Fixing Connectivity Issues

There are certain states that your network connection can be in that can lead to degraded performance. Listed below are some common connection states, along with suggestions for what you can do to mitigate problems that can arise from them.

TCP

TCP (Transmission Control Protocol) is a reliable, connection-oriented protocol that guarantees data delivery by establishing a connection, checking for errors, and retransmitting lost packets in the correct order. In contrast, UDP (User Datagram Protocol) is a faster, connectionless protocol that sends data without establishing a connection or guaranteeing delivery, making it ideal for calls, where speed matters more than perfect reliability.

Tuple will utilize UDP to transmit audio, video, and screen data whenever it can. However, there are situations where UDP can't be used, so Tuple will fall back to using TCP instead. If you see that a connection is using TCP, there are a few things you can do:

• Check firewall settings: restrictive firewall settings can block UDP traffic. Especially if you're in a corporate environment with restrictive network settings, it's important to ensure that your firewall is correctly configured. You can learn more about configuring your firewall here.
• Switch networks: Certain networks (such as public hotspots, or tethering to your phone) might have restrictions around UDP traffic. If you suspect this is the case, try switching networks.
• Reduce bandwidth usage: TCP's head-of-line blocking mechanism can create significantly degraded performance in cases where there's a lot contention for bandwidth. To mitigate this, you can conserve bandwidth by disabling your webcam, or only sharing a portion of your screen.
• Enable UPnP on your router: if your router supports UPnP (Universal Plug and Play), you can try to use it to automatically allow UDP traffic through. You can learn more about it here.

TURN

TURN (Traversal Using Relays around NAT) is a protocol that uses relay servers to forward traffic between peers when direct peer-to-peer connections fail. Instead of connecting directly to each other, both peers connect to the TURN server, which acts as an intermediary to relay all audio, video, and data between them. Tuple will attempt to use peer-to-peer connections for calls of 3 or fewer; if those fail, it will use TURN as a fallback.

If you see that TURN is being used on a call, you can try the following:

• Check firewall settings: restrictive firewall settings can block peer connections. You can learn more about configuring your firewall here.
• Switch networks: Certain networks (such as public hotspots, or tethering to your phone) might also have restrictions around establishing peer connections. If you suspect this is the case, try switching networks.
• Enable UPnP on your router: if your router supports UPnP (Universal Plug and Play), you can try to use it to automatically allow peer connections. You can learn more about it here.