Genesys Cloud supports three trunk transport protocols for sending calls with BYOC Cloud. When you configure your BYOC Cloud trunk and select either BYOC Carrier or BYOC PBX as the trunk type, you can select UDP, TCP, or TLS as the trunk transport protocol for sending calls. Furthermore, the trunk transport protocol configuration for BYOC Cloud only controls the protocol used to send calls on the trunk. It is not enforced on calls received on the trunk. Ensure your Carrier or PBX is configured to use the protocol you want.

Note: When choosing a trunk transport protocol, make sure that the appropriate ports on your firewall are open. Common firewall ports for a trunk transport protocol in Genesys Cloud are 5061 for TLS and 5060 for UDP and TCP.
Trunk transport protocol Description
UDP UDP (User Datagram Protocol) is the standard trunk transport protocol. It provides fast, low-latency connections as it uses a continuous packet stream without acknowledge packets (ACK).
TCP If you include large amounts of UUI or custom data in your headers, choose TCP as your trunk transport protocol. Doing so prevents call failures when packets exceed the maximum transmission unit (MTU) of the standard UDP trunk transport protocol.
TLS To ensure that your transactions are secure, choose TLS (Transport Layer Security) as your trunk transport protocol. For more information, see TLS trunk transport protocol specification.
Warning: When you choose a trunk transport protocol, you must configure both ends of the trunk to use the same protocol. If they are not using the same protocol, the trunk may not function.