Link to home
Start Free TrialLog in
Avatar of archken
archken

asked on

How to achieve full-duplex?

When it comes to Ethernet, I'm not sure what's the difference between half-duplex and full-duplex.  My 100base-TX Fast Ethernet network is based on a switching hub, which shows that I'm often running at half-duplex instead of full-duplex.  Am I missing something?

What should I do to achieve full-duplex?  Is this important?  Is it faster?  Do I have my settings wrong if all I have is half-duplex to and from each computer?  How can I tell the speed difference if this is the case?
ASKER CERTIFIED SOLUTION
Avatar of weed
weed
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of archken
archken

ASKER

Thanks for the link.  However, I do not have any of those three required computers (iMac, B&W G3, Bronze PB).

More specifically, I'm asking if I have the option of improving the half-duplex condition for my current hardware network as follows:  PM9500/G3, PM7200/G3, PB5300c, LC575, HPlaserjet, HPjetdirect plotserver and DSLmodem.  Future addition of another Powerbook at 100base-T speed.

The older PB and LC575 are temporary and may be replaced with new G4's in the future.  All workstations must transfer large CAD and graphic files via TimbuktuPro software.

When does full-duplex "activiate" or become useful in my small network?
You cant improve the half duplex. Its either half duplex or full duplex. There is no middle ground. Since you dont have any hardware that is supported by the duplex extensions then  youre out of luck and you currently have the best you can get. ALL of those computers are 10 Base-T anyway so full or half duplex, its gonna be slow.

The long and short. Until you add computers with 100Base-T you cant do anything about it. Full duplex will never be active on your current network until then.
Avatar of archken

ASKER

But I DO have a 100Base-T card in the PM9500/G3.  The HPlaserjet also has a 10/100 NIC, and the HPjetdirect plotserver is a 10/100 device.  Why do you assume otherwise?

I plan to get the PM7200/G3 a 100Base-T card soon, but the switching hub should keep the others at 100bt speeds, no?

And therefore, are you saying that full duplex should be active now?  But it's not.  The little lights say only half-duplex.  This is my question.

Please do not assume what I did not specify.
The only reason i said full duplex will never be active on your network is that you dont have any machines that will support apples full duplex patchers. Without those patches youre not going to get it. Your card vendors MIGHT have patches to do it but i doubt it. Most devices only do half duplex.


I assume otherwise because you havent informed me otherwise. This is information that should be specified in the question in order to help us answer it. Most people dont install 10/100bt cards in older macs so im going to assume thats the same with you.
Avatar of archken

ASKER

Hmmm.  I'm not sure if I follow your reasoning.  You say, "I assume otherwise because you havent informed me otherwise."  But previously I said, "My 100base-TX Fast Ethernet network is based on a switching hub."  Where did I NOT inform you otherwise?  And how valid is your assumption?

I also hear from you, "Most devices only do half duplex."  But you also said, "Until you add computers with 100Base-T you cant do anything about it. Full duplex will never be active on your current network until then," which implies that if I have 100Base-T, then I should have full duplex.

You've confused me yet again.  Please clarify.
The fact that you have a 10/100b/t switch doesnt mean your computers are using 100bt.

Full duplex does not mean 100bt. There is 10bt Half Duplex, 10bt Full Duplex, 100bt Half Duplex, 100bt Full Duplex. To get FULL duplex on your network you need devices that support it. The devices that support it are Blue and White G3's, 100bt iMacs, G4s and Bronze PBs as well as SOME 3rd party ethernet cards. You havent informed me of the brand of the cards but im sure they shipped with software or documentation that would tell you if they support it. The apple hardware only "supports" it via the apple patches that i pointed you at earlier...which are btw unsupported by apple but they work fine.
Avatar of archken

ASKER

Ah HA!  Getting specific answers from you is almost like pulling teeth.

The key words in your comments are, "FULL duplex... is supported [only by] SOME 3rd party ethernet cards."  You forget to assume the fact that my 10/100 switching hub actually TELLS me whether I'm running 10base half-duplex, 10base full-duplex, 100base half-duplex, and 100base full-duplex.  Yes, all that is shown for each device!

You should know this better than me.

My extrapolation of your words indicate that I'm probably using one of those cheap 10/100 NICs that do NOT support full-duplex.  This would mean I must replace it with more costly 10/100 NICs that DO SUPPORT full-duplex.

I'll be searching for NICs with this very feature to improve my network.  Unless you're still misleading me?
First you scold me for assuming...now youre scolding me for NOT assuming...heh man this isnt helpful.

Yes i know your hub tells you what youre running and youre running at half duplex because you dont have hardware that supports full duplex. (at least not that youve told me about). Thats the long and short of it. If you want to run full you need to find drivers (if available or supported at all) for your ethernet cards, get net ethernet cards, or get new computers. And that only means full will work between computers and devices that BOTH support full.
Avatar of archken

ASKER

Now you're twisting words.  You've missed my point if you don't put all the pieces together.  My point, straight up, is that you first assumed I wasn't running any 100baseT devices (which is incorrect).  But  *if*  you had followed that assumption with another assumption that my switching hub shows the four levels (10half, 10full, 100half, 100full), then from my earlier statement that "I'm running a 100base network," your second assumption would NEGATE your first assumption wouldn't it?  Why would anybody say they're running 100base if they are not staring right at those little lights that say 100base?  Get it?  I'm not "scolding" you for not assuming.  The general point is, Why assume at all?  Just ask me for the information that you need.

Keep in mind that I'm asking my question because I do not know the answer.  If I knew enough to specify that the card does not support full-duplex, or simply that it has  *something*  to do with my card, then I wouldn't be asking my question, would I?  I would be asking a different question.

Only now do I hear you say "to run full you need driver... new cards... new computers... devices that BOTH support full."  What a long way to answer my question!  Did you just look that up at some information web site?

Now you leave me with information that I'm not entirely confident about.  I'm not sure what to do with it.

But thank you anyway.
aye carumba....look...To run full duplex you need to get

1) hardware that supports it

or

2) if your hardware supports it (which i dont know but your manuals will tell you) you need the drivers to enable full duplex

Now as far as all these assumptions are concerned youve GOT to be kidding. Following assumptions with other assumptions and assuming that ive made assumptions and yadda yadda yadda....Ive been saying that to run full duplex you need hardware that supports it from the start. Nothing very difficult about that. I would suggest you buy a basic networking book that covers ethernet LAN topography.