diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index bf7e839..9c2e74a 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -1049,6 +1049,25 @@
 	vc_conn.done;
 }
 
+/* IPA CRCX on SDCCH/4 and SDCCH/8 (doesn't make sense) */
+function f_TC_ipa_crcx_sdcch_not_active(charstring id) runs on ConnHdlr {
+	f_rsl_transceive(ts_RSL_IPA_CRCX(g_chan_nr), tr_RSL_IPA_CRCX_NACK(g_chan_nr, ?),
+			 "IPA CRCX NACK");
+}
+testcase TC_ipa_crcx_sdcch_not_active() runs on test_CT {
+	var ConnHdlrPars pars;
+	var ConnHdlr vc_conn;
+	f_init(testcasename());
+
+	pars := valueof(t_Pars(t_RslChanNr_SDCCH4(0,1), ts_RSL_ChanMode_SIGN));
+	vc_conn := f_start_handler(refers(f_TC_ipa_crcx_sdcch_not_active), pars);
+	vc_conn.done;
+
+	pars := valueof(t_Pars(t_RslChanNr_SDCCH8(6,5), ts_RSL_ChanMode_SIGN));
+	vc_conn := f_start_handler(refers(f_TC_ipa_crcx_sdcch_not_active), pars);
+	vc_conn.done;
+}
+
 
 /* TODO Areas:
 
@@ -1103,6 +1122,7 @@
 	execute( TC_ipa_dlcx_not_active() );
 	execute( TC_ipa_crcx_twice_not_active() );
 	execute( TC_ipa_crcx_mdcx_dlcx_not_active() );
+	execute( TC_ipa_crcx_sdcch_not_active() );
 }
 
 
diff --git a/library/RSL_Types.ttcn b/library/RSL_Types.ttcn
index 1d68969..3c2db73 100644
--- a/library/RSL_Types.ttcn
+++ b/library/RSL_Types.ttcn
@@ -475,6 +475,10 @@
 		RSL_ERR_SERV_OPT_UNIMPL		('4f'O),
 		/* invalid message */
 		RSL_ERR_RCH_ALR_ACTV_ALLOC	('50'O),
+		RSL_ERR_IPA_RCH_NOT_ACTV_ALLOC	('51'O),
+		RSL_ERR_IPA_CONN_INVALID	('52'O),
+		RSL_ERR_IPA_CONN_IN_USE		('53'O),
+		RSL_ERR_IPA_CONN_ALREADY_EXISTS	('54'O),
 		RSL_ERR_INVALID_MESSAGE		('5f'O),
 		/* protocol error */
 		RSL_ERR_MSG_DISCR		('60'O),