

(CWNP) Certified Wireless Network Professional Certification | Wireless Certification Program and Training

CWNP (Certified Wireless Network Professional) is dedicated to delivering the knowledge, learning tools and resources needed to achieve enduring success in IT and wireless networking training.

www.cwnp.com

 

[ThatsAJokeK]

Please tell me that this isn't something from the CWNP guys, they are usually so much better than this.

(CWNP) Certified Wireless Network Professional Certification | Wireless Certification Program and Training

CWNP (Certified Wireless Network Professional) is dedicated to delivering the knowledge, learning tools and resources needed to achieve enduring success in IT and wireless networking training.

www.cwnp.com

No just a random quiz I found on the internet for practicing A+1001 cert

 

[ThatsAJokeK]

No just a random quiz I found on the internet for practicing A+1001 cert

Please tell me that this isn't something from the CWNP guys, they are usually so much better than this.

(CWNP) Certified Wireless Network Professional Certification | Wireless Certification Program and Training

CWNP (Certified Wireless Network Professional) is dedicated to delivering the knowledge, learning tools and resources needed to achieve enduring success in IT and wireless networking training.

www.cwnp.com

Update took my Comptia A+ 1001 and this exact question was on it same wording

 

[bill001g]

Shows the value of comptia

It is such a easy cert to get it has very little value. You have so many people with multiple cisco certs wanting the same jobs. It is good as a study guideline if used correctly. Way too many people just brute force memorize all the questions and answers since even the cisco certs have all the questions leaked. So many people I interviewed had great test scores but had to clue how things really worked.

 

[hang-the-9]

cert to get it has very little value. You have so many people with multiple cisco certs wanting the same jobs. It is good as a study guideline if used correctly. Way too many people just brute force memorize all the questions and answers since even the cisco certs have all the questions leaked. So many people I interviewed had great test scores but

I took a few of the tests, and I think I would have gotten near 100% correct on one but the answers they provided were only partially correct with the details they gave. There could be several correct answers, and at times the best solution was not there. I read over the test later and some of the questions I had to shake my head at because I actually did those same things at a real live job and did it the way the answer I chose was done yet they were marked as wrong.

I also had a test given for a job interview that had the same issue with not enough information given for a good answer, I had to tell the person asking the questions that some of them were incorrect the way they were asked when they said I was wrong, the answer they said was correct was only correct if a different question was asked. Although that may have been part of the test LOL