VCN only while connected via internet address?

Question

I have scoured all the posts here, and searched every phrase I could think of, and read the manual to find the information I am seeking, but I cannot seem to find an answer. I have found similar posts/complaints but no solutions.
I have ARD 3 on my MacBook Pro, and I use it from my office to assist my wife, who works at home, and my mother, who lives in Canada.
My wife's PowerBook is correctly configured in the System Preferences > Sharing > Services pane. She is on a fixed 10.x.x.x IP address behind and Apple Airport Extreme, with ports 8283 and 5900 forwarded correctly to her machine.
My mother has a cable modem (COGECO cable, Canada), fixed IP address, an NO router.
In both cases, firewalls are disabled on their machines.
In ARD, I can see both machines by their DNS names in the list. Status says "offline", but if I open either of them, I see their screens and am able to rudimentarily control both machines. What I cannot do is any of the other Management tasks, like System Reports, client Upgrades, etc.
Is there something inherent in ARD 3 that forces machines connected over the Internt (vs. LAN) to only be controllable in VNC mode? Or am I missing something here?
One question: in the client computers, should the System Preferences > Sharing > Services > ARD > VNC viewers may control screen with password, be checked or unchecked, and does it matter if I am logging into the machines via an admin account I created on both?
Thanks in advance for any useful tips!

Answer 1

Kevin,
it appears to me ... though I am a *total amateur* and only know what I've gleaned from these boards and the net in order to setup ARD for myself ... that for those using Airport networks (lots of us) it is necessary to manually open ports 3283, 5900 in the Sharing preferences under Firewall. If not, the traffic doesn't pass ... even on a LAN. So, you need to add a New configuration in the Firewall tab. (IOW it is NOT enough to simply select ARD in the "Services" tab).
This appears to me to be the problem with VNC over the net ... although I'm not sure that it's a problem really.
I have ARD 3 internet connections working on 3 locations. All of them behind Airport networks. When connected, "VNC On" appears under the "Current Status" tab in ARD 3.
I'm not sure if I'm connecting via VNC or not. I say this because, VNC has only been initiated remotely via "Change Client Settings" in the Manage Menu. It has NOT been set in the Sharing preferences on the client Mac. So ... is it ON or not??
Or ... am I getting a VNC connection because port 5900 is available and necessary due to it having been opened to accomodate the Airport network ? IOW ... is ARD 3 simply taking the route of least resistance ?
My own questions at this point are ...
1/ Does it matter ?
2/ Is VNC, in my case, less secure than a 'direct' ARD connection?
3/ Is VNC faster or slower than a 'direct' ARD commection?
4/ Are there things that I CANNOT do with VNC that I can do with a 'direct' ARD connection?
5/ Would Ports 22 and 5988 help? (I've seen these mentioned in archived threads).
Grant
(P.S. ... many thanks to those who contribute on this board. I know how frustrating it is trying to communicate this sort of thing to the uninitiated).
AluBook 17