sgsn: TC_attach_*_timeout test cases

Change-Id: If8cd9e4387588e8299b7675b8b57392d7da66bd9
diff --git a/library/L3_Templates.ttcn b/library/L3_Templates.ttcn
index 0d1c229..396a361 100644
--- a/library/L3_Templates.ttcn
+++ b/library/L3_Templates.ttcn
@@ -1408,6 +1408,26 @@
 	}
 }
 
+template PDU_L3_SGSN_MS tr_GMM_ATTACH_REJECT(template OCT1 cause) := {
+	discriminator := '1000'B,
+	tiOrSkip := {
+		skipIndicator := '0000'B
+	},
+	msgs := {
+		gprs_mm := {
+			attachReject := {
+				messageType := '00000100'B,
+				gmmCause := {
+					causeValue := cause
+				},
+				t3302 := *,
+				t3346 := *
+			}
+		}
+	}
+}
+
+
 template (value) PDU_L3_MS_SGSN ts_GMM_ATTACH_COMPL := {
 	discriminator := '0000'B, /* overwritten */
 	tiOrSkip := {