modparam("outbound", "force_outbound_flag", 1) doesn't work. In modules/outbound/ob_mod.c: int use_outbound(struct sip_msg *msg) ... /* If Outbound is forced return success without any further checks */ if (ob_force_flag != -1 && isflagset(msg, ob_force_flag) > 0) isflagset(msg, ob_force_flag) > 0 is always false, it seems the flag is never set. If I remove isflagset(msg, ob_force_flag) > 0, it works, and the token is added in Path header. What's the isflagset() supposed to check ? I'm using the edge proxy example at http://kamailio.org/docs/modules/4.2.x/modules/outbound.html#idp190984 Thanks.