1 files changed, 43 insertions, 6 deletions

diff --git a/library/RTP_Emulation.ttcn b/library/RTP_Emulation.ttcn
index 20e4299c..475b4785 100644
--- a/library/RTP_Emulation.ttcn
+++ b/library/RTP_Emulation.ttcn
@@ -188,20 +188,57 @@ function f_rtpem_stats_get(RTPEM_CTRL_PT pt, boolean rtcp := false) return Rtpem
 	return stats;
 }
 
-function f_rtpem_stats_compare(RtpemStats a, RtpemStats b) return boolean {
+function f_rtpem_stats_compare_value(integer a, integer b, integer tolerance := 0) return boolean {
+	var integer temp;
+
+	temp := (a - b)
+	if (temp < 0) {
+		temp := -temp;
+	}
+
+	if (temp > tolerance) {
+		return false;
+	}
+
+	return true;
+}
+
+/* Cross-compare two rtpem-statistics. The transmission statistics on the a side
+ * must match the reception statistics on the other side and vice versa. The
+ * user may also supply a tolerance value (number of packets) when deviations
+ * are acceptable */
+function f_rtpem_stats_compare(RtpemStats a, RtpemStats b, integer tolerance := 0) return boolean {
+	var integer plen;
+
 	log("stats A: ", a);
 	log("stats B: ", b);
+	log("tolerance: ", tolerance, " packets");
 
-	if (a.num_pkts_tx != b.num_pkts_rx or
-	    a.num_pkts_rx != b.num_pkts_tx or
-	    a.bytes_payload_tx != b.bytes_payload_rx or
-	    a.bytes_payload_rx != b.bytes_payload_tx) {
+	if (f_rtpem_stats_compare_value(a.num_pkts_tx, b.num_pkts_rx, tolerance) == false) {
 		return false;
 	}
+
+	if (f_rtpem_stats_compare_value(a.num_pkts_rx, b.num_pkts_tx, tolerance) == false) {
+		return false;
+	}
+
+	if(a.num_pkts_tx > 0) {
+		plen := a.bytes_payload_tx / a.num_pkts_tx;
+	} else {
+		plen := 0;
+	}
+
+	if (f_rtpem_stats_compare_value(a.bytes_payload_tx, b.bytes_payload_rx, tolerance * plen) == false) {
+		return false;
+	}
+
+	if (f_rtpem_stats_compare_value(a.bytes_payload_rx, b.bytes_payload_tx, tolerance * plen) == false) {
+		return false;
+	}
+
 	return true;
 }
 
-
 template PDU_RTP ts_RTP(BIT32_BO_LAST ssrc, INT7b pt, LIN2_BO_LAST seq, uint32_t ts,
 			octetstring payload, BIT1 marker := '0'B) := {
 	version := 2,