Changing screen share speeds?

Hello
We have comcast cable. For whatever reason, whenever someone was using iChat to video chat, every other connection in the house (ethernet or wifi) would slow to a stop. I changed the bandwidth to 500kbps on all computers and the issue was resolved.
However, we noticed that if one computer does a "screen share" via iChat that the same problem still exists. How can I change settings to relieve the screen sharing from blocking the whole up/down speeds?
Thanks for the help

Hi,
My first though was Hummm.
The Video Data is made up by iChat assessing the Internet Speed and Processor speed and giving you a certain size pic (pixels) at a certain Frame rate.
With the Bandwidth in the Video Preferences set at NONE and a Intel Core Duo at least you will get 30 fps with a pic at 0.3Mp (640 X 480 pixels) when your Internet Upload speed is above 500kbps
This tends to be the standard pic size for anyone running an Intel Mac.
Older G5s and G4s will depend on Processor speed and whether they have Dual Processors.
iChat can reduce the size of the pic (Less pixels per frame = Less data a sec) based on the Internet Speed it can see and then the Processor speed if if feels that is too low.
This can be seen somewhat directly based on the size of the Video Chat window iChat opens for you (Although this can be manually resized).
Typically on my G4/1Ghz Dual Processor with an Upload speed of around 750kbps I see speeds reported in the Connection Doctor (Video Menu) of around 400-500kbps for a 480 X 320 pic at about 15fps
My MacBook Pro sees the same sort of speeds but for a 640 X 480 Pic at 30fps
The reason for the Humm is because typically Screen Sharing comes in at about a 1/3 of that (About 150kps in the Connection Doctor) whilst 1-1 Audio chats come in at just under Dial-Up speeds at about 48-50kbps (possibly the max for a 56kbps Modem) - even when iChat is set to 500kbps.
At NONE the Screen Sharing and Audio Chats does not vary upwards a all.
I can run 3 way chats with my two computers and a Buddy (Mostly the Apple Test accounts) and not effect my son using his X-Box 360 with On-line games.
If your Connection Doctor is reporting similar speeds fro Video chats and Screen Sharing then I would test the Connection speed.
http://www.speedtest.net/
You should see results that are about 80% of the Max Speed quoted by your ISP that you pay for.
This is in part to losing some to maintain the connection with the ISP and the Test itself.
The results can be effected by what is On line at your house at the time:-
Someone doing Downloads, Watching YouTube or other Video Streaming, even LAN games and On-line games and other IM apps.
Also see this Apple Article for iChat 4 (Leopard)
Figures do not vary greatly for iChat 5 (Snow Leopard)
These figures and the Info do suggest that Screen Sharing could take up to 300kbps
I have never seen figures this high but if you are seeing them that high then a further reduction in the iChat Bandwidth Setting may help.
However anything below the 500kbps setting will impinge on your ability to Host 4 way Video chats. (Don't even bother with the 100kbps as it is too low for Video chats 1-1)
7:26 PM Saturday; March 26, 2011
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"

Similar Messages

Change screen share keyboard shortcut

Hello,
I just got a new keyboard that connect to multiple computers. Very helpful...however the Command F2 button actually registers as Command F15.
Is there a way to change my share screen shortcut or change what my keyboard perceives is happening so I can use share screen from this keyboard?
Any help would be great!

Sure does seem to be missing from the obvious places, doesn't it? Probably because it's not actually in a menu anywhere.
Recording an action does yield a bit of a clue... It records as Merge Visible With Duplicate:
The Alt seems to add the "With Duplicate".
Just a guess, but based on the above, if you were to change the Merge Visible shortcut to something besides Control-Shift-E you might find that adding Alt to whatever you assign to that function would be a Stamp Visible operation. I didn't try that.
Or you could record an action as above and assign it a function key.
-Noel

Screen Share - Change what to display & video quality

Hi LCSS Team,
I have been playing around with screen share and have it working in collaborative (both ends can share/control their screens).
Upon initial selection of deskop/app/window, is there a way to allow users to change what to display without having to
start/stop?
Use case:
- User A is viewing user B screen. User B would like to change view from desktop to a specific window.
Also, the screen share video feed is very pixelated. I have tried it multiple settings including what you guys sent
me. I am trying to get it to Skype like quality. Is that even possible?
Thanks,
Michael

Hi octoguy,
iChat makes hardware and connection speed checks as it starts up.
This gives you the framerate and bit rate duirng a call.
Lets say that your processor gives your iChat 15 fps
This will be the rate that you will then see to a another Mac.
The same computer is likely to get 10 frames per sec to a PC.
This is some part due to the PC putting a fair amout of effort into producing a clear detailed pic.
On some PCs this setting for the video pic is so high that the audio will drop out completely.
The cure is to bring the PC preview to the front (tabs)
Then click on the small icon that appears to the right and adjusting the slider that appears to the left.
This will incease the frame rate and bit rate from the PC. It makes the video look smoother although the actual quality has gone down (you may not be able to judge this quality difference by eye)
As general rule you will get about 2/3rds of the normal Mac to Mac framerate shown in the Connection Doctor. It also seems to take about 50% more Connection speed to get the same quality video.
So Mac to Mac min is 100Kbps where as Mac to PC will need about 150kbps.
The quality drop from 15 frames a sec to 10 frames a sec does make the video generally more blocky but does also depend a fair bit on the processor power of the PC and the camera used.
I know that sounds a little vague but there are really many variables that can be a factor.
11:23 PM Monday; April 24, 2006

Screen Share - Freeze when changing accounts

When I try to change change to another account on the iMac via Screen Share, Screen Share freezes. In fact, this happens when trying to log in to another account--it does not show the log in screen.
If I Quit Screen Share and then open back up, I can then see the other account or the log in screen.
All advice appreciated.
Tony

Ok found the problem.
As said before brand new device, when installing I choose to restore an iCloud back-up form my previous iPhone4.
Somehow, and I surely do not understand why! My new 5S not only had all my keyboards as it should because of the recovery, it also had the German keyboard? Which is not part of the recovery!
Deleted the keyboard, problem solved.
It still is very strange I only had the German on "some" screens not all.

CAN'T SCREEN SHARE! TRIED EVERYTHING! PLEASE HELP!

My girlfriend just got a new Macbook and I've been helping her set it up across campus though our network at my university. It worked fine and then one day it didn't. Every time she asks or I ask to share her screen it gives this error to both of us:
"Failed to start Screen Sharing because: Screen sharing could not be established."
I've been reading discussions on how to fix this for 2 weeks now and nothing has seemed to work. What is weird though is that I can screen share PERFECTLY with my Uncle who lives in Wisconsin (I am in Arkansas) from campus. However, I can't seem to connect to my girlfriend's computer who is simply just a few buildings away.
The following is what we've tried:
1. Switch from wired to wireless network
2. *Set "System Prefs>Quicktime>Streaming" to "1.5 Mbps T1/Intranet/LAN"
3. *Set "iChat Prefs>Audio/Video>Bandwidth Limit to both "500" and "None"
4. *Both computers have a firewall set to "Allow all incoming connections"
5. *When #4 didn't work we set firewall to "Set access for specific services and applications > iChat.app set to "Allow incoming connections"
6. Rebooted both Macs
7. Deleted all com.apple.iChat.X.plist files and started over fresh
8. *Enabled "Screen Sharing" in System Prefs>Sharing
*Restarted iChat afterwards
I think that's all. It is just really frustrating because I can screen share with someone clear across the nation but not someone who is on my same network. The only difference is that she is using a Gmail account through AOL and I am using a @me.com address. I thought maybe Gmail wasn't working so I had her switch to an AOL account and still same error.
We cannot port forward for obvious reasons at school but it worked before and nothing on the firewall has changed. I work at the IT department at our university and spoke with the person who runs the Firewall and supposedly there are no blocked ports on the part of the network we use. I know with iChat 4 in Leopard it doesn't use a specific port, it bounces around until it finds one according to article regarding port forwarding and NAT routers and iChat.
The weird part is that when we are both off campus (different houses) and try it, Screen Sharing tries to start, she gets the big words across her screen ("Screen Sharing Started" I think...) and we can hear about 5 seconds of audio and then it errors out again. I really want to get this working can someone please tell me how? This is really frustrating.
Thanks,
-jg

Hi,
First off from reading this it should be an AIM valid name (@mac.com, AIM or @me.com) to AIM valid name or
a Jabber valid name (which includes Googletalk valid Gmail IDs) to another Jabber valid name
(that is both should be using the same type of Buddy list)
As you say the Apple Doc on this is not clear on the Screen Sharing part - listing only the changes to the AV ports compared to the Previous Doc (Now article HT1507). It does not mention the Screen Sharing at all.
Reading around suggests the Screen Sharing is based on Apple Remote Desktop and reading the com.apple.ichatAgent.plist with QuickLook shows a reference to a ARD link/process. (the same can be seen if you install Developers Tools from the Install disk which will give you Property List Editor which will open the .plist files).
The Article TS16929 (Previously Doc 106439 shows that Apple Remote Desktop uses port 5900 and 5988.
Having said that though I run Little Snitch, an application that monitors and reports which IPs and Ports and application is trying to use. This shows me a completely random port in the 15xxx range along side the AV port 16402 for the Audio component. It maybe that Apple Remote Desktop also moves to a random port after it has established a connection.
Most people fail on the Audio part and get the standard Log Pop up screen to send or not to Apple - BUT you clearly have the other message...
"Failed to start Screen Sharing because: Screen sharing could not be established."
.... which is unrelated to the Audio part.
This would clearly put things in to the realms of a firewall or setting issue with possibly modem/router or LAN features getting in the way. (Leaving aside ISP related things for the moment).
You say iChat is in the Allowed Specifics List in the Leopard Firewall.
You say that nothing has changed on the Campus Firewall and can connect Off-site form On-site so it would seem not to be there.
On this last issue, check if they have introduced a Streaming cap on Intra-Site links. They may be trying to prevent other things such as Peer-to-Peer File Sharing or thing like everyone sharing their iTunes Libraries and other similar activities. The ability to Share Optical Drives re MacBook Airs maybe a factor.
I would tend to look towards your girlfriend's Mac.
Since iChat 2 it seems that some failed chats seem to hold on to ports or have some hold over the Network going on.
It seems most common when in System Preferences > Network the drop down at the top listing "Location" is left at the Automatic Default.
There are essentially two fixes for this.
1) Set up another Location and copy the settings across and switch between the two to force the Network to re-establish itself.
2)A longer way of clearing what is going on.
a) Shut any Airport card down if using WiFi
b) Shut down the computer.
c) Disconnect any Ethernet cable from either Computer or routing device (whichever is easier to reach but leave the routing device still connected to the Internet - just isolate the computer from the Internet)
d) Restart the computer (this is with no Internet Connection)
e) Restart iChat.
f) Restart Airport card or plug in Ethernet cable.
g) Using the Buddy List, select Available and make iChat Login (can also be done from the iChat Menu (> Accounts submenu in iChat 4)
On your last paragraph I would ask if you can Video chat at this set of locations ?
This is because in this scenario a feature of one of the modems may be an issue.
Some modems and routers have DOS (Denial of Service) or SPI (Stateful Packet Inspection) protection. These tend to be threshold based and have no setting control in the devices set up pages (other than On or Off).
iChat can stream so much data, particularly in Video chats over what are now quite high Internet speeds that a DOS feature will consider it an Internet attack and cut the port involved. SPI tends to be judging whether the data stream is valid and does not seem to keep up and the result is the same.
In Video chats the end that has the Problem tends to get a Error -7 In the Log.
The Other end gets the "No Data for 10 Secs" message.
Summary.
Essentially though as you have tried a deletion of all the .plists for iChat and you imply both ends it is more likely something about the Network or how the Mac thinks Network resources are already allocated.
There is not an easy .plist deletion for this hence the two methods listed above.
NOTEs: 1) #8 in your list is not related to iChat.
This is what you can now use of Apple Remote Desktop itself. It has it's own Screen Sharing app (without Audio like iChat) that is invoked from the Finder's Go Menu > Go to Serve and entering a VCN:// IP address. (As a System Application, as it were, it is in /System/Core Services/Screen Sharing.app)
It does need both Macs to have the Setting Enabled as you have done it #8 though
2) Some ISPs it is suggested block Screen Sharing. (Verizon was the name I heard mentioned). How they tell what the data steam is specifically I do not know as it would seem that the Audio part of an iChat Screen share would make it look like an A/V chat and that Apple Remote Desktop must be a valid way of working for some people. However iChat is Peer-to-Peer in AV chats and Screen Sharing and some ISPs are known to actively work against these file sharing apps that bear the same generic term.
In your case I do not think this applies as you can Connect Off site via whatever ISP your Campus uses.
I hope this helps.
9:58 PM Wednesday; October 1, 2008

IChat screen share... what else?

I persuaded my Grandparents to buy Leopard specifically for screen share, but no luck so far. In fact, being home, I'm sitting in their house right now sharing their internet with airport and I STILL can't get even audio to work. I can connect with Leopard's screen share facility and with Chicken of the VNC easily, but not with iChat.
I wondered about .Mac though and the back to my mac feature. If anyone out there has it, does iChat work any better for you? With the persistent share, I figure maybe it would be easier to resolve the connection.

Okay, so I have it working... not sure what I changed, though. CotVNC does work after setting default profile to "let server decide" for color scheme. I was hoping to take it black and white to improve performance, but no can do I guess. It's a little picky if you want to kill the audio portion by turning off the mic. I can't get it back unless I quit out of iChat completely.
Nevertheless, it's working and one satisfied customer. It's speed is better than any VNC through home networks I've ever used, and the ease of connection (once you get it, of course) is equally impressive. Though I would appreciate a key combination to switch between my screen and the shared screen without having to have them stop what they're doing so I can navigate down to my window.

Video and Audio work but not screen share

I am able to connect and video chat with a mb running 10.5.4.
When I request screen share, they authorize, seems to start to connect then I get the message "screen sharing could not be established."
Is this a port issue?
Thanks in advance!

Oh My !! You are doing things the difficult way.
Hopefully you have got both ends set in System Preferences > Quicktime > Streaming to 1.5Mbps
(if you have to change iChat will need restarting).
In the iChat Menu >Preferences > Video Section > Bandwidth drop down both ends need to be on 500kbps to get around what Comcast and Road Runner do to manage their Data Stream. This can be set in a chat. The two ISP s do things to try and stop people using File Sharing apps like BitTorrent but it impinges on iChat.
The reason why I say it is a port issue.
I run an App called Little Snitch.
It tells me the ports and the IPs applications are connecting to.
In a successful Video chats I see port 16402 on people's Public IP and if they have a Router a LAN IP as well.
When in a Screen Share situation I also get another port.
Screen Sharing in iChat iss related to the way it is/was done in Apple Remote Desktop (ARD).
in fact in the iChatAgent .plist you can see the Setting
(It is in fact Off in this Pic)
Apple Remote Desktop uses port 5900 and 5988.
However, Little Snitch reports to me a fairly random port when I use it and shows a number in the 50000 range.
I use UPnP in my combined Modem/router which seems to cope with this random port.
UPnP (Universal Plug and Play) allows any port the App wants to open to be open - control is with the App.
This Doc by Apple tells you the ports to open if Port Forwarding for iChat 3
It includes the Bonjour ones, the Jabber ones the AIM ones and the A/V ones.
http://support.apple.com/kb/HT1507?viewlocale=en_US
This second Doc by Apple is about the port changes to iChat 4
http://support.apple.com/kb/HT2282?viewlocale=en_US
This one only tells you about the A/V ports and not the other you need.
AS it is short on info that is known about it stands to reason the info on Screen Sharing ports is also missing.
This link is about the Linksys WRT54GS
http://portforward.com/english/routers/port_forwarding/Linksys/WRT54GS/iChat.htm
Near the top of the page is the Info to use in a web browser to access the set up pages.
Follow the Instructions to to access the device and set the Unblocking of Anonymous Pings in the Security page.
Stop following the Instructions and go to the Administration page.
In here you will find UPnP.
This should be Enabled (Save Settings if you need to)
You will see in the rest of the Instructions that Port Forwarding is in Applications and Gaming as a sub tab. If anything is set here it will need to be Disabled.
As will anything in Port Triggering and DMZ tabs.
The Linksys WCG200
I can not see the one with cc at the end on the Port Forward.com list so I have picked version 2
http://portforward.com/english/routers/port_forwarding/Linksys/WCG200v2/iChat.ht m
You can see the pics are similar.
Although it does not say, also disable the Block to Responses to Internet Pings on the Security page (as well as having the Firewall Off).
Then do the same as above. Enable UPnP and Save Settings - Disable anything in Applications and Gaming and again save settings.
As I said before UPnP will allow the apps to open the ports they need and will therefore cope with the fact we don't know the precise port iChat is supposed to use.
Out of the Box list.
Apple have a list that was started at iChat 2
http://support.apple.com/kb/HT1787?viewlocale=en_US
Although the Doc was updated in June this was only for the new numbering system.
You will notice under the table that some still need tweaks.
Realistically most devices will need some tweaks and turning on UPnP can be the smallest.
Most Netgears have UPnP on by default.
However they have the Internet Ping Blocking and they have a DOS or SPI firewall that can impinge on iChat 4 as all the data is on one port and Faster internet speeds mean more data can be sent bumping into the threshold that these work (And get in the way).
MIMO devices that tend to come with two or more antenna are a problem for iChat as the Wireless signal is effectively duplicated and iChat see this as two network connections and can not use them - if you are thinking of being wireless.
9:04 PM Wednesday; August 20, 2008

I'm trying to use Mountain Lion Server so my family can have separate logins via Screen Share to their iTunes.

Using Mountain Lion Server so my family can have separate logins and connect via Screen Share.
Works great, each has their own home directory and permissions are perfect.
Now setting up iTunes for each with their own Library (not shared), thus keeping multiple Libraries.
I get this;
This Computer is already associated with an Apple ID.
If you download past purchases with your Apple ID, you
cannot auto-download past purchases with a different
Apple ID for 90 days.
What!
So what it is on the same computer, they are completely separate Libraries never to be mixed.
If this works, I only need to keep one computer up and running, instead of three.
Each can do their syncing/backup and connect to the various Airplay/AppleTVs I have around the house.
How do I fix this.
Thanks

Bottom line is you can't - easily.
You need to make sure that you log out of the server each time otherwise the ID is running. To explain, if you had a laptop with different people using it, your solution works fine. Each time someone logs in, the iTunes ID is different so it works as you can only have one person using the laptop at any one time.
Now, turning your problem inside-out, you want people to be able to log into iTunes concurrently to use their own version of the program with their own library. This does not seem to work and you get the conflicted ID error message. Even though iTunes is running under their own login ident, I have never been able to get this working reliably and was told that iTunes is NOT a network-aware application as it is designed to be single user.
The way I got around this was to login as XYZ and to make sure that the ID was changed in iTunes accordingly. However, it did not always work so I gave up with the whole thing.

Cannot Maintain Stable Screen Share Connection New MacBook Pro

I am having some difficulty maintaining a stable screen share connection. It just keeps disconnecting and reconnecting. It has nothing to do with my network as I have tested it from 5 machines and it's only this one.
Has anyone else experienced this with the new MacBook/ MacBook Pro's?
I have  MacBook Pro - 15" 2.53Ghz/4GB RAM/320GB @ 5400RPM
Thanks,
Dean

A little update. I have found what caused this.
When my MacBook Pro was trying to Screen Share to my iMac it would ONLY drop out when connected to this particular machine. The iMac is a 24" Aluminum 2.4Ghz it is running @ 1920 x 1200 with a 23" Apple Cinema Display connected to it @ 1920 x1200.
When I mirror the display the screen-share connection stays stable. Only when I change it to Extended does this issue occur. I am wondering if any other users have experienced this? Possibly it could be a bug in the OS as it doesn't like multiple displays during screen share.

Cursor location in screen share is different on both screens

When connecting from one laptop (Mavericks) to another laptop (Mountain Lion) the cursor in the screen share is in a different location than on the computer being shared. I have the ML laptop hooked up to a TV and use the Mav laptop to control it. The cursor on the Mav laptop does not match up with where the cursor is on my TV. Any way to fix the offset?

TC6.0.1 is very old. I'd recommend that you upgrade your software to a newer version. The newer releases have a number of bug fixes and changes which may assist in your configuration as well as some fixes for some major security vulnerabilities.
If you have an active service contract, you should be able to access the updated software on the Cisco Download Web Site.
If you don't have an active service contract, contact the TAC and, as per the "Customers Without Service Contracts" section under "Obtaining Fixed Software" in the Cisco Security Advisory cisco-sa-20140926-bash you should be able to get an upgrade to at least version TC7.2.1.
Wayne
Please remember to rate responses and to mark your question as answered if appropriate.

Latency using Screen Share

I am experimenting with Screen Share in Lion (did not use in SL) and am having latency issues. MacBook taking control of iMac i7 quad core not too bad but iMac i7 Quad Core controlling MacBook is horrendous. Any ideas to speed things up?
Also trying to connect either way using "Apple ID" not working, only will connect using "Registered User" any thing to help out here would be great. Thanks

Just updated to 10.7.1 and all seems to be working great!

Can't screen share on local network

Hi folks,
Seems like lots of problems are to be had with the iChat screen sharing. I've been looking through here and tried several options, but I don't seem to be able to get this working.
My MacPro 2x2.66 is sitting in the DMZ of my DSL Router and a brand new iMac is sitting behind the router's firewall, but on the same network. Both are running updated versions of Leopard. I've followed the instructions for NAT port forwarding on the router found here:
http://web.mac.com/valsjo/personal/Start/Entries/2007/12/8iChat_screen_sharing_problemsolved.html
and also made the necessary changes to the Apple firewall (although I actually just have "accept all incoming connections" checked rather than listing iChat and my many other apps individually).
These two computers can't seem to screen share, however, with the dreaded "Screen sharing could not be established" error. Why is this happening when I'm on the same LAN?
Video chat appears to have similar problems.
Thanks for your input,
Aaron Genest

Have you tried Bonjour for screen sharing on your local network?
It works without problems on my local network, these are the settings that work for me:
Enable Bonjour messaging in iChat preferences>select use Bonjour instant messaging.
With iChat open select "enable screen sharing" from the top menu>video
In order to get it to work on my local network I had to disable screen sharing in Apple menu>System preferences>sharing.
The firewall settings are set to specifically allow the iChat application.
These settings should be set on all Mac's on your local network you wish to use iChat screen sharing with.
It might not work with a mac that has the file vault feature enabled.
My router settings are in default.

Screen share using Linux?

Will screen share work with a Linux machine?
How many people can be on that call at one time?
Thanks.

Good evening Lirein,
I've been doing some sniffing around and it looks like the only way I can get Skype to behave for screen sharing with more than one viewer is to use a Windows machine, sigh. Right now Skype screen share works about half the time.
I've tried lots of other programs for screen sharing on my Linux setup and have not yet found a good answer. The best so far has been Mikogo. Unfortunately they do not support a 64 bit system and that throws a wrench into my works.
To use a screen sharing program I will have to reluctantly use a Windows machine. I hope that changes some time soon.
Thanks for your reply.
John Teisberg

Screen Share frame stops

Hi Guys,
I got screen share running pretty well now. Quality is as good as it can be but what I am running into the freezing frames
every few seconds. I can see flash animations run on the host PC that is streaming to mine but every 5 to 7 seconds, the
frame stop for about two seconds and it keeps going. This has happens every 5 to 7 seconds.
Any ideas on how to get rid of that?
Thanks,
Michael

Hi Michael,
Unfortunately, screensharing isn't really great for sharing animations -
it's CPU intensive to capture, encode, and send frames, so in general it
won't be able to keep up with an animation's speed.
nigel

Screen Share Cuts Off Internet

Well, I recently upgraded from a basic laptop to a beefy gaming computer, and skype is working great except for one thing. Every time I screen share, about 1-5min into it, I loose all internet connection on my computer and go offline. I don't know how or why this is happening, because my internet is fine otherwise and I can host calls and game online at the same time. It only looses connection when I screenshare, no other time. I've tried this with different people, but always the same result, so I know it is something on my end.
I'm running Skype 7.5 (just updated) on Windows 8.

The Dlink DI-604 is listed on the D-Link site as a Mac Compatible product. If they have said it is a know recurring problem, then I would ask for a replacement/refund and move on to another router.
However, if you want to try and use the router, we will need more info on your connection. Is it a cable or DSL modem you are connected to. Are you given a Static, or Dynamic IP from your Internet provider. Are you using the default settings in the router, or have you made any changes.
Tom N.

Changing screen share speeds?

Similar Messages

Maybe you are looking for