The Teams SIP signaling is set up to use TLS port 5061. For security reasons, the TLS version must be TLS 1.2.
Teams requires the use of the following ECC ciphers:
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Avaya SBC, working with Teams, supports SRTP interworking with RTP/RTCP on the PSTN side and SRTP/SRTCP with a lifetime for the following cryptography suites:
AES_CM_128_HMAC_SHA1_80
AES_CM_128_HMAC_SHA1_32
AES_CM_256_HMAC_SHA1_80
AES_CM_256_HMAC_SHA1_32