sgsn: More comments

Change-Id: Ie64bfc43b2d652f1f556628deb26544217a8286c
diff --git a/sgsn/SGSN_Tests.ttcn b/sgsn/SGSN_Tests.ttcn
index 1652407..eb7fd14 100644
--- a/sgsn/SGSN_Tests.ttcn
+++ b/sgsn/SGSN_Tests.ttcn
@@ -761,25 +761,25 @@
 }
 
 type record PdpActPars {
-	BIT3			tid,
-	BIT4			nsapi,
-	BIT4			sapi,
-	QoSV			qos,
-	PDPAddressV		addr,
-	octetstring		apn optional,
-	ProtocolConfigOptionsV	pco optional,
-	OCT1			exp_rej_cause optional,
-	OCT4			chg_id,
+	BIT3			tid,				/* L3 Transaction ID */
+	BIT4			nsapi,				/* SNDCP NSAPI */
+	BIT4			sapi,				/* LLC SAPI */
+	QoSV			qos,				/* QoS parameters */
+	PDPAddressV		addr,				/* IP address */
+	octetstring		apn optional,			/* APN name */
+	ProtocolConfigOptionsV	pco optional,			/* protoco config opts */
+	OCT1			exp_rej_cause optional,		/* expected SM reject cause */
+	OCT4			chg_id,				/* GTP Charging Identifier */
 
-	OCT4			ggsn_tei_c,
-	OCT4			ggsn_tei_u,
-	octetstring		ggsn_ip_c,
-	octetstring		ggsn_ip_u,
+	OCT4			ggsn_tei_c,			/* GGSN TEI Control*/
+	OCT4			ggsn_tei_u,			/* GGSN TEI User */
+	octetstring		ggsn_ip_c,			/* GGSN IP Control */
+	octetstring		ggsn_ip_u,			/* GGSN IP User */
 
-	OCT4			sgsn_tei_c optional,
-	OCT4			sgsn_tei_u optional,
-	octetstring		sgsn_ip_c optional,
-	octetstring		sgsn_ip_u optional
+	OCT4			sgsn_tei_c optional,		/* SGSN TEI Control */
+	OCT4			sgsn_tei_u optional,		/* SGSN TEI User */
+	octetstring		sgsn_ip_c optional,		/* SGSN IP Control */
+	octetstring		sgsn_ip_u optional		/* SGSN IP USer */
 };
 
 function f_pdp_ctx_act(inout PdpActPars apars) runs on BSSGP_ConnHdlr {