Voice chat hics up during screensharing

Question

Voice chat hics up during screensharing

Hi all, since I did not find a special section for Messages, I post this question here. I am running a Mac Pro with Mountain Lion an Messages, my colleagues run 27" IMacs with Lion and IChat. When we share the screen it randomly happens that our voice chat in that session hics up. Sadly it is allways my voice with that problem so the only thing the other can do is to terminate my yo-yo-yo-yo and switch back to a normal chat. So I think I have to seek for the problem at my side and wonder if it could be a open ports thing or is it a bug in Messages? Anybody an idea?

Thanks in advance and kind regards, Julius

Mac Pro, Mac OS X (10.7.1)

Posted on Nov 8, 2012 6:14 AM

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Answer 1

Nov 9, 2012 2:04 PM in response to Julius from Holland

Hi,

In Messages and iChat the Screen Sharing is an Audio Only Chat+

The Plus bit being an VNC connection for the Desktop part.

It needs at least 128kbps as both Upload and Download speeds (the same as the minimum for 1-1 Video chats).

If the setting in the App > Preferences > Video Section > Bandwidth Limit is set below 200kbps you will have problems.

The same is true if for any reason the available portion of the internet connection does not give you that 128kbps.

Lets say the upload you have is only 256kbps but you also share that connection with an iPhone and iPad and a games console that is doing On line games - then the Mac and Messages may not get the require amount of Bandwidth (It is not divided equally).

Setting 500kbps in the Preferences is best.

It is faster than the min needed to Host 4 way Video chats, It also drops the speed below issues of speed variances from the ISP.

It also helps when the connection is shared.

10:04 PM Friday; November 9, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

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Answer 2

Nov 11, 2012 7:00 AM in response to Ralph-Johns-UK

Ralph good afternoon. We run both sides with no band limit. I am running on a glass fibre connection, the colleagues have a very fast DSL connection. Still your advise would be to fix both sides to 500 kbps? In that case we'll give it a test next Tuesday. I'll let you know. Kind regards, Julius

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Answer 3

Nov 11, 2012 11:41 AM in response to Julius from Holland

HI,

One thing that can happen with very fast connections is that the "natural" variance in the speed of any one moment can be too large for the buffering in iChat/Messages to cope with.

Lets say you are having a Video chat and have the Connection Doctor open (Video Menu)

This will show you the live Bit Rate and Frame rate the app is achieving.

If you then change the Bandwidth Limit to something like 200kbps you will see the bit rate change very slowly as the Buffering in the app smooths out the change.

It tried to do this during a normal chat if the Speed is varying all the time.

It does this by dropping frames until such point the audio will not be in sync and then Audio is dropped, leaving pics only.

One thing to consider is whether any variances you and your Buddy are having are in sync.

They could be getting faster whist your end is getting slower and exaggerating the change in speed.

500kbps is fast enough to Host a 4 way Video chat.

A 10Mbps service with a 5% variance is speed could be losing that same 500kbps in speed.

If your Buddy has a similar speed and also varies by 5% there could be a 10% variance overall.

Although I have spoken mostly about Video Chats here it seems that the VNC connection that shows you the desktop in the iChat Screen Sharing is more prone to stutter when the internet speed is less stable.

7:41 PM Sunday; November 11, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

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Answer 4

Nov 13, 2012 5:37 AM in response to Ralph-Johns-UK

Ralph, we did several tests. Both machines set to 500 kbps, checked the Connection Doctor. In general the Doctor tells me that the port is not fully usable due to a possible device in the network with limitations. The only one I can think of is my ISight cam that connects with a Firewire 400 to 800 jack to my Mac Pro.

I use a FritzBox router modem over here supplied by my ISP. Fritz is not fully Mac compatible. I think due their reservation of the 5060 port for VOIP in their system software. You can't add it to the preferred open ports. UPnP is also set by the way. Nevertheless connections are fantastic. My Connection Doctor shows as far as I can see only good news for the normal video chats:

So we tested the share desktop option with the bandwith limited according to your suggestion for a limitation of 500 kbps. Those specs in the Doctor also look good, still the stammering loop starts about 45 secs after the start of the screen sharing. That happened about in the same time with a no-limit bandwith.

So concluding that we have a perfect video chat with no problems points in the direction that essential ports are available and used in both ways. The desktop share works well itself. I can work over the desktop of the other and vice versa. Only the voice stammers or drops after ± 45 secs.. I thought maybe it is the ISight with no standard support for Firewire 800, but it gives my a good normal video chat...

A strange problem it is.. Anything else to try?

Best regards, Julius

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Answer 5

Nov 14, 2012 12:00 PM in response to Julius from Holland

HI,

The "Port Restricted" or other message about the router is about the way it does NAT (Network Address Translation.

There are about 4 main ways of doing this and the iChat or Messages app will only go green when it can see a router doing what is called "Full Cone".

This is unlikely to be the cause of the issue.

You have a later version of iChat that does not use port 5060 for the SIP process (after your send the Visible Invite bit)

There can be issues with some Firewire 400 to 800 adapters and the processing of the Mic's audio to the computer.

However as you say it works well in Video chats and much higher speeds.

As the Screen Sharing is on a random port with a Audio chat "Alongside" on the normal A/V port (port 16402 most likely) the audio should not stutter even when the Screen Sharing does something like playing a Video.

I am not sure there is anything left I can suggest.

7:59 PM Wednesday; November 14, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

Message was edited by: Ralph Johns (UK)

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Answer 6

Nov 15, 2012 5:12 AM in response to Ralph-Johns-UK

Thanks Ralph for all the good suggestions. I'll see and check if I can see and test another solution for the ISight and the Firewire 400 > 800 jack. and mayebe things sort out after a good bugfix of the remote client to get things more stable again. Still have to work around with an IMac with white screenshare also..

Best reagards, Julius

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Answer 7

Nov 15, 2012 12:15 PM in response to Julius from Holland

HI,

The White Screen issues is caused by the Apple Remote Desktop update to 3.6 at least.

Some people report Black Screens and others the white (Although there is also a 3.6.1 update)

Making both end have the same Display resolution seems to be the only work around at the moment.

If an older computer is the one "apparently" sending the White Screen you can use Time Machine to backstep to an earlier version of the Apple Remote Desktop folder.

Apple Remote Desktop provides the "Engine" for ichat's and Messages' Screen Sharing and also the Screen Sharing seen in System Preferences > Sharing and the Remote Management (which is Apple Remote Desktop) option that cannot be on at the same time as the Screen Sharing.

8:14 PM Thursday; November 15, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

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Answer 8

Nov 19, 2012 5:46 AM in response to Ralph-Johns-UK

Ralph I hope Apple fixes this very soon! A lot of people use the screen share option to help others or use it professionally. I cannot use our Time Machine backups to set the old RDC back because two of our IMac machines are in the 1TB harddisk replacement service. I had to make a complete and last version backup because of that which overwrote the old ones. Syncing resolutions 21" to 27" is no option.

So I'll have to wait for Apple to make a fix...

But, thanks anyway :-)

Best reagards, Julius

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Answer 9

Nov 19, 2012 11:57 AM in response to Julius from Holland

Understood.

7:57 PM Monday; November 19, 2012

Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

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Answer 10

Apr 27, 2013 3:59 AM in response to Ralph-Johns-UK

Ralph, it took some time to post another reply on this topic. I went on suffering hic-ups and freezing chat sessions. Finally I replaced my good old ISight with firewire 400>800 adapter for a brandnew Logitech C920 webcam. Problems solved! This is a very good webcam, extremely sharp and works plug and play on my Mac Pro. Chats work ecellent, screen sharing runs smoothly with no hic-ups anymore. So in the end these were hardware related problems. Kind regards, Julius

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Answer 11

Apr 27, 2013 1:46 PM in response to Julius from Holland

Hi Julius,

Glad to hear you found a solution that works for you.

Thanks for coming back and letting me know.

9:46 PM Saturday; April 27, 2013

 iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.3)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images."  No, Seriously

Reply