diff -urN asterisk-16.3.0.orig/res/res_pjsip/pjsip_message_filter.c asterisk-16.3.0/res/res_pjsip/pjsip_message_filter.c
--- asterisk-16.5.0/res/res_pjsip/pjsip_message_filter.c	2019-04-04 16:49:57.000000000 +0200
+++ asterisk-16.5.0/res/res_pjsip/pjsip_message_filter.c	2019-06-18 14:46:57.784000000 +0200
@@ -340,6 +340,23 @@
 			}
 		}
 
+		/* set new sdp version */
+		ast_debug(5, "increment SDP version, starting from %x\n",sdp->origin.version);
+		time_t sec;
+		time_t cseqt=1;
+		sec = time(NULL);
+		cseq = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_CSEQ, NULL);
+		if (cseq) {
+		    cseqt=cseq->cseq;
+		    }
+		if (sec + cseqt <= sdp->origin.version) {
+		    /* actual time can be same if sdp is generated more often than once a second */
+		    sdp->origin.version = sec + cseqt + (sdp->origin.version - (sec + cseqt)) + 1;
+		    }
+		else {
+		    sdp->origin.version=sec + cseqt;
+		    }
+
 		pjsip_tx_data_invalidate_msg(tdata);
 	}