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Conceptually Phone Proxy Mode is akin to a Termination Customer Trunk Group where the only signaling method is SIP based registration and the communication protocol is limited to either UDP, TCP, or TLS. To support multiple protocols simple create a Phone Proxy Mode connection Transport Proxy for each protocol that is to be used.
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To disable the Phone Proxy Mode uncheck the icon in the STATUS column for the connection Transport Proxy that should be disabled.