Communication Error (-8).....WHAT IN THE HECK IS GOING ON???

Question

One night i was talking to my friend, Phil, (who also has a macbook) perfectly on iChat AV and it was wonderful. The next night i tried again and it wouldn't work with him or my non-macbook friend, Danielle, but only with a different macbook friend, Cheryl. Now I can't connect with anyone outside of my network. I have only been able to connect to my friend David (I give names so that you ar able to differentiate between who is who). However, David is currently living in my house and is therefore in my network so of course i am able to video chat with him.
Everytime i try i get the same "communication error -8". I have tried various solutions i've found in the forums, but nothing seems to help at all. I've also noticed that A LOT of people are having this same problem and am wondering if perhaps it is a manufacturing error that started at the beginning in the factory when it was being made, but i'm probably wrong about that.
Can anyone tell me if they no the solution to this problem?? HELP!!!!!!!!

Answer 1

Please remember you gave me permission to do this.
Ok most routers or modems have certain ports open so that it works out of the box for Web Browsing and Mail applications.
These ports are sort of virtual and inside the device. Your computer also has them.
So Web browsing happens on port 80 that you may have heard of. Mail can be on several for in and out purposes and for the different types of Mail accounts you can have (POP or IMAP) (port 25, 110, 995 or even 443)
Now there are in fact 65535 of these ports. So other applications and certain different internet protocols use these ports. On line games is one reason. These can use multiple ports for one game.
Now from there routers and modems need the ports above a certain threshold to be opened when you want to use them.
This threshold is port 1024.
Now how these ports are opened on different devices can vary.
Port Forward (or a variation name like Virtual Servers or Pinholes) is the oldest and most common.
This allows you to point one port (or sometime s a range) to a corresponding port(s) on your computer.
An example would be to point port 1024 to port 1024 on your Computer.
This method would only allow this to one IP (your computer) on the LAN.
(Hence the original question - Are you doing this ?)
There is normally a table if you need to open more ports for one Application
Next comes DMZ (Demiltarized Zone) This is a means of opening all the ports to One IP (Computer) Not considered secure, but useful for testing. Consider it an extreme form of Port Forwarding.
Next come Port Triggering.
This uses One port up front so to speak that then openes other ports. It has the advantage that multiple computers can use the ports at the same time.
Then comes UPnP (Universal Plug n Play) This gives control to the applications to open the ports when they need them. (they close after a timed period of Non use).
Again multiple computers can use the same ports at the same time.
Not all routers or modems that route have all methods although some do.
Then we come on to iChat.
This uses 29 ports (for AIM Login, File sending, Text chats, A/V chats, the Jabber side and the Bonjour side) over two protocols (total of 31 entries in some cases)
These ports are above the 1024 threshold and some are particular as Apple has said iChat is a VoIP application.
Most devices that route can be controlled by yourself and have default ways to access their set up pages via a web browser.
This will involve an IP typed into the web browser which will bring up a Pop Up asking for a User ID and (Or at least ) a password.
This site http://portforward.com/routers.htm list many devices.
Clicking on yours and then iChat in the next page will take you to a device and application specific page.
It is obviously then goes on about Port Forwarding settings.
However the pages are useful for the default access info.
Once you have gained access it is a question of checking the menus to see it does UPnP. ( It is a one stop enable/disable setting and allows multiple computers)
Consider a router without the ports open as a hardware firewall.
It may allow outgoing stuff giving you intermittent looking results.
If you tell us which device you have then we can point you to a more specific solution.
Networking in general.
Most of these devices do what is called DHCP. It is not so important about what the name means other than it means the device gives out IP numbers (Addresses) to your computers.
However it is not good networking to have two devices doing DHCP.
There is more on this subject but that is enough for now.
8:17 PM Wednesday; August 22, 2007