diff --git a/library/IPA_Types.ttcn b/library/IPA_Types.ttcn
new file mode 100644
index 0000000..ceb31ce
--- /dev/null
+++ b/library/IPA_Types.ttcn
@@ -0,0 +1,31 @@
+/* (C) 2017 by Harald Welte <laforge@gnumonks.org> */
+
+module IPA_Types {
+
+import from Osmocom_Types all;
+
+type uint8_t IpaStreamId;
+
+external function enc_PDU_IPA(in PDU_IPA pdu) return octetstring
+with { extension "prototype(convert)"
+       extension "encode(RAW)"
+     }
+
+external function dec_PDU_IPA(in octetstring stream) return PDU_IPA
+with { extension "prototype(convert)"
+       extension "decode(RAW)"
+     }
+
+type record PDU_IPA
+{
+	uint16_t	lengthInd,
+	IpaStreamId	streamId,
+	octetstring	payloadData
+} with {
+	variant (lengthInd) "LENGTHTO(lengthInd,streamId,payloadData)";
+	variant (lengthInd) "FIELDLENGTH(16)";
+	variant (lengthInd) "BYTEORDER(last)";
+	encode "RAW";
+}
+
+}