Thank you Professor!! You’ve been helping me along my Comptia journey by explaining these topics in basic English! The way Comptia words things in their lessons is like reading a law book without knowing the dictation. Deciphering the text and trying to learn these concepts simultaneously makes it challenging to learn by myself. Maybe I’m just an illiterate fool lol formal English is definitely not my forte!
5:35 When he says "Half-duplex goes 400meters while full-duplex goes 2kilometers" is half-duplex just mean single mode fiber and full duplex is Multimode fiber? from my understanding, Half-Duplex allows communication in both directions but not simultaneously. & Full-Duplex mode enables bidirectional communication.
nvm, I think I got it: Full Duplex: Talk and listen simultaneously. (you'd use two strands for full duplex in single-mode fiber(Because 1 strand is for sending, other 1 is for receiving), Unless your using WDM(Which lets data travel both ways by using different wavelengths, even on a single-mode fiber strand) Half Duplex: Take turns to talk and listen. (rare in fiber, common in WIFI 5 & below, & in old Ethernet devices like hubs) Simplex: Just one way. Like a megaphone, all talk, no listen.
Commenting here means we're already in the process of watching a video that's less than 10 minutes long so we might as well watch it and remember as much as we can
I'm kind of confused about single mode and multimode, duplex, and BiDi. So single mode and multimode can both be either full, half, or simple duplex? And is BiDi just another way to say half duplex, or is BiDi full duplex over 1 strand? or is that something different? And is the WDM thing a standard or so for half duplex?
With half-duplex, the length has to be limited so both sides can detect a collision when transmitting. If the distance is too long, a collision could occur after a device has completed their transmission so a backoff and retry would not be an option.
What is the reason that for CAT8 the increase of bandwidth is just times 4 and not 10? Does that have any correlation with usb-c thunderbold 3 also having 40gb/s?
Category 8 cable doesn't have a speed; it's just a cable. The standard of Ethernet is the 40GBASE-T standard, and it operates at 40 gigabits per second. The minimum cable required to run this standard is one constructed to the tolerances of the Category 8 specification.
at 2:17 it says 100BASE-TX uses 2 pair cable. Yet it also says Cat 5 is the minimum cable requirement. Cat 5 uses the normal 4 pair contact. So if cat 5 is the minimum then wouldn't it be 4 pairs of cable? Also, another note, I think you should just put Cat 5e on the 1000BASE-T slide because Cat5 does not officially support 1gbps speeds on modern devices so it is a little confusing. Thank you for your videos!
The category of cable defines the physical characteristics of the cable, and the category type is not related to how many individual wires will be used by a particular network type. The IEEE 802.3 standard for 1000BASE-T sets the minimum cable type for the standard as Category 5.
@@professormesser ah okay. so even though the minimum requirement for 100BASE-TX is Cat 5, which has 4 pairs in it, the 100BASE-TX only uses 2 of those 4 pairs. Also, I understand your reasoning on the latter point as well. I have now been sent down a rabbit hole of what speeds and distances are actually possible over different Categories of cable and Bit Error Rate and stuff. Very interesting stuff. Thanks again for going out of your way to help others. I'm hoping to pass this exam soon 🤞
If I understand correctly, will ISP use a WDM Multiplexer and WDM Demultiplexer on a VPLS circuit? Since multiple companies get hosted on the same Fiber Link? Just trying to see if I understand the concept and see how it would be implemented in a real-world scenario. Thanks!
40 GIG a SECOND is INSANE
I stand corrected 1.6 tbits is insane
divide it by 8 and you get 200 gigabytes per second. This is madness o_o
is it just me or are these videos amazing? thanks a lot for uploading
These videos are amazing but maybe you are too!
Thank you Professor!! You’ve been helping me along my Comptia journey by explaining these topics in basic English! The way Comptia words things in their lessons is like reading a law book without knowing the dictation. Deciphering the text and trying to learn these concepts simultaneously makes it challenging to learn by myself. Maybe I’m just an illiterate fool lol formal English is definitely not my forte!
Most interesting unit so far
That's what she said!! 😳
2 days left after 3 months of studies every day. 2 books and multiple sources
did you pass
@@hardtailfails Did you survive the exam?
@@elnomade268 no wasn't able to pass it in not good at tests
I am about to go test right now and I dont feel confident.@hardtailfails
@@familyquinn1684 did you pay for the back up test voucher thing whatever they call it
5:35 When he says "Half-duplex goes 400meters while full-duplex goes 2kilometers" is half-duplex just mean single mode fiber and full duplex is Multimode fiber?
from my understanding, Half-Duplex allows communication in both directions but not simultaneously. & Full-Duplex mode enables bidirectional communication.
nvm, I think I got it:
Full Duplex: Talk and listen simultaneously. (you'd use two strands for full duplex in single-mode fiber(Because 1 strand is for sending, other 1 is for receiving), Unless your using WDM(Which lets data travel both ways by using different wavelengths, even on a single-mode fiber strand)
Half Duplex: Take turns to talk and listen. (rare in fiber, common in WIFI 5 & below, & in old Ethernet devices like hubs)
Simplex: Just one way. Like a megaphone, all talk, no listen.
Thankyou professor you helped thankyou. God bless thankyou.
Thank you!
You are amazing
Awesome video as usual
How important would you say memorizing ethernet standards would be toward the exam?
They are all testable questions, so all of them.
Look at the exam objectives and the way each knowledge section is weighted in the test. It’ll tell you exactly how many points you will gain or lose.
Man no way I’m gonna remember all of them 😂
@@froot3839 you can just understand them know and memories them before the exam
Commenting here means we're already in the process of watching a video that's less than 10 minutes long so we might as well watch it and remember as much as we can
I'm kind of confused about single mode and multimode, duplex, and BiDi. So single mode and multimode can both be either full, half, or simple duplex? And is BiDi just another way to say half duplex, or is BiDi full duplex over 1 strand? or is that something different? And is the WDM thing a standard or so for half duplex?
I'm thinking about that 1.6Tb/s connection. Like, GTA5 would install in a matter of seconds on Steam
The fastest m.2 SSDs you can buy have read/write speeds of 7300 MB/s so that's what the speed would be for downloading not 1.6 Tb/s.
You are thinking far to small. You could download the entire PlayStation 2 library in less than a minute!!!
How is multi-mode fiber associated with laser? I'm confused. Shouldn't it be single mode for laser and multi mode for light?
Although it's common to see laser used with single mode fiber, there are some Ethernet standards that use laser light over multimode fiber.
@@professormesser Thank you Professor :)
How come with fiber, half-duplex has a shorter length span than full-duplex? I would've thought it would be the other way around.
With half-duplex, the length has to be limited so both sides can detect a collision when transmitting. If the distance is too long, a collision could occur after a device has completed their transmission so a backoff and retry would not be an option.
@@professormesser Ooh ok, thank you very much!
What is the reason that for CAT8 the increase of bandwidth is just times 4 and not 10? Does that have any correlation with usb-c thunderbold 3 also having 40gb/s?
Category 8 cable doesn't have a speed; it's just a cable. The standard of Ethernet is the 40GBASE-T standard, and it operates at 40 gigabits per second. The minimum cable required to run this standard is one constructed to the tolerances of the Category 8 specification.
@@Distress. that's probably what people thought when 1000BASE-T was released
at 2:17 it says 100BASE-TX uses 2 pair cable. Yet it also says Cat 5 is the minimum cable requirement. Cat 5 uses the normal 4 pair contact. So if cat 5 is the minimum then wouldn't it be 4 pairs of cable?
Also, another note, I think you should just put Cat 5e on the 1000BASE-T slide because Cat5 does not officially support 1gbps speeds on modern devices so it is a little confusing.
Thank you for your videos!
The category of cable defines the physical characteristics of the cable, and the category type is not related to how many individual wires will be used by a particular network type.
The IEEE 802.3 standard for 1000BASE-T sets the minimum cable type for the standard as Category 5.
@@professormesser ah okay. so even though the minimum requirement for 100BASE-TX is Cat 5, which has 4 pairs in it, the 100BASE-TX only uses 2 of those 4 pairs.
Also, I understand your reasoning on the latter point as well. I have now been sent down a rabbit hole of what speeds and distances are actually possible over different Categories of cable and Bit Error Rate and stuff. Very interesting stuff.
Thanks again for going out of your way to help others. I'm hoping to pass this exam soon 🤞
If I understand correctly, will ISP use a WDM Multiplexer and WDM Demultiplexer on a VPLS circuit? Since multiple companies get hosted on the same Fiber Link? Just trying to see if I understand the concept and see how it would be implemented in a real-world scenario. Thanks!
A company would normally be backed up by a secondary ISP circuit as a fail-over.
What type of cables does big companies use to provide internet to home, office, etc?
I believe you are referencing coaxil cable- sometimes fiber
🥲