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TICKET ARCHIVE -> Half or full duplex in Network/Ethernet settings?
RobinS - May 11, 2006 - 11:33 am
System Preferences > Network > Show Built-in Ethernet > Ethernet > Duplex >
Should this be half or full duplex. And why?
I'd love to improve my lousy VOIP handoff and noticed this set to half duplex.
Should this be half or full duplex. And why?
I'd love to improve my lousy VOIP handoff and noticed this set to half duplex.
mookie - May 11, 2006 - 12:01 pm
Good day,
My name is Alex and I will try to asist you.
First a question, is there a specific rason that the ethernet configuration is set to "Manually"? I believe that by default this starts with a setting of "Automatically".
In my bisuness network I have been forced to use manually and force 100baseTX and full duplex because the switch I connect to doesn't respond appropriately to queries from the Mac and I end up with a half duplex setting.
Half duplex will only allow communication in one direction at a time. Like a walkie-talkie. If I try an FTP on my network running half duplex it will take 5X (at a minimum) longer than if I can use full duplex.
Not being sure of the type of connection we are adressing here, try this. Change the ethernet settings to 100baseTX and the duplex to full-duplex and let us know if that works.
regards,
Alex
My name is Alex and I will try to asist you.
First a question, is there a specific rason that the ethernet configuration is set to "Manually"? I believe that by default this starts with a setting of "Automatically".
In my bisuness network I have been forced to use manually and force 100baseTX and full duplex because the switch I connect to doesn't respond appropriately to queries from the Mac and I end up with a half duplex setting.
Half duplex will only allow communication in one direction at a time. Like a walkie-talkie. If I try an FTP on my network running half duplex it will take 5X (at a minimum) longer than if I can use full duplex.
Not being sure of the type of connection we are adressing here, try this. Change the ethernet settings to 100baseTX and the duplex to full-duplex and let us know if that works.
regards,
Alex
RobinS - May 12, 2006 - 12:27 pm
Upload speed is identical.
Download speed is identical or a little slower.
Any other suggestions? And should I just leave it in full duplex? Why would one pick half duplex?
Download speed is identical or a little slower.
Any other suggestions? And should I just leave it in full duplex? Why would one pick half duplex?
mookie - May 12, 2006 - 12:59 pm
Hello again,
I need to ask a few questions to proceed:
1) were the network settings manually changed from their "automatically" default to "manually" with half-duplex and if so why
2) what type of network are we addressing? is it a single Mac plugged directly into a DSL or Cable modem? Is it dial-up? Are you plugged into a hub or a switch and if so how does the network access the Internet (through DSL, etc.)
3) are you attempting VOIP within your network or out through your connection to the Internet?
If we understand your network topology a bit better it may help us isolate the problem more quickly.
regards,
Alex
I need to ask a few questions to proceed:
1) were the network settings manually changed from their "automatically" default to "manually" with half-duplex and if so why
2) what type of network are we addressing? is it a single Mac plugged directly into a DSL or Cable modem? Is it dial-up? Are you plugged into a hub or a switch and if so how does the network access the Internet (through DSL, etc.)
3) are you attempting VOIP within your network or out through your connection to the Internet?
If we understand your network topology a bit better it may help us isolate the problem more quickly.
regards,
Alex
RobinS - May 13, 2006 - 12:47 am
1) They were changed but I don't know why.
2) Single Mac plugged into a high speed cable modem. Getting about 2 mb down and 300k up. No hub/switch/router.
3) VOIP is used with a softphone: X-Lite. It works better than using a VOIP ATA adapter. VOIP is used out to the internet.
2) Single Mac plugged into a high speed cable modem. Getting about 2 mb down and 300k up. No hub/switch/router.
3) VOIP is used with a softphone: X-Lite. It works better than using a VOIP ATA adapter. VOIP is used out to the internet.
mookie - May 13, 2006 - 6:50 am
Hello again,
A few suggestions and other questions.
I would tend to leave the ethernet configuration on "full-duplex" or set it back to "automatically". Without knowing anything about your cable modem I suspect that it operates on the internal connection at full-duplex.
The speeeds you are acheiving sound more like DSL than cable. Who is your carrier? How did you measure your speeds? Did you use one of the services like:
http://www.bandwidthplace.com/speedtest/
Assuming that those speeds are accurate they should be adequate to support VOIP. Is the problem a slow hand off our delays/drop outs during a conversation?
I am unfamiliar with X-Lite, but my guess is that it has an advanced network settings panel. Most products of this type will autodetect the gross characteristics of your hardware / network and self configure using a generic template. If you have such a control panel within the X-Lite product can you view the current settings? I'm interested in any setting related to network speed, bandwidth limits and QoS.
It also sounds as if you had tried other hardware VOIP solutions. Am I correct in assuming that you found the software solution to be superior?
If we can't isolate any specific setting or condition we will need to kick this back to a network specialist.
regards,
Alex
A few suggestions and other questions.
I would tend to leave the ethernet configuration on "full-duplex" or set it back to "automatically". Without knowing anything about your cable modem I suspect that it operates on the internal connection at full-duplex.
The speeeds you are acheiving sound more like DSL than cable. Who is your carrier? How did you measure your speeds? Did you use one of the services like:
http://www.bandwidthplace.com/speedtest/
Assuming that those speeds are accurate they should be adequate to support VOIP. Is the problem a slow hand off our delays/drop outs during a conversation?
I am unfamiliar with X-Lite, but my guess is that it has an advanced network settings panel. Most products of this type will autodetect the gross characteristics of your hardware / network and self configure using a generic template. If you have such a control panel within the X-Lite product can you view the current settings? I'm interested in any setting related to network speed, bandwidth limits and QoS.
It also sounds as if you had tried other hardware VOIP solutions. Am I correct in assuming that you found the software solution to be superior?
If we can't isolate any specific setting or condition we will need to kick this back to a network specialist.
regards,
Alex
RobinS - May 13, 2006 - 9:21 pm
with bandwithplace I'm getting 2.9 mb. Which is fine. "Adequate to support VOIP" just means you can hear and be heard. It hardly translates into quality audio. Vonage, Primus all suffer from a very choppy sound - both parties cannot talk at the same time. Its still very much like a 2 way radio. Same with mine. Yes, its a slow handoff.
X-Lite is more reliable though I doubt the actual sound quality has changed much. Its nicer to use a headset - but that is just comfort and sound quality. Not VOIP quality. My settings have been checked and rechecked.
Softphone is clearly superior to the lousy ATA's we had (World and Aztech). The Sipura line is supposed to be a step above.
I'm interested in isolating what controls the initial speed of the internet once you click something. even with a speed test, it takes a few seconds to get up tofull speed. Is that Ping? Latency? What?
X-Lite is more reliable though I doubt the actual sound quality has changed much. Its nicer to use a headset - but that is just comfort and sound quality. Not VOIP quality. My settings have been checked and rechecked.
Softphone is clearly superior to the lousy ATA's we had (World and Aztech). The Sipura line is supposed to be a step above.
I'm interested in isolating what controls the initial speed of the internet once you click something. even with a speed test, it takes a few seconds to get up tofull speed. Is that Ping? Latency? What?
mookie - May 17, 2006 - 10:06 am
My apologies for the delay in response. I have been out of town through this morning.
At this point I am going to have to defer to the networking "heavies" at MacOSX.com. I suspect they will need traces, etc. (do you have access to Ethereal?)
Again, I am somewhat surprised at the relatively low speeds your cable service is delivering - more like a DSL connection.
regards,
Alex
At this point I am going to have to defer to the networking "heavies" at MacOSX.com. I suspect they will need traces, etc. (do you have access to Ethereal?)
Again, I am somewhat surprised at the relatively low speeds your cable service is delivering - more like a DSL connection.
regards,
Alex
RobinS - May 17, 2006 - 11:51 am
My results again:
3.9 megabits per second
Communications: 3.9 megabits per second
Storage: 473.6 kilobytes per second
1MB file download: 2.2 seconds
Subjective rating: Awesome
Info
Date & time Wednesday, May 17, 12:49PM*
Test type IDT4 Free
Connection type Cable
Region Manitoba
Data size 1024KB
3.9 megabits per second
Communications: 3.9 megabits per second
Storage: 473.6 kilobytes per second
1MB file download: 2.2 seconds
Subjective rating: Awesome
Info
Date & time Wednesday, May 17, 12:49PM*
Test type IDT4 Free
Connection type Cable
Region Manitoba
Data size 1024KB
ericl - May 18, 2006 - 10:22 am
Let's go back to your original question:
Duplex needs to be set (on your Mac) to match whatever Duplex is set to on the device the network cable from your Mac plugs into - in your case it sounds like the network cable from your Mac plugs into a DSL MODEM.
Your DSL MODEM, being what is called in the networking industry as an "unmanaged device" is not capable being configured to different speed/Duplex settings like most computers are (cost issue), so your DSL MODEM will only support one method & you need to set your computer to use this method.
For the last 10 years or so the industry has followed a method called "autonegociate" which means when the devices are powered-up they advertise all the different speed/Duplex combinations they support, and agree on one method to use. Porblem is that autonegociate does not always work perfectly, so most folks set speed/Duplex manually.
In your case since the Mac by default will use autonegociate, somebody set this manually to (I am guessing here) to 10/half. This means you will communicate btween your Mac & DSL MODEM at 10 Mbits per second with receive/transmit being shared (half DUPLEX). This is not a problem because the connection between the DSL MODEM and your ISP is much slower than this.
In general, if you mismatch speed your network will not work. If you mismatch duplex, it will work but will be slower than it should be because there will be errors & each error results in the network packets being transmitted. These errors can be seen by running "network utility", or from the command line #netstat -i
You may run these & send me the results if you wish.
So, bottom line: if your MODEM only supports 10/half, then setting your Mac at 10/full will make things slower not faster because you will introduce errors which must be re-transmitted.
Eric
Duplex needs to be set (on your Mac) to match whatever Duplex is set to on the device the network cable from your Mac plugs into - in your case it sounds like the network cable from your Mac plugs into a DSL MODEM.
Your DSL MODEM, being what is called in the networking industry as an "unmanaged device" is not capable being configured to different speed/Duplex settings like most computers are (cost issue), so your DSL MODEM will only support one method & you need to set your computer to use this method.
For the last 10 years or so the industry has followed a method called "autonegociate" which means when the devices are powered-up they advertise all the different speed/Duplex combinations they support, and agree on one method to use. Porblem is that autonegociate does not always work perfectly, so most folks set speed/Duplex manually.
In your case since the Mac by default will use autonegociate, somebody set this manually to (I am guessing here) to 10/half. This means you will communicate btween your Mac & DSL MODEM at 10 Mbits per second with receive/transmit being shared (half DUPLEX). This is not a problem because the connection between the DSL MODEM and your ISP is much slower than this.
In general, if you mismatch speed your network will not work. If you mismatch duplex, it will work but will be slower than it should be because there will be errors & each error results in the network packets being transmitted. These errors can be seen by running "network utility", or from the command line #netstat -i
You may run these & send me the results if you wish.
So, bottom line: if your MODEM only supports 10/half, then setting your Mac at 10/full will make things slower not faster because you will introduce errors which must be re-transmitted.
Eric
RobinS - May 23, 2006 - 9:59 am
Sorry - I have a cable modem. Anyway I did something I should have done right from the beginning. I found a speed test then tried changing the settings to see if it made any difference. The only setting that made any difference was the packet size which needed to be at the maximum of 1500. So I just set the network settings to automatic.
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