diff --git a/library/OPCAP_Templates.ttcn b/library/OPCAP_Templates.ttcn
new file mode 100644
index 0000000..0a1c884
--- /dev/null
+++ b/library/OPCAP_Templates.ttcn
@@ -0,0 +1,54 @@
+module OPCAP_Templates {
+
+/* OPCAP_Templates, defining TTCN-3 templates for the osmo-pcap protocol.
+ *
+ * OPCAP is a non-standard protocol used between osmo-pcap-client and osmo-pcap-server.
+ *
+ * (C) 2021 by Harald Welte <laforge@gnumonks.org>
+ * All rights reserved.
+ *
+ * Released under the terms of GNU General Public License, Version 2 or
+ * (at your option) any later version.
+ */
+
+import from General_Types all;
+import from Osmocom_Types all;
+import from OPCAP_Types all;
+
+
+template (present) OPCAP_PDU tr_OPCAP_FILE_HDR(template (present) uint32_t linktype := ?) := {
+	msg_type := PKT_LINK_HDR,
+	spare := ?,
+	len := 24,
+	u := {
+		file := {
+			magic := PCAP_MAGIC,
+			version_major := PCAP_VERSION_MAJOR,
+			version_minor := PCAP_VERSION_MINOR,
+			thiszone := 0,
+			sigfigs := 0,
+			snaplen := 9000,
+			linktype := linktype
+		}
+	}
+}
+
+template (present) OPCAP_PDU tr_OPCAP_PKT(template (present) octetstring payload,
+					  template (present) uint32_t caplen := ?,
+					  template (present) uint32_t len := ?) := {
+	msg_type := PKT_LINK_DATA,
+	spare := ?,
+	len := ?,
+	u := {
+		packet := {
+			ts_sec := ?,
+			ts_usec := ?,
+			caplen := caplen,
+			len := len,
+			payload := payload
+		}
+	}
+}
+
+
+};