diff --git a/main/udptl.c b/main/udptl.c index a0f533fd0cc45bc9fb6c70e88d4427d94b17eb7b..e543b4e8eecebd37983512ac61e34a3048d09d3f 100644 --- a/main/udptl.c +++ b/main/udptl.c @@ -769,6 +769,18 @@ struct ast_frame *ast_udptl_read(struct ast_udptl *udptl) return &ast_null_frame; } + /* + * If early media isn't turned on for the channel driver, it's going to + * drop this frame. By that time though, udptl has already incremented + * the expected sequence number so if the CPE re-sends, the second frame + * will be dropped as a dup even though the first frame never went through. + * So we drop the frame here if the channel isn't up. 'tag' is set by the + * channel drivers on T38_ENABLED or T38_PEER_REINVITE. + */ + if (udptl->tag == NULL) { + return &ast_null_frame; + } + if (udptl->nat) { /* Send to whoever sent to us */ if (ast_sockaddr_cmp(&udptl->them, &addr)) {