FR/FRNET: Introduce simplistic simulation of UEs

Let's start a number of per-UE/TLLI component on each BVC, and generate
some uplink traffic with random-payload 512-byte LLC frames.  The
FRNET(SGSN) side simply ignores all of those by means of a
CreateCallback.

Change-Id: I1b25b4a650d831bb07e9623b76e6c3dcdd71ac88
diff --git a/fr-net/FRNET_Tests.ttcn b/fr-net/FRNET_Tests.ttcn
index 87b9bd7..94b32dc 100644
--- a/fr-net/FRNET_Tests.ttcn
+++ b/fr-net/FRNET_Tests.ttcn
@@ -43,6 +43,11 @@
 	var GbInstances g_gb;
 };
 
+
+private function CreateCallback(BssgpBvci bvci, BssgpCellId cell_id, OCT4 tlli, BssgpDecoded dec) runs on BSSGP_BVC_CT {
+	/* simply ignore any inbound traffic for now */
+}
+
 private function f_init_gb(inout GbInstance gb, charstring id, integer offset) runs on test_CT {
 	var charstring id_idx := id & int2str(offset);
 	gb.vc_NS := NS_CT.create(id_idx & "-NSemu");
@@ -66,7 +71,7 @@
 			cell_id := base + 600 + idx
 		},
 		depth := BSSGP_DECODE_DEPTH_LLC,
-		create_cb := refers(BSSGP_Emulation.DefaultCreateCallback)
+		create_cb := refers(CreateCallback)
 	};
 	return bvc;
 }