From 64fd02b80d1c054e5c28f0044d7aa5173acbc47f Mon Sep 17 00:00:00 2001
From: Pau Espin Pedrol <pespin@sysmocom.de>
Date: Tue, 21 Dec 2021 18:19:42 +0100
Subject: [PATCH] IuUP_Emulation: Fix frame number wrap-around

As seen when running a test:
IuUP_Emulation.ttcn:150 Dynamic test case error: While RAW-encoding type '@IuUP_Types.IuUP_PDU': There are insufficient bits to encode '@IuUP_Types.IuUP_PDU_Type_0.frame_nr'

Change-Id: Ic9e69115c49545a7b9797d8f85568d5e91dfb329
---
 library/IuUP_Emulation.ttcn | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/library/IuUP_Emulation.ttcn b/library/IuUP_Emulation.ttcn
index 56384ee70..b35602cef 100644
--- a/library/IuUP_Emulation.ttcn
+++ b/library/IuUP_Emulation.ttcn
@@ -143,7 +143,7 @@ function f_IuUP_Em_tx_encap(inout IuUP_Entity st, in octetstring payload) return
 			} else {
 				pdu := valueof(ts_IuUP_Type1(st.tx_next_frame_nr, 0, payload));
 			}
-			st.tx_next_frame_nr := st.tx_next_frame_nr + 1;
+			st.tx_next_frame_nr := (st.tx_next_frame_nr + 1) mod 16;
 		}
 	}
 	if (isvalue(pdu)) {