diff --git a/library/IPA_Types.ttcn b/library/IPA_Types.ttcn
index 1cafd33..517ca47 100644
--- a/library/IPA_Types.ttcn
+++ b/library/IPA_Types.ttcn
@@ -5,7 +5,10 @@
 import from Osmocom_Types all;
 
 type enumerated IpaStreamId {
-	IPAC_PROTO_RSL		(0),
+	IPAC_PROTO_RSL_TRX0	(0),
+	IPAC_PROTO_RSL_TRX1	(1),
+	IPAC_PROTO_RSL_TRX2	(2),
+	IPAC_PROTO_RSL_TRX3	(3),
 	IPAC_PROTO_OSMO		(238),
 	IPAC_PROTO_MGCP_OLD	(252),
 	IPAC_PROTO_SCCP		(253),