Wireless with Full Duplex

Wireless with Full Duplex
according to my CCNP switch book, it says
IEEE802.11 WLANs are always half duplex because transmitting and receiving stations use the same frequency. To achieve full-duplex mode, all transmitting would have to occur on one freqeuncy, and all recieving would occur over a different frequency.
Although thi is certainly possible and practical, the 802.11 stadards do not permit full-duplex operation.
Can anybody explain this "certainly possible and practical " case?

Hi,
I believe that "certainly possible and practical" mean that it would be feasible to send in one frequency and receive in the other achieving full duplex.
This would require a new standard to define devices with 2 frequencies active that would negotiate which one to transmit, and stuff like that.
However, the standards the define the wireless networks were not design for that so they do not allow it.
HTH,
Tiago
If this helps you and/or answers your question please mark the question as "answered" and/or rate it, so other users can easily find it.

Similar Messages

Full Duplex with Mini

I use both my mac mini and black mac book at work. I have been unable to get the mac mini to run at full duplex. I have locked the port on the switch(Cisco3600) but when I force the mini to full duplex it does not connect at all. I have put the mac book on the same port and no problems.As I like to take the mac book with me on the road syncing my files when one system is half duplex is a real problem. Help

Hi,
It might be something specific to the 3600.
I use minis on a 6500 with full duplex set at the switch and set on the Mac and it works great.
Mark

Sound problems, full-duplex not working?

Hi,
Im having a problem with sound, i use ALSA, and when i play a mp3 in XMMS i cant hear the sounds from other apps (as Gaim) until the song finishes and im presented with all of them at once, this means that i get the usual message recieved sound one after the other, until all the messages sent during the song are "heard". and the next song starts.
I think has something to do with full-duplex, but dont know where to look or fix it.
any help?

It doesn't have to do with full-duplex. Full-duplex is being able to play sound out of your sound card and record sound at the same time.
What you want is to be able to play more than one sound at once. Only certain cards and certain drivers support this (one is the emu10k1, the sblive), most don't. If you want to play multiple sounds at once maybe you should install a sound daemon like esd or artsd.

Full Duplex Lost with Wave Files on SB Live! Value (W

Following a clean install upgrade from WinME to WinXP SP2 on a Dell Dimension 400 with an OEM-installed SB Li've! Value (WDM) PCI card onboard, full duplex wave audio (recording one wave file while playing back one or more other wave files) ups and disappears ? ME had it, XP doesn?t. The record side of software mixers I use on the XP OS (Quartz AudioMaster, NCH Swift Sound MixPad/WavePad) fail to acquire or record the wave signal(s) being played back by the mixer side of the application. Stand alone recorders (Roxio Easy Audio Capture, HotKey Sound Recorder) also fail to acquire or record the wave signal(s) being played back by the aforementioned mixers. But if I switch the record input to microphone during the record pass (on those apps that permit such midstream switching), the mic records without incident.
Creative?s Auto Update shows all drivers for the sound card are up to date. Applying Creative?s Knowledge Base Solution ID 645 passes all DXDIAG tests with no problems (text file results available if anyone cares to see them) but the manual test using twin Sound Recorders fails as the second copy (record-designated) Sound Recorder fails to acquire or record a signal from the first copy (playback-designated) Sound Recorder (no error codes display at any time). Clean booting WinXP and running the same record passes doesn?t rectify the problem.
Anyone know what?s going on here? And how to fix it's I?m stumped.
TIA . . .

For benefit of anyone who hits this thread in a search:
FWIW - Following 5-weeks of troubleshooting this problem with Microsoft Tech Support (including a parallel install of the XP SP2 OS), we reached the following conclusion: Since the OEM sound card (Creative Model CT4780) was known to operate in full-duplex mode without incident under my system's prior ME OS but the same card fails to consistently operate in full-duplex mode while running under a virgin parallel install of the XP OS, the source of my full-duplex problem must lie in the files and drivers resident on the XP OS CDROM and dropped to my system by the OS loader/installer. There really isn't any other plausible explanation. Absent its drivers, a sound card's nati've hardware state is either going to be full-duplex or it isn't - it would never be full-duplex sometimes and half-duplex (or simplex) the rest.
The problem was resolved when a retail, nearly identical, sound card (Creative Model SB040) and the drivers and files from its CDROM, were installed on the same system.
Perhaps, somewhere, drivers exist that will permit the CT4780 to operate consistently in full-duplex mode on an XP SP2 OS - but neither Microsoft, nor I, had any success in locating them.

I have an old PowerPC and a Macbook Pro running 10.6.7 sitting side by side. Both are using AirPort to connect to the internet wirelessly to the same router, but the old Mac connects with full bars, but the MBP struggles with only 2. Pls help, thanks!

I have an old PowerPC running 10.4.11 and a Macbook Pro running 10.6.7 sitting side by side. Both are using AirPort to connect to the internet wirelessly to the same wireless router. The old Mac connects with full bars but the MBP struggles with only 2 bars. Pls help, thanks!

BDAqua,
Thanks for the response.
Apple has used the term "Digital Audio" to identify this machine. System Profiler has the following information:
Machine Name: Power Mac G4
Machine Model: PowerMac3,5
CPU Type: PowerPC G4 (2.1)
Number Of CPUs: 1
CPU Speed: 800 MHz
L2 Cache (per CPU): 256 KB
Memory: 768 MB
Bus Speed: 133 MHz
Boot ROM Version: 4.3.3f2
Serial Number: XBxxxxxMK9
Sales Order Number:
Yes, I could connect them by ethernet if all I wanted to do was transfer files, but I would like to network them so I could use wireless internet. The machines are not always so close together, I did that to simplify the testing. With the very slow transfer speeds I am reluctant to move ahead with the internet step.
<Edited By Host>

Full duplex bluetooth with Iphone?

Both my wife and I have a 3G Iphone and our Jabra BT530 headsets seem to not work as full duplex. Is this an issue with Iphone? The Jabra BT530 claims to work in full duplex mode. When I test the system and talk while the other person talks, they can't hear me; it totally cuts out they say. Tried this on two Iphones.

Well, glad to see i am not the only one.
I posted about this issue back in October, and the forum admin removed my post!
I have experimented with this issue many times, and it's always the same result.
If you use your iphone and a BT headset, and the other person is talking, you can't talk over them - because it's only half duplex.
Worse is if you use your iphone with a BT headset and call someone who is driving in their car. The noise from their car occupies the channel, and the only way they can hear you, is if you yell into the headset!
I use my phone for several hours of talktime everyday, and therefore am dependant upon a BT headset (otherwise my arm would fall off).
Because the iphone is essentially un-useable with a headset, I can not use it as a phone!!!
I was praying that Apple would fix the issue with V3.0, but SOL!
I am very surprised that more people do not complain about this. Can we be the only ones to notice the problem? Surely not!

Automatic full duplex not working on Inkjet 1200 with W7

I am using a Business Inkjet 1200dtwn with a clean install upgrade from XP2 to Windows 7 Premium. Automatic Full Duplex worked fine with XP and HP’s driver; but Full Duplex will not work with the Microsoft driver that installed after the upgrade to W7.
Does HP have a driver for my combination? If not, what do you suggest?
Printer was purchased through the HP Store on 11/8/04.
Product model number: C8156A
Product serial number: TH47N11022
Windows upgrade from XP to W7 Premium was purchased through the Microsoft Store earlier this year and is up to date via Microsoft’s automatic upgrade notification.
I bought the HP Pavilion dv9000t Notebook through the HP Store on 12/31/06.
Pavilion dv9000t, p/n: EZ379AV, s/n: CNF7012K4X. aka: HP Pavilion dv9000t CTO Notebook PC.
This question was solved.
View Solution.

Congratulations on your Post! As a Student you earned an A+
Some time ago I got auto duplex to work by deleting the 1200 in Devices and Printers, Restarting just to be safe, then letting Plug-N-Play install the driver by enabling install to search my computer and the web to find the latest driver. The new driver properties had the option to install 2 sided printing. I clicked on the option and tne printer worked (just as you said).
Then I failed to post my solution. My bad
Thanks for your post!

Full duplex with a 100 FX connection

Hello,
I have a WS-2960-24TC-L running with c2960-lanbase-mz.122-40.SE.bin with two GLC-GE-100FX= in it.
I am trying to link this switch to a 3750 with a GLC-GE-100FX= and a WS-2955C-12.
The 2960 always auto negotiate to 100 half with both switches. In the 3750 I can force the port to Full duplex but the DUPLEX command in not ava lable on gig 0/1-2.
I would be nice to have a 100 Full link between the switches.
Can you help me ?

Current GigE is full-duplex only.
You might try using a 10/100 port (as a trunk port if necessary).
You can also try another cable, preferably a commercially made cable in good condition. Poorly terminated hand-made cables, or cables that have been kinked, stretched, crushed {etc} can cause the ports to downshift.
Good Luck
Scott

Not getting full duplex throughput on WRT54GL

So here's the situation. I am on a university network that gives us a 10Mbps HALF duplex connection when using auto-negotiate, so we effectively get a 1Mbps connection. I can manually change the duplex setting on my network card to "full duplex" and then I get a solid 10Mbps connection.
Now I am attempting to use a WRT54GL with this connection. I have configured the router for "full duplex," but whether I am connected through wired or wireless to the router, I consistently get only 1Mbps throughput. Is there any additional setting or hack I can do to force the router to use full duplex with its WAN connection to the campus network?
Thanks in advance!

This option is not available on the linksys firmeware..

Checksumming/Full Duplex on WUSB-G w/SpeedBoost

Hi. I am using a wireless router for internet, and have recently had problems with the 2.01 patch of World of Warcraft. One of the technical suggestions they recommend is setting Checksum Overload to off, and 100x Full Duplex. I do not have either of those settings on my router.
Furthermore, when I try to login into 192.68.1.1, I am prompted for name and password. I leave name blank and enter "admin" (no quotes) for password, but this is not correct. I have never changed the settings of this router.
I believe it has the latest drivers (not sure of specific #)
If anyone can help me adjust the checksum and full duplex options, I would be grateful.
If it is helpful for resolving the greater WoW problem, I can post the description I left on the WoW tech support forums

Checksum Offloading is a hardware function of some high performance network cards - the card does the calculation and inserts the checksum into the packet. This reduces network overhead (CPU Utilization) on the PC.
The USB device does not have this feature.
You did not say what model router you have, but the manual can be downloaded from the www.linksys.com page under support -> Downloads - you need to select your model.
But the short answer is to press and hold the reset botton for at least 10 seconds. This button is located on the back of the router, next to the Internet connection - it is inside a small hole. You need a small pointed object to press on it (a straitened out paperclip works). Then you will need to reconfigure the router as it will be like it just came out of the box...

Travel wireless with n800

Has anyone tried using a travel router with their N800 to connect to a high speed internet connection?.....Thanks

Hi,
I believe that "certainly possible and practical" mean that it would be feasible to send in one frequency and receive in the other achieving full duplex.
This would require a new standard to define devices with 2 frequencies active that would negotiate which one to transmit, and stuff like that.
However, the standards the define the wireless networks were not design for that so they do not allow it.
HTH,
Tiago
If this helps you and/or answers your question please mark the question as "answered" and/or rate it, so other users can easily find it.

Mac Pro 10.6.5 100baseTX Full Duplex Not Working

Hi Guys,
I am having some trouble with the Mac Pros that I support in my office (Early 2009 Model). Our network uses 100baseTX Full Duplex on all of our connections in a mixed PC/Mac environment. This was working perfectly fine until we updated our Mac Pros to 10.6.5 (Went straight from 10.5.6 to 10.6.5).
Every Mac Pro now has itself set to automatically detect the speed, and they keep setting themselves to 100/Half. If I go in and manually adjust it, setting it to 100/Full, I lose all connectivity to the ethernet (it doesn't even recognize that a cable is plugged in). This is causing a lot of troubles for our Mac users trying to access files on our shared drives. It is taking them about 5 minutes to download a 30MB file, rather than the 3 seconds it should.
I tried booting to our portable 10.5.6 drive and 100/Full works just fine. Our PowerMacs on 10.4.11 also work fine on 100/full. I tried using Cocktail and Sudo to force the change, but again the ethernet drops out. The problem persists through all user accounts on all the effected Macs. I have tried a fresh install of 10.6 and the problem persists. If I downgrade back to 10.5 the problem is gone. I know it is not an issue with the network because 2000 other machines are working just fine, and the affected ones work fine when downgraded.
I just spent a good hour on the phone with AppleCare, but after insisting it was a problem with our network for the first 45 minutes, they came to the conclusion that they simply could not help me. According to them, if I want networking help, I need to convince my company to spend $2,800 on their enterprise support, and even then they don't know if they will be able to help me. So, it looks like I am on my own here.
Anyone have any thoughts on what is going on or how to fix it?

Yalp wrote:
The only possibility that I can see is that it is a software problem on these Macs.
There is always a certain level of slack engineering into all these devices. When you start updating one part of a network, you risk exceeding the slack. It is always possible that the problem is with the router hardware or cabling. Certainly, the problem would be with 10.6.5 too. But if you jump to one conclusion or the other without troubleshooting you risk waiting forever for a fix that will never come.
So, what you have to do is connect these Macs to some other router/hub running 100BT/Full (with settings as close to default as possible) with cables that you know are rated at that speed. If that fails, submit a bug report to Apple. If it works, take your router/hub and put it in the network cabinet and connect it to the Mac Pro with the existing cable. If that fails, sue whomever installed the cable and redo it (network people sometimes try to save money with cable). If that works, look at the existing router/hub and see if it has any bugs or firmware updates available. At this point, you could submit a bug to Apple with precise details about your router/hub and also submit one to the manufacturer of the router/hub. Apple will either fix the problem or contact the router/hub manufacturer and get a fix. Once you know precisely what connection is causing the problem, there may be other ways to address it either on the router/hub side or on the Mac side.

B200M3 and Vsphere 5.1 - Unable to set NIC speed to 10gb full duplex

Hi,
My first post here!
I got 4 B200M3 blades with VIC 1240 and 1280. I have installed vSphere 5.1 on them. The blades are configed with a number of NIC's.
The NIC's get a speed of 20gb full duplex(set on auto negotiation) and i would like to set them to 10gb full duplex. When i try to change it in vSphere i get an error message
"Call "HostNetworkSystem.UpdatePhysicalNicLinkSpeed" for object "networkSystem-1264" on vCenter Server "xxxxxxxxxxxxxx" failed.
Operation failed, diagnostics report: Forcing 1000Mbps or faster may not be supported on this network device, please use auto-negotiation instead"
After some searching it looks like you sometimes have to upgrade vSphere with new drivers to get these things to work?
Anyone got any ideas that can help me?
// Fredrik

Hi Fredrik,
A few quick questions:
1) What is the driver type and the version on the vnics? here is the HCL for the required driver versions:
http://www.cisco.com/en/US/docs/unified_computing/ucs/interoperability/matrix/r_hcl_B_rel2.04.pdf
2) Did you install 5.1 direct or did you upgrade from 5.0? For this blade you need to use the CISCO OEM Custom ESXi image. We still do not have the 5.1 image published, however the 5.0 and 5.0 U1 are avaiable for use. Here is the download location:
https://my.vmware.com/group/vmware/details?downloadGroup=CISCO-ESXI-5.0.0-U1-28AUG2012&productId=229
Thanks!
./Abhinav

Can I build a full-duplex serial port?

I want to build a full-duplex serial port with PCI-6533, main features are:
software: LabView
hardware: PCI-6533
serial port: full-duplex,synchronized
clock: 13MHz, external feed
control lines: 3
data: about 1k bytes to be transfered
Thanks and best regards,

You can build it, but it won't be easy. Transmitting should be OK. But, for receiving, you are going to have to parse the information out of your incoming bitstream to get the information from the frame.
Also, there is a peculiarity when usng the 2 timing sections together on the 6533. If you use any data width greater than 8 bits, you are only going to get 10MHz on each 'side', since the data has to be split between them by word. However, since you are serial and only using one bit, you don't have to worry.

Half duplex or full duplex configuration for MDS9124 management port?

Hi All,
Is it possible to set the management port of mds 9124 about half or full duplex configuration?
I want to correct following error:
Jun 13 10:27:20.799 GMT: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on GigabitEthernet4/18 (not half duplex), with mtw1pc02bs0(FOX1450G8QG) mgmt0 (half duplex).
it seems mds 9124 set his port to half duplex.
Dennis

You may want to check this thread :
https://supportforums.cisco.com/thread/2059109
Else try the following :
switch# config terminal
switch(config)#
switch(config)# interface mgmt0
switch(config-if)# switchport duplex full
switch(config)# exit
switch#
switch# copy running-config startup-config
Also, I would suggest you check what the counterpart of your MDS switch mgmt interface is set to (i.e. is it set to autoneg, then try setting it to fix speed/duplex or the other way around).

Wireless with Full Duplex

Similar Messages

Maybe you are looking for