diff --git a/lib/diameter.py b/lib/diameter.py
index 12c45c4..f313edc 100755
--- a/lib/diameter.py
+++ b/lib/diameter.py
@@ -1735,6 +1735,9 @@ def Answer_16777251_318(self, packet_vars, avps):
         except ValueError as e:
             self.logTool.log(service='HSS', level='debug', message="Error getting subscriber details for IMSI " + str(imsi), redisClient=self.redisMessaging)
             self.logTool.log(service='HSS', level='debug', message=e, redisClient=self.redisMessaging)
+            decodedPlmn = self.DecodePLMN(plmn=plmn)
+            mcc = decodedPlmn[0]
+            mnc = decodedPlmn[1]
             self.redisMessaging.sendMetric(serviceName='diameter', metricName='prom_diam_auth_event_count',
                                             metricType='counter', metricAction='inc', 
                                             metricValue=1.0, 
@@ -1746,7 +1749,7 @@ def Answer_16777251_318(self, packet_vars, avps):
                                             metricInflux={
                                                             "measurement": "S6a_Authentication_Information_Request",
                                                             "fields": {"Result-Code": 5001},
-                                                            "tags": {"IMSI": str(imsi)},
+                                                            "tags": {"IMSI": str(imsi), "MCC": str(mcc), "MNC": str(mnc)},
                                                             "time": datetime.datetime.now(datetime.timezone.utc).astimezone().isoformat()
                                                         },
                                             metricHelp='Diameter Authentication related Counters',