Cannot screen share via iMessage

Hi,

Apple IDs still work as AIM Screen Names if that is what you are getting at.

However they do have to be linked to iCloud IDs.

So older @mac.com IDs that you might have been using in older versions of the OS need to be able to do a sort of 2 Step Verification on the Password.

The same is true of @me.com IDs not moved over to iCloud.

It's about that version of iChat being able to do it rather than the ID not working at all.

I have active @mac.com IDs in Sierra that do not work in iChat 5.

iChat 6.2 is the cut off.

However as you then clime the Messages Ladder (Version 7 through 10 in Sierra with two version eights along the way) then you lose some of the iChat functions.

Formatting the messages, (Different colours in Group chats and different Fonts and so on)

Video/Audio chat from the AIM and Jabber accounts

The Screen Sharing that was part of that.
The Sound effects linked to different people for different actions.

iMessages has had the function to Start FaceTime for Video and Audio Chats.

Later the ability to launch the Screen Sharing app from inside Messages was added which does include an Audio chat.

(i.e. Messages now launches outside apps for the iMessages account only.

This does force you to use the same ID in FaceTime as well as the iMessages account so people know who is calling.)

Ports.

Your Internet connection is effectively divided into 65665 ports

On most routing devices (modems and routers that allow you to connect more then one device to the Internet) can control these ports.

Normally the first 1024 ports are Open anyway.

Browsers use port 80 for example to fetch most pages.

Some use port 443 for secure logins (Apple does here for you to login to Post)

Mail uses many ports that are in this lower group.

It is common fro outgoing mail to go on port 25.

Incoming mail depends on the service provider but looking in Mail and the Preferences and using the option to look and Edit the settings tends to show you the ports each service is using. Ports 110, 443, 567. and 998 are common.

FaceTime uses these

https://support.apple.com/en-gb/HT202078

The iChat ones are in this Doc Using iChat with a firewall or NAT router - Apple Support

It does state it is no longer supported and it is not an easy read.

This page http://www.ralphjohns.co.uk/versions/ichat3/ichat3pics/Firewall3/PortsinFirewall .html has a table of ports and which are used by which service. It starts also with a very old pic of an earlier Mac firewall settings.

Since that version (iChat 3) things have changed.

Later iChats and Messages uses port 443 to login to AIM.

Port 5190 is still needed to transfer files and pics.

Port 5060 is not longer used.

Like the HTML protocol uses port 80 for Browsers various other internet items uses a specific Protocol.

iChat uses SIP (Session Initiation Protocol) meaning it had specific ports to use. Port 5060 is one of the range for that.

However many ISP (Internet Service Providers) and some Internet Backbone services tried to block SIP (it effectively allows computers to make "free" calls) and you then had to pay more to have the ports opened at the ISP end.

Apple's and Skype's answer was to use the protocol but force it into other ports

Apple used the same ones and the Video chat itself.

The text side of iMessages uses port 443 to login

It also uses port 80

Port 5223 is used to get feedback from the iMessages server as to who of your Buddies is On line.

As you can see this is a port that Jabber connections also use to login to some Secure servers.

As iPhones are effectively always On it make little difference as you can't see in the app who is on line until it fails.

Mostly this will be when an Apple ID is not available as the Mac is Off.

Anyhow...

The Mac Firewall has long been changed that it will open ports if the App is listed in the settings for the Firewall.

This also tends to include processes used by the app such as File Sending (includes pics) and the login process that strangely does not have Messages in the name.

Ports in a routing device can be set to be open in several ways.

If you are using an iPhone as well as a Mac it can be best to use the UPnP settings.

(Universal Plug and Play).

This allow a device to tell the router to open the ports and keep them open for a period after use.

It therefore says having to bother list each and every port that might be used.

A boring long piece about the different methods here http://www.ralphjohns.co.uk/page3.html#_ports

Again written about the time of iChat 3.

Most routing devices have improved the amount of control you have nowadays.

Summary.

Only the iMessages side will invoke Screen Sharing.

This means having an Apple ID that is iCloud Valid.

The Mac firewall will allow most connections without needing any specific setting.

If it does not seem to work then list the Messages App in the list.

Most routing devices which includes modems that can link to several devices by WiFi or Ethernet (Strangely those holes/plugin bit are also called ports) have a method called UPnP.

This allows the app on the device to tell the routing device to allow the ports to be open.

It also allows this to be used by Multiple Devices.

The Apple Screen Sharing app is part of Apple Remote Desktop (ARD)

See this table of all the common ports used by Apple TCP and UDP ports used by Apple software products - Apple Support

Then from an iMessages chat the Details "button" top right will start up the Screen Sharing app for you using the interlinked rectangles icon.

I would set up iMessages first and get the chat working.

Then see if the Screen Sharing will work.

I would tend to not worry about the ports for the moment.

9:50 pm Wednesday; September 20, 2017

Ralph,

This all used to be so easy with iChat. My 86 year old mom has "problems" regularly and iChat was simple to use. We both had AIM accounts which I understand Apple is unable to use with messages. I have tried relentlessly all of these items and even more so that I can share and control her screen. I am ultimately in a state of frustration with the Apple Koolaid. I have the bonjour, AIM and iMessage accounts all enable. I am looking for a simple and sure solution to get the screen sharing to work again. I have flowed your posts before and they are great, better than Apple genius technicians which have been unable to help. Very disappointing! Is there another piece of software or freeware that works. I don't know where these "ports" are located or how to turn them on, so I am open to more instructions. Thanks.

Ralph, Thank you for your response. The bottom line is my mom and I need an Apple account number and log in and we must turn on back to mac in the services. Like i mentioned i don't use icon for anything else and will leave them turned off. Second the message i received is that yes, Apple messed up a good thing that was easy to use with AIM.

The sad part is my mom has no idea how to set up and account or iCloud log in to back to my mac until i can visit her. If thee is another way to control her screen with free third party software, I would be interest in that too. Maybe Skype does this??

But again, thanks. I've followed your posts for a long time.

Mark

Hi,

It is a very long time since I tried Skype (even before Microsoft bought it)

Back then it was sharing peoples internet connections to make it work (different from AIM that used their Own Servers and also Peer to Peer connections like iChat did).

If you were using Little Snitch to check the connections that an App was making you spent most of the time agreeing to upwards of 40 connections (I had an AIM Buddy who claimed once he topped out at 100)

That made it more susceptible to Man in th Middle attacks so we both gave up on trialling any further.

That said I can't say I have heard of any security issues with the app.

I have not kept up to date with other similar apps.

8:38 pm Thursday; September 21, 2017

Hi,

There are now two methods to Screen Share starting with the Messages app.

Method 1 (the 'iChat" way)

This uses accounts from Jabber or AIM at either end (i.e the two internet accounts that can Video and Audio Chat as Yahoo ones don't and Bonjour is LAN only)

For this the Video Menu needs to have Screen Sharing Enabled at both ends.

It can be confusing as a Apple issued ID (@mac.com an iCloud linked @me.com or an @icloud.com ID can also be used as an AIM Screen Name.

SO you need to be clear about which method and where the ID is being used.

The Method then means displaying the Buddy List.

You then highlight the Buddy and either click the Screen Sharing icon at the bottom of the Buddy list or use the item to start Screen Sharing in the Buddies menu.

To AIM to AIM (Or Jabber to Jabber) DO NOT use the Details drop down as this invokes the iMessages method and leads to failure.

Method 2 (The iMessages way).

To set up you need to go to System Preferences > Sharing > Screen Sharing and enabling this. (you may need to consider who is allowed to use it if you are the one sharing).

Then in an iMessages chat you can use the Details drop down and the Screen Sharing icon should be available.

This means it is iMessages to iMessages but only Mac to Mac.

Like iMessages invokes FaceTime for Audio or Video chats this Invokes the Screen Sharing App.

NOTES.

The screen Sharing app is part of the Apple Remote Desktop set up.

The app itself is actually in Hard Drive name/System/Core Services/Applications

It can also be invoked on a LAN when you connect to another Mac and you are offered the Share Screen Button.

It can also be used in the Finder > Go Menu > Connect to Server and using VNC:// instead of SMB or AFP to start the address.

Whilst every method described here is part of Apple Remote Desktop or at least it's "Engine" there are some differences

Both Finder methods do not have Audio chats along side.

The 'iChat way" uses the same method as a A/V connection and can be considered to be a Audio Chat with a VNC screen display.

The iMessage way seems to be a VNC connection with an Audio chat streamed alongside (it may actually be added but I have not worked that out yet).

9:46 pm Wednesday; May 13, 2015

Hi,

Any chance the System Preferences > Sharing > Screen Sharing set up is set to Administrators Only ?

This would mean only Admin people set up with accounts on your computer could access it remotely.

The same would be true at your father's end.

This might be too much access...

As it lists All Users.

On the other hand this restricts it to Admin Accounts on your Mac.

If it is not that we have to look at the Firewall and whether it is allowing the Screen Sharing App.

It should be listed in the top section of System related stuff.

This might have prevented it's direct use as well.

However you need to list the Public IP address when using the Finder's Connect to Server and then set up the router to forward the port used to the Computer involved (Messages does this bit for you whichever method you use).

Apple Remote Desktop uses port 5900.

Recently there have been posts that people find that iMessages will not connect and this is related to their use of McAfee which then blocks Messages until it is allowed specifically.

It seems that Kaspersky has a similar issues as well after the OS X 10.10.3 update.

It seems the update effects the way these Apps are set up and the use of the internet by some apps.

Of course in this case you would need to check on the use of the Screen Sharing App rather than Messages if you have such an app.

9:11 pm Thursday; May 14, 2015

for the Points.

If you need any more help then continue in this thread (it will be a long while before it is archived (viewable only) ).

To be clear "Adminstrators" have to have Account (Mac User Accounts) on that Mac to be accepted. Of course you would have to know the name of that Admin account and it's password.

Hope it works out.

7:40 pm Friday; May 15, 2015