communications
Communications services, Full Duplex, Network
What is it that determines whether or not a given network is half or full duplex? Question
Communications services, Full Duplex, Network
What is it that determines whether or not a given network is half or full duplex? 
Subscribe to Alerts! Get questions and answers delivered to your Inbox.
Answer Wiki (Improve, edit or add to this answer)
RATE THIS ANSWER
+2
Click to Vote:
+2
Click to Vote:
- 2
0
Great Question.
Let me see if I can make this very simple. I may get a stern talking to by the networking pros but here is how I keep it straight.
HALF DUPLEX - I like talking on a CB Radio. Only one person can talk at a time. When I send out my voice no one else can send to me. So the traffic is always one way, which over time can be slow.
FULL DUPLEX - Is more like a phone call. You can both talk and hear all of he conversation at the same time. It gives you two way traffic and is faster then HALF.
Sometimes older printer will only run in Half while I think everything out there that is made int he last 5 or so years is FULL.
-------------
What determines whether or not the network is half or full duplex is the equiptment on the network. Is the equiptment supports full duplex then full duplex should be used. If the equiptment only supports half duplex then half duplex should be used.
Browse more Questions and Answers on VoIP and Networking.
Looking for relevant VoIP Whitepapers? Visit the SearchUnifiedCommunications.com Research Library.
Discuss This Answer
You must be logged-in to discuss a question. Log-in/Register
Testy | Jan 31 2008 9:20PM GMT
Thanks for the reply.
Sooooooo, when you say equipment you are saying it is the hardware that determines half or full duplex?
I guess I’m confused because when reading about the EIA-485 interface it states that it is half-duplex. Tell me if I’m wrong but in this case the interface dictates half-duplex? However, I’ve heard that 485 communications can be full duplex with the addition of another twisted pair.
How about Ethernet communications? I’ve heard that legacy Ethernet (10Mb) is half-duplex where 100Mb and 1000Mb are full?
Tbitner | Feb 1 2008 7:14PM GMT
yes, hardware determines duplex not the cable. Legacy 10mb ethernet only supports half duplex, but newer standards can negotiate the duplex. For example a 10mb NIC will only work at half duplex. A 10/100mb NIC will negotiate either half or full duplex, and a 10/100/1000 NIC will also negotiate duplex.
However, a 1000mb ONLY NIC, network port (the specs don’t say 10/100/1000) is full duplex only, it cannot be negotiated.
