Q: Yosemite Messages Screen Sharing Broken?

Hi,

I take it you are using the "iChat method" of using an AIM or Jabber account at both end to do this ?

Error 1008 replaced Error -8 but even then it was a bit of a catchall in iChat.

More generally it tended to point to issues with Ports  and particularly the behind the scenes "invite" and verification on the SIP Port.

In early iChat this was on port 5060.

From iChat 4 onwards this is port 16402

The Process works like this:-

You or the other end send the "visible" invite  which is responded to. (Accept)

The app then moves to the SIP port and sends a behind the scenes invite  and uses the SNAPMAP server like a telephone operator for this connection.

Most of it is text based - Trying, Ringing and so on.

It uses Pings to confirm where the Visible Invite went is the same place that the response comes back from.

If the listed SIP port does not work the App will try random port - See your Video Conference User Report.

The Visible invite is on port 5678

Check your Mac > System Preferences > Network > Advanced Button DNS tab has IP addresses of DNS servers and not just the Router you are using.

Check any router settings that might have changed including Date and Time.

Check the Date and Time on the Mac are set correctly.

Do not Block Pings in the router or use Stealth in the Mac Firewall.

The Messages app and IMAgent need to be allowed as Software listed on the Firewall Settings If On  ( >option Button > Allow Signed Software)

9:07 PM      Sunday; November 30, 2014

Hi,

On Both computers check the Video Menu of Messages and ensure both have Screen Sharing turned On (this setting only applies to the Bonjour and AIM/AOL or Jabber logins)

Also Check the Connection Doctor Capabilities tab and make sure it lists on both that you can Screen Share.

Whilst the connected Screen Share is Peer-to-Peer when connected the process to get there uses the SNATMAP server even for Bonjour Chats.

The Internet speed needed is the same as a 1-1 Video chat.  (If you can Video Chat you are  along way on the route to doing this.)

I would go to Messages > Preferences > Video section > Bandwidth Limit and set it to 500kbps

This is more then the Minimum for Hosting 4 way chats but does stop issues with one end being faster that the other and some variance in your (both of you) Service from the ISP.

There is some anecdotal evidence that a fast connection can out pace a slower one during the Connection process.

The Buffering in the Video chat side of Messages was designed at internet Speeds for iChat 2 and 3 and has had little adjustment since.

The max size of a pic is 640 x 480 and the max rate is 30 fps. (that's 0.3megapixels  X 30 which then has to be converted into data rates).

The app will adjust the picture size and the frame rate depending on the speed seen at App Start and the processor speed.

However if you happen to have a 10mbps download service a 5% variance (common) is about 500kbps (faster than the minimum speeded needed).

I have come across a Naming issue recently for the AIM service.

AIM stands for AOL Instant Message service (i.e it belongs to and is run by AOL)

However you can register AIM names and these can be the User Name part only  as in my main AIM name of ralphjohnsr

During the Set up process you may also get asked if you want the AIM Mail option  which gives you a email ID or username@Aim.com which is different and not the same as the the Screen Name for the app.  (which in fact tends to have a hidden @aol.com part)

This mouse over of one of my "names" in this particular Buddy list shows the Buddies Screen Name (which is of course me as well)

In System Preferences > Internet accounts the @AIM.com account is not active for Messages

Make sure the naming is "right" on your Computer for the "Buddy" and on the other end and the Login name.

It seems for Text purposes it works but does not work for Video Chats.  (I have yet to work  out why).

7:57 pm      Sunday; December 28, 2014

Where do I find the "Connection Doctor"? I can't find the "Video Menu of Messages" either.

Thanks!

Hi,

It may say Audio if you don't have or the app thinks you don't have a camera.

7:13 pm      Tuesday; February 3, 2015

I have a similar problem.

The connection doctor is showing that I have a port problem with my router.

My router has not been that friendly at opening ports.

Hi,

The Connection Doctor can show several messages.

Only one (Full Cone) will show as Green.  (not many routers use Full Cone).

Port Restricted shows as Amber and works.

All 4 modems that route that I have has since iChat 2 have worked with this method - either using Port Forwarding to a specific IP or using UPnP.

There are other so called methods listed here http://en.wikipedia.org/wiki/Network_address_translation#Methods_of_translation

I have only ever seen it not work when it can't tell what the type is.

The Link above lists 4 different types but in reality there are many cross over types that don't really fit in to the groups listed.

If you tell us what the Make and Model of your device is we may be able to help.

7:16 pm      Tuesday; March 17, 2015

Hi Raph:

Thank you for your reply.

I have a DLINK DIR-857.

Also known as an HD Media Router 3000. 

It is only 900 MBS. I bought this a number of years ago for its buffer size being larger at the time.

I started reading another one of your support comments about universal plug and play (UPnP) and the need for screen sharing to negotiate a new port number to communicate.

It may be the case that I turned UPnP off on my router for some reason (I did not know what it was used for).  

I say this because prior to the Mavericks upgrade, I had been able to perform screen sharing. 

For some reason, I have been unable to get port forwarding to work properly.

When using a web based port scanner (e.g., T1 shopper), they have been indicating the ports are still closed.

I need to work through some of this with my router. 

Hi,

I am starting at this site.

http://portforward.com/english/routers/port_forwarding/routerindex.htm

I choose DLink in the list and click it. (it show an Advert page that I dismiss to get to the following page.

http://portforward.com/english/routers/port_forwarding/Dlink/default.htm

I chose DIR 855 as the closest listed number to yours.

It will show you a list of Games and Applications

http://portforward.com/english/routers/port_forwarding/Dlink/DIR-855/

From the List I selected AIM Talk  (we are only looking up Access info rather then setting the ports).

http://portforward.com/english/routers/port_forwarding/Dlink/DIR-855/AIM_Talk.ht m

(Sorry but this site has got very advert heavy over the years)

The first Pic shows using a Browser and putting in the IP of the router.  It suggests a default.

You can check in System Preferences > Network > Advanced Button > TCP/IP tab where, lower down, the "router" is listed.

Once you do this and hit enter you should get a drop down Password and UserName dialogue item.

(the first orange-y type pic).

It has some suggestions as to the likely defaults if you have never changed them.

Username is admin and the password is blank.

There is a link to a list of other used in DLinks, if you need it.

The next three pics show the tabs across the top and the Menus down the side.  (you will notice they actually say a Dlink 825 as the interface can be similar and sometimes the same)

You don't need the Instructions at this stage.

What you do need to to check each tab across the top and then the Menus and see if any of them list UPnP.

This Emulator for a different Model says it is in Advanced tab > Advanced Network in the Menu

http://support.dlink.com/emulators/DIR615_revc/310NA/adv_network.htm

It is an ON/Off setting.

If your settings also have the Respond to WAN Pings you will need to enable this for Video Chats in Messages over AIM and Jabber (and for FaceTime)

Save your settings before leaving the page.

Go to the Port Forwarding and Disable any setting you have there.

8:29 pm      Tuesday; March 17, 2015

Thanks Ralph for that tutorial.  After rebooting the router, I had to restart the switch between the router and computer to get access to the Dlink router.  I should have done that at first before complaining that my IP address for the router was not working..

I was able to get full cone (green button) with the Dlink router after opening all the proper ports and having UPnP turned on.  

I was also able to get full cone (green button) on the Netgear router of the person I want to share screens after opening all the proper ports and being sure the manual IP address is set to be the same.   If you don't set up the manual IP address with DHCP, it will change and the port forwarding may not work to the computer one desires to use screen sharing.   My DLINK router is more advance so I can set up port forwarding on a per application basis - very cool, but I am not using that right now.  

Even with full cone on each router, we are not able to get into the screen sharing function.  After the invite is sent, and the other persons accepts the screen sharing request, we get the banner and the screen sharing noise but screen sharing is still not starting up.

I need to look and see if openDNS is blocking this or something else is amiss.

I admit I do not have acknowledge pinging turned on in the router and I just read from another one of your posts that Apple's firewall in stealth mode can cause problems, even though I have iMessage granted access through the firewall.  However, I have been trying this with Apple's application firewall turned OFF and that does not seem to help.   I assume stealth mode only works with the Apple Firewall application turned ON.

I now have a full on checklist for this of all the various pieces of the puzzle but still have not figured out exactly what is wrong with our setup.

The OSXes are the same.  We are not both capable of using the same service, AIM, GMAIL, or Bonjour (local only though).   iMessage service I think only works under Yosemite and not Mavericks (We are both using this OSx).    

Anyway the full cone on each makes me think the router ports are now OK for screen sharing with the iMessage app.

I keep wondering what has changed to disable this.  We loaded Skype on each computer and can use its limited screen sharing capabilities much easier now than the iMessage screen sharing capability.  However, Skype does not allow sharing control of one's computer screen - I have to orally give instructions. 

I have been reading that openDNS can block certain things that you may not want it to.  I need to look into seeing if whitelisting or just shutting off openDNS does the trick.     

Hi,

On the Mac in System Preferences > Networking you can set to use DHCP, Manual with DHCP and Manually.

With DHCP the router has to be set that way although it may have it's own features fro keeping the IP the same (reserved).

With Manually this is Static on all other devices and has to be set accordingly.

The "in between" setting of Manual with DHCP tends to need you to allow a set of IP addresses for the Static items.

Say the router is at 192.168.0.1 itself and allows addresses to 192.168.0.255 then some have to be excluded from the DHCP range to allow the Static computers.

Linksys devices tend to only set 100 IP address for DHCP in the first place.

The phraseology for the Ping settings can vary.

As you say the Mac Firewall calls this Stealth.

Using that Emulator link again look at this page http://support.dlink.com/emulators/DIR615_revc/310NA/adv_dmz.htm

At the bottom is SIP  (Messages and iChat use SIP to make the connection)

At the top is SPI though (Stateful Packet Inspection)

This uses the processor of the Router to try and examine the data that is coming to your computer and judge if it is valid.

However the processor is not always that fast and your Internet Connection Speed might exceed this.

Try turning it Off.

Other devices have DOS (Denial of  Service) filters that can also be threshold based and regard Video chat data as an attack as there is so much of it.

Whilst DNS may be an issue also look at IPv6

In some cases Messages can regard  this on the computer or the Router  as a separate connection to the Internet.

For the SIP connection you should have only one (Ethernet or WiFi).

Check for tethered phones as well as other standard connections.

8:44 pm      Sunday; March 22, 2015

Hi Ralph,

I'm trying to have my father share his screen with me. I have Yosemite 10.10.2.  He is on 10.9.5. We have been able to screen share in the past via Messages with no problems. Recently, this has not been working. We have been able to connect successfully, however, all I can hear is audio, but I never get to see his screen. I have been updating my Yosemite with each new release. Perhaps that's what is causing the issue?

Both computers have Audio Chat, Video Chat and Screen Sharing enabled. Connection doctor on both have green lights. Other than the updates to newer versions of Yosemite on my end, nothing else has changed. No firewalls. Screen sharing is enabled. It was all working well and now the video portion is suddenly not working.

Any thoughts? Thank you!

Scotomatic:

My experience is between  10.8  (Mountain Lion) and 10.10 (Yosemite)  using a Bonjour connection within a local area network to avoid the router issues.

I was able to share the screen only one way.

If I remember correctly, I was able to share the screen of the Mountain Lion computer with the Yosemite computer.

However, I was unable to share the screen of the Yosemite computer with the Mountain Lion computer.

With that said, I did not have full cone on the Network tab under the connection doctor with at least the Mountain Lion computer.   

I don't recall the Network tab on the Yosemite computer when I ran that test.

This would coincide with Apple making iMessages in Yosemite backward compatible with Mountain Lion but not visa-versa.

Were you unable to screen share in both directions? 

My 02 cents.

PJ'sPal,

Thanks for trying to help. I am the one with Yosemite 10.10.2. My dad has Mavericks 10.9.5. I can share my screen with him fine. It's the other way around, sharing his screen with me isn't working.

I can successfully connect with him through Messages, it does connect normally, however, I only can hear audio from his computer, but never get the video portion. My screen never shrinks down to show his screen the way it normally works.