Hi all,

We have encountered a challenge while using mbedTLS 3.5.1 and would greatly appreciate the assistance of the experts. Thank you in advance for your support. I used mbedTLS 3.5.1 to connect to the server acc.connect.cpms.milence.com, and the TLS handshake failed with an Alert (Level: Fatal, Description: Protocol Version) error. Detailed information is described at this GitHub issuehttps://github.com/Mbed-TLS/mbedtls/issues/10141.

* We attempted to connect with the Windows EDGE browser and found through packet capture that the handshake was successful. * We were also able to successfully handshake using TLS 1.2. * When we limited the supported group to only: MBEDTLS_SSL_IANA_TLS_GROUP_SECP256R1 and used TLS 1.3, the handshake was also successful. For more details, please refer to the discussion on GitHub: Handshake fail with "Alert (Level: Fatal, Description: Protocol Version)" ・ Issue #10141 ・ Mbed-TLS/mbedtlshttps://github.com/Mbed-TLS/mbedtls/issues/10141.

Best Regards, Fu Baicheng