1) Audio Issues

Low call volume, background noise and feedback are some of the problems you might typically run into.You can avoid most of these by using a headset (luckily now also available in better-looking behind-the-head designs, but if you don’t happen to have one handy, try these tips:

Volume

iChat tries to automatically optimize the call’s volume, but you can increase the overall volume of the call in the “Sound” section of your System Preferences. Under the “Input” options, drag the volume slider to your preferred level and also check “Use ambient noise reduction”, to minimize background noise.

Feedback loops

To prevent feedback, try lowering your volume, or either use external speakers and keep them pointed away from your Mac’s microphone. Alternatively use headphones along with the internal microphone.

2) Connection issues

Port forwarding

If you receiving a lot of connection issues whilst trying to a new video chat, try activating Port Forwarding on your router. Whilst not strictly necessary, it seems to make connecting more reliable in my experience. iChat uses the following ports: 

5060, 5353, 5678, 16393-16402 (UDP) and 5190, 5297, 5298 (UPD & TCP).

If you’re unsure how to configure Port Forwarding on your router, head over to the handy PortForward.com website, select your Router’s brand and model and then select “iChat” as your application for full instructions.

Audio or video keeps breaking up 

iChat adjust the AV quality depending on the available bandwidth. However this can sometimes cause jerky video or choppy audio if the available bandwidth fluctuates.

To fix this, open iChat’s Connection Doctor from the “Video” menu and select “Statistics” from the drop down menu. Monitor the bandwidth values and make a note of the general average. Then head over to iChat’s Preferences (iChat > Preferences) and select the “Audio / Video” tab.

There you can specify a bandwidth limit. Select the value just under the average you made a note of above. That will force iChat to reduce the overall quality of the call slightly, but the quality should be more consistent. 

3) Auto-Accept calls

If you don’t want to have to dash to your computer every time you receive a new call, you can also get iChat to automatically accept all incoming calls.

Go to the “Events” in iChat’s preferences and select “Video Invitation” from the “Events” list. Then check the “Run Applescript” box and choose “Auto Accept.applescript” from the list. 

(Note: If you only want to auto-accept calls from certain contacts check out the free iChat utility, Chax).

iChat is a great tool for keeping in touch, so I hope these tips can help make it even better for you guys!