If you use FaceTime and iMessage behind a firewall

You can use FaceTime and iMessage with most networks. If you're on a network that's behind a firewall, you may need to enable certain ports.

Some networks use firewalls for security. Firewalls block certain Internet traffic from entering or leaving a network. Internet traffic moves through a firewall using ports. To use FaceTime and iMessage behind certain firewalls, you may need to ask your network administrator to enable these ports:

Depending on the NAT configuration of your router and network, additional ports may be used to send and receive video. Some router features, such as port mapping, SIP dropping or dynamic opening of media ports may interfere with FaceTime and iMessage. Contact your network administrator if you need help with port forwarding.

If you're using a Wi-Fi network, learn about recommended settings for Wi-Fi routers and access points.