Hello, Kamailio does not handle media on its own (besides rtpengine and other services). If you want to modify the SDP inside your processed SIP messages, the “sdpops” module is one good option. Cheers, Henning -- Henning Westerholt – https://skalatan.de/blog/ Kamailio services – https://gilawa.com *From:* sr-users <sr-users-bounces(a)lists.kamailio.org> *On Behalf Of *Luis Joel Borrego Soto *Sent:* Friday, October 1, 2021 3:06 PM *To:* sr-users(a)lists.kamailio.org *Subject:* [SR-Users] [kamailio/kamailio] SIP Preconditions Settings? Hi Team, According with the RFC3312 (https://datatracker.ietf.org/doc/html/rfc3312 ) The SDP parameters are the following We define the following media level SDP attributes: current-status = "a=curr:" precondition-type SP status-type SP direction-tag desired-status = "a=des:" precondition-type SP strength-tag SP status-type SP direction-tag confirm-status = "a=conf:" precondition-type SP status-type SP direction-tag **precondition-type = "qos" | token strength-tag = ("mandatory" | "optional" | "none" = | "failure" | "unknown")** status-type = ("e2e" | "local" | "remote") direction-tag = ("none" | "send" | "recv" | "sendrecv") Which one should be the equivalent in the Kamailio?, is the a specific module? Br, Joel Borrego (joel.borrego)