kam: do not call rtpengine_manage when not necessary

rtpengine_manage will only be called:

- Requests: BYE/CANCEL + INVITE/UPDATE/ACK with SDP
- Responses: negative to INVITE/UPDATE + positive to INVITE/UPDATE with SDP

Compared with prior logic, these calls will be skipped:

- Requests: INVITE/UPDATE with no SDP.
- Responses: BYE/CANCEL, INVITE/UPDATE positive with no SDP.

Author: cruzccl

kamailio/trunks/config/kamailio.cfg

@@ -2098,8 +2098,13 @@ route[GENERIC_XMLRPC_COMMAND] {
 }
 
 route[RTPENGINE] {
-    if (!is_method("INVITE|UPDATE|ACK|BYE|CANCEL")) return;
-    if (is_method("ACK") && !has_body("application/sdp")) return;
+    # Requests - BYE/CANCEL + INVITE/UPDATE/ACK with SDP
+    if (is_request() && !is_method("INVITE|UPDATE|ACK|BYE|CANCEL")) return;
+    if (is_request() && is_method("INVITE|UPDATE|ACK") && !has_body("application/sdp")) return;
+
+    # Responses - negative responses to INVITE/UPDATE + positive responses to INVITE/UPDATE with SDP
+    if (!is_request() && !is_method("INVITE|UPDATE")) return;
+    if (!is_request() && is_method("INVITE|UPDATE") && t_check_status("[12][0-9]{2}") && !has_body("application/sdp")) return;
 
     if ($(dlg_var(mediaRelaySetsId){s.len}) > 0 && $dlg_var(mediaRelaySetsId) != 0) {
         set_rtpengine_set("$(dlg_var(mediaRelaySetsId){s.int})");

kamailio/users/config/kamailio.cfg

@@ -2661,8 +2661,13 @@ route[GET_CODEC_INFO] {
 }
 
 route[RTPENGINE] {
-    if (!is_method("INVITE|UPDATE|ACK|BYE|CANCEL")) return;
-    if (is_method("ACK") && !has_body("application/sdp")) return;
+    # Requests - BYE/CANCEL + INVITE/UPDATE/ACK with SDP
+    if (is_request() && !is_method("INVITE|UPDATE|ACK|BYE|CANCEL")) return;
+    if (is_request() && is_method("INVITE|UPDATE|ACK") && !has_body("application/sdp")) return;
+
+    # Responses - negative responses to INVITE/UPDATE + positive responses to INVITE/UPDATE with SDP
+    if (!is_request() && !is_method("INVITE|UPDATE")) return;
+    if (!is_request() && is_method("INVITE|UPDATE") && t_check_status("[12][0-9]{2}") && !has_body("application/sdp")) return;
 
     if ($(dlg_var(mediaRelaySetsId){s.len}) > 0 && $dlg_var(mediaRelaySetsId) != 0) {
         xnotice("[$dlg_var(cidhash)] RTPENGINE: MediarelaysetId: $dlg_var(mediaRelaySetsId)\n");