If you're still unable to connect to an online match, you may want to try the following.
If you are using a wireless connection, please try switching to a wired connection to sustain the connection quality.
Try connecting directly through the modem. This will help identify if there is an issue with the router and/or blocked ports.
Establish a static IP address and port forward. Here are the port numbers your will need Activision Support . If you have any questions on how to port forward, please contact your ISP or the router manufacturer.