diff --git a/include/libtcap.h b/include/libtcap.h
index 1e1313a..c55ae06 100644
--- a/include/libtcap.h
+++ b/include/libtcap.h
@@ -3,9 +3,11 @@
 
 
 #include "TCMessage.h"
+#include "Invoke.h"
 
 
 TCMessage_t *tcap_decode(const char *buf, size_t len);
+void *inap_decode(Invoke_t *invoke);
 
 
 #endif
diff --git a/src/tcap.c b/src/tcap.c
index 45ef2ab..417fd3c 100644
--- a/src/tcap.c
+++ b/src/tcap.c
@@ -5,10 +5,20 @@
 #include <sys/types.h>
 
 #include "TCMessage.h"
+#include "Invoke.h"
+#include "InitialDPArg.h"
+#include "ConnectArg.h"
+#include "FurnishChargingInformationArg.h"
 
 
 
 
+#define INVOKE_OPCODE_INITIALDP				0
+#define INVOKE_OPCODE_CONNECT				20
+#define INVOKE_OPCODE_FURNISHCHARGINGINFORMATION	34
+
+
+
 TCMessage_t *tcap_decode(const char *buf, size_t len) {
 	TCMessage_t *ret = NULL;
 	asn_dec_rval_t rv;
@@ -21,3 +31,43 @@ TCMessage_t *tcap_decode(const char *buf, size_t len) {
 	asn_DEF_TCMessage.free_struct(&asn_DEF_TCMessage, ret, 0);
 	return NULL;
 }
+
+void *inap_decode(Invoke_t *invoke) {
+	long opcode;
+	int rv;
+	void *arg = 0;
+
+	if (!invoke || !invoke->parameter)
+		goto nothing;
+
+	if (invoke->opCode.present != OPERATION_PR_localValue)
+		goto nothing;
+
+	if (asn_INTEGER2long(&invoke->opCode.choice.localValue, &opcode))
+		goto nothing;
+
+	switch (opcode) {
+		case INVOKE_OPCODE_INITIALDP:
+			rv = ANY_to_type(invoke->parameter, &asn_DEF_InitialDPArg, &arg);
+			break;
+
+		case INVOKE_OPCODE_CONNECT:
+			rv = ANY_to_type(invoke->parameter, &asn_DEF_ConnectArg, &arg);
+			break;
+
+		case INVOKE_OPCODE_FURNISHCHARGINGINFORMATION:
+			rv = ANY_to_type(invoke->parameter, &asn_DEF_FurnishChargingInformationArg, &arg);
+			break;
+
+		default:
+			goto nothing;
+	}
+
+	if (!rv)
+		return arg;
+
+	/* free struct */
+
+nothing:
+	return NULL;
+}
diff --git a/tests/basic.c b/tests/basic.c
index 030c753..6f017f0 100644
--- a/tests/basic.c
+++ b/tests/basic.c
@@ -1,5 +1,9 @@
 #include <stdio.h>
 #include "libtcap.h"
+#include "ComponentPortion.h"
+#include "Component.h"
+
+
 
 const char tcap[] = "\x64\x81\x86\x49\x03\x0a\x7e\x71\x6b\x2a\x28\x28\x06\x07\x00\x11\x86\x05\x01\x01\x01\xa0\x1d\x61\x1b\xa1\x0d\x06\x0b\x2a\x81\x76\x82\x15\x01\x01\x01\x01\x00\x01\xa2\x03\x02\x01\x00\xa3\x05\xa1\x03\x02\x01\x00\x6c\x53\xa1\x10\x02\x01\x58\x02\x01\x22\xbf\x33\x07\x83\x05\x31\x30\x30\x32\x34\xa1\x3f\x02\x01\x59\x02\x01\x14\x30\x37\xa0\x0e\x04\x0c\x83\x90\x89\x10\x10\x80\x22\x08\x00\x55\x50\x05\x83\x01\x09\x9a\x22\x30\x20\xa0\x1e\x80\x01\x00\x81\x01\x00\x82\x01\x01\x83\x01\x01\x84\x01\x00\x85\x01\x00\x86\x01\x01\x87\x01\x01\x88\x01\x00\x89\x01\x00";
 const int tcap_len = sizeof(tcap) - 1;
@@ -7,10 +11,82 @@ const int tcap_len = sizeof(tcap) - 1;
 
 int main() {
 	TCMessage_t *tcm;
+	ComponentPortion_t *components = 0;
+	Component_t *component;
+	int i;
+	void *arg;
 
 	tcm = tcap_decode(tcap, tcap_len);
 
-	printf("%p\n", tcm);
+	printf("TCMessage: %p\n", tcm);
+
+	switch (tcm->present) {
+		case TCMessage_PR_NOTHING:
+			printf("nothing\n");
+			break;
+
+		case TCMessage_PR_unidirectional:
+			printf("unidirectional\n");
+			components = &tcm->choice.unidirectional.components;
+			break;
+
+		case TCMessage_PR_begin:
+			printf("begin\n");
+			components = tcm->choice.begin.components;
+			break;
+
+		case TCMessage_PR_end:
+			printf("end\n");
+			components = tcm->choice.end.components;
+			break;
+
+		case TCMessage_PR_continue:
+			printf("continue\n");
+			components = tcm->choice.Continue.components;
+			break;
+
+		case TCMessage_PR_abort:
+			printf("abort\n");
+			break;
+	}
+
+	if (components) {
+		printf("%i components\n", components->list.count);
+
+		for (i = 0; i < components->list.count; i++) {
+			printf("Component #%i\n", i);
+
+			component = components->list.array[i];
+
+			switch (component->present) {
+				case Component_PR_NOTHING:
+					printf("nothing\n");
+					break;
+
+				case Component_PR_invoke:
+					printf("invoke\n");
+					arg = inap_decode(&component->choice.invoke);
+					printf("arg: %p\n", arg);
+					break;
+
+				case Component_PR_returnResultLast:
+					printf("returnResultLast\n");
+					break;
+
+				case Component_PR_returnError:
+					printf("returnError\n");
+					break;
+
+				case Component_PR_reject:
+					printf("reject\n");
+					break;
+
+				case Component_PR_returnResultNotLast:
+					printf("returnResultNotLast\n");
+					break;
+			}
+		}
+	}
 
 	return 0;
 }