If Skype is performing badly, or saying ‘The connection speed between you is slow’ or ‘medium’ but you know that both sides of the call have fast internet connections with adequate bandwidth then you may have ran into a problem that we witnessed ourselves recently.
Having already checked the internet bandwidth at both ends using speedtest.net we were sure that Skype should be working fine, as the figures for that showed over 1Mbps upload and 5Mbps download in both cases. But we kept getting error messages from Skype saying the connection has been lost or the ‘speed between you is slow’.
After some analysis the culprit was found to be ZoneAlarm Firewall. Disabling that or putting it into ‘Game mode’ fixed the problem completely the Skype connection went from slow to fast and the video and audio quality was clear and as good as you would normally expect from Skype. This problem could be caused by any firewall or possibly even virus checkers.
So if you are getting poor quality connections within Skype or any other voice or video chat program use this checklist to try & rectify the problem –
1) Test both ends of the connection using speedtest.net then compare your upload/download results with the table below…
Call type Recommended download / upload speed
Voice Calling 100kbps / 100kbps
Video calling /Screen sharing 300kbps / 300kbps
Video calling (high-quality) 500kbps / 500kbps
Video calling (HD) 1.5Mbps / 1.5Mbps
If both ends of the connection meet or exceed the above criteria for the type of connection you are establishing then move on to step 2, otherwise the issue lies with one or both of your internet connections in which case you need to ensure you are not running other applications that may be using your bandwidth, try rebooting your computer and router/modem then test again. Failing all of that, talk to your Internet provider to see if they can help improve your bandwidth speeds.
2) Use Skype’s call quality test tool as shown in the image below. Click the green bar graph icon then click the ‘Test now’ button. It will then tell you your connection speed. It should say fast.

3) If the call connection is still performing badly, try disabling your firewall software. In ZoneAlarm this can be done by right clicking on the system tray icon then entering ‘Game Mode’, or you can disable it altogether by exiting ZoneAlarm. Other Firewall software will have similar options. Once the Firewalls are disabled on both ends of the call, try the connection again. If it now works ok you have a solution, just disable the firewall when you are making Skype calls then re-enable it afterwards. You should also report the problem to the company that makes the firewall software.
4) If the call is still performing badly then you may wish to try some of these other ideas that may improve call quality. Temporarily disable your virus checking software. Try to avoid using wi-fi connections to make the calls if possible. Try to avoid heavily shared networks such as cafes and libraries unless their connections are extremely fast.
5) If the problem persists ask the experts at Skype to see if they can help - https://support.skype.com/