Go Premium for a chance to win a PS4. Enter to Win

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 4858
  • Last Modified:

Difference between Half-duplex and Full-duplex throughput

Hi,

This may be a simple networking question but no one I've asked seems to have a concrete answer. My question is what is the difference in throughput between a half and a full duplex connection, i.e. if I have a 10Mb connection am I really getting 5Mb in a half-duplex, is one slower than the other or is this comparing apples and oranges? Thanks.
0
cuba_joe
Asked:
cuba_joe
1 Solution
 
Pete LongConsultantCommented:
Thin of data like a voice conversation............

half duplex is like CB Radio data can only go in one direction at any time

full duplex is like telephone, data can go in both directions at once
0
 
Gareth GudgerCommented:
No you can get 10MB in half duplex.

10MB is the speed or bandwidth of the connection.

Duplex mere means whether of not you can send and listen. Or send and receive at the same time.

Full Duplex - send and receive at the same time (like using a phone)
Half Duplex - only one can send at a time (like a CB radio)
0
 
Gareth GudgerCommented:
Wow...Pete we posted at the same time and gave the same gosh darn analogy.....seems like us old folk are partial to out CB radios :)
0
What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

 
Pete LongConsultantCommented:
ROFL - its the best analogy there is, and the one I always use when the question comes up :)
0
 
Gareth GudgerCommented:
Aye, that be right.

Now for some reason I am thinking of that evil trucker movie and the traumatic CB chatter....."Candy cane...where's my caaaandy-caane."
0
 
Pete LongConsultantCommented:
:) Yeah I've seen that one :)
0
 
Gareth GudgerCommented:
Dont mind us cuba_joe, we are just overtaking your thread talking about CB radios, truckers and horror movies.

LOL...

Did that answer your question?
0
 
lrmooreCommented:
I like to show the math.
On a half-duplex connection, because of the inevitable collisions and the collision detect/avoidance mechanisms built into Ethernet, the maximum practical bandwidth consumption is ~ 60% of the total bandwidth. This is, of course, dependent on the total number of users sharing that 10Mb.
For example, if you have 10 hosts all connected to a 10Mb HUB (all half-duplex), then all 10 users only get a portion of the 10Mb, reduced down to effective 6Mb, or .6Mb per host.
If that 10Mb HUB was replaced by a 10Mb SWITCH where each port is full-duplex, then you would have full, dedicated, 10Mb to each and every host. And, since it is full-duplex, you can send 10Mb and receive 10Mb at the same time, therfore your throughput is now 20Mb.
So the difference between half-duplex @ .6Mb and full-duplex @ 20Mb throughput is significant.

0
 
cuba_joeAuthor Commented:
Thanks lrmoore. Although the answers above were good, I know the difference in concepts between half and full duplex, but you provided the practical aspect of how the network traffic is adversely affected, which is exactly what I was looking for. Thanks again.
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now