Zoom Phone supports secure voice calls for connections between the Zoom Cloud and the Zoom desktop client, mobile app, web browser/client, and supported SIP devices. During call setup, Zoom Phone uses SIP over TLS 1.2 with Advanced Encryption Standard (AES) 256-bit algorithm for these connections. The Zoom desktop client, mobile app, and web browser/client connections encrypt call media to the Zoom Cloud using SRTP with AES 256-bit encryption algorithm. SIP devices configured with SRTP use AES-128 or AES-256 bit algorithm to encrypt call media for connections to the Zoom Cloud, otherwise unencrypted RTP is used as a fallback.
Important: By default, AES-128 bit encryption is enabled for call media transmitted by supported SIP devices. Admins can upgrade devices to AES-256 bit encryption using the web portal. Fax lines may not support full encryption.
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Zoom Phone supports SIP signaling between client and/to server over TLS1.2 with AES-256 bit encryption. Media call is transported and protected by SRTP with AES-256 encryption.
Zoom Phone supports standards-based encryption using SIP over TLS 1.2 Advanced Encryption Standard (AES) 256-bit algorithm for calls and during phone provisioning sessions. In addition, call media is transported and protected by SRTP with AES-128 algorithm for all devices. Zoom Phone admins can upgrade to AES-256 bit encryption for supported devices. Learn more about certified devices.
Admins can upgrade specific models in a site to use AES-256 bit encryption.
If you previously upgraded to AES-256 bit encryption, you can downgrade to AES-128 bit.