diff --git a/configs/csfb.yaml.in b/configs/csfb.yaml.in
index 48e7584b7..53c2c5457 100644
--- a/configs/csfb.yaml.in
+++ b/configs/csfb.yaml.in
@@ -47,12 +47,12 @@ mme:
         map:
           tai:
             plmn_id:
-              mcc: 901
+              mcc: 999
               mnc: 70
             tac: 7
           lai:
             plmn_id:
-              mcc: 901
+              mcc: 999
               mnc: 70
             lac: 2342
         map:
@@ -68,7 +68,7 @@ mme:
             lac: 51544
     gummei:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         mme_gid: 2
         mme_code: 1
@@ -79,7 +79,7 @@ mme:
         mme_code: 1
     tai:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       tac: 7
     tai:
@@ -146,19 +146,19 @@ amf:
       - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         amf_id:
           region: 2
           set: 1
     tai:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         tac: 1
     plmn_support:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         s_nssai:
           - sst: 1
diff --git a/configs/non3gpp.yaml.in b/configs/non3gpp.yaml.in
index 251ecdb69..36882612a 100644
--- a/configs/non3gpp.yaml.in
+++ b/configs/non3gpp.yaml.in
@@ -44,13 +44,13 @@ mme:
       - addr: 127.0.0.2
     gummei:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       mme_gid: 2
       mme_code: 1
     tai:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       tac: 1
     security:
@@ -114,19 +114,19 @@ amf:
       - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         amf_id:
           region: 2
           set: 1
     tai:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         tac: 1
     plmn_support:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         s_nssai:
           - sst: 1
diff --git a/configs/open5gs/amf.yaml.in b/configs/open5gs/amf.yaml.in
index 779440451..c5b8de8d4 100644
--- a/configs/open5gs/amf.yaml.in
+++ b/configs/open5gs/amf.yaml.in
@@ -150,7 +150,7 @@ logger:
 #  o Multiple GUAMI
 #    guami:
 #      - plmn_id:
-#          mcc: 901
+#          mcc: 999
 #          mnc: 70
 #        amf_id:
 #          region: 2
@@ -199,13 +199,13 @@ logger:
 #  o Multiple PLMN Support
 #    plmn_support:
 #      - plmn_id:
-#          mcc: 901
+#          mcc: 999
 #          mnc: 70
 #        s_nssai:
 #          - sst: 1
 #            sd: 010000
 #      - plmn_id:
-#          mcc: 901
+#          mcc: 999
 #          mnc: 70
 #        s_nssai:
 #          - sst: 1
@@ -218,7 +218,7 @@ logger:
 #
 #  <AMF Name>
 #
-#    amf_name: amf1.open5gs.amf.5gc.mnc70.mcc901.3gppnetwork.org
+#    amf_name: amf1.open5gs.amf.5gc.mnc70.mcc999.3gppnetwork.org
 #
 #  <Relative Capacity> - Default(255)
 #
@@ -232,19 +232,19 @@ amf:
       - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         amf_id:
           region: 2
           set: 1
     tai:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         tac: 1
     plmn_support:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         s_nssai:
           - sst: 1
diff --git a/configs/open5gs/mme.yaml.in b/configs/open5gs/mme.yaml.in
index 469151be3..12bda8540 100644
--- a/configs/open5gs/mme.yaml.in
+++ b/configs/open5gs/mme.yaml.in
@@ -250,13 +250,13 @@ mme:
       - addr: 127.0.0.2
     gummei:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       mme_gid: 2
       mme_code: 1
     tai:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       tac: 1
     security:
diff --git a/configs/open5gs/smf.yaml.in b/configs/open5gs/smf.yaml.in
index 1448defdd..4148021e6 100644
--- a/configs/open5gs/smf.yaml.in
+++ b/configs/open5gs/smf.yaml.in
@@ -269,7 +269,7 @@ logger:
 #              - internet
 #              - ims
 #
-#  o S-NSSAI[SST:1] and DNN[internet] and TAI[PLMN-ID:90170 TAC:1]
+#  o S-NSSAI[SST:1] and DNN[internet] and TAI[PLMN-ID:99970 TAC:1]
 #    info:
 #      - s_nssai:
 #          - sst: 1
@@ -277,14 +277,14 @@ logger:
 #              - internet
 #        tai:
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            tac: 1
 #
 #  o If any of conditions below are met:
-#   - S-NSSAI[SST:1] and DNN[internet] and TAI[PLMN-ID:90170 TAC:1-9]
+#   - S-NSSAI[SST:1] and DNN[internet] and TAI[PLMN-ID:99970 TAC:1-9]
 #   - S-NSSAI[SST:2 SD:000080] and DNN[internet or ims]
-#   - S-NSSAI[SST:4] and DNN[internet] and TAI[PLMN-ID:90170 TAC:10-20,30-40]
+#   - S-NSSAI[SST:4] and DNN[internet] and TAI[PLMN-ID:99970 TAC:10-20,30-40]
 #
 #    info:
 #      - s_nssai:
@@ -293,7 +293,7 @@ logger:
 #              - internet
 #        tai:
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            range:
 #              - 1-9
@@ -309,7 +309,7 @@ logger:
 #              - internet
 #        tai:
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            range:
 #              - 10-20
@@ -339,27 +339,27 @@ logger:
 #              - internet
 #        tai:
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            tac: [1, 2, 3]
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            tac: 4
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            tac:
 #              - 5
 #              - 6
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            range:
 #              - 100-200
 #              - 300-400
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            range:
 #              - 500-600
@@ -371,7 +371,7 @@ logger:
 #              - internet
 #        tai:
 #          - plmn_id:
-#              mcc: 901
+#              mcc: 999
 #              mnc: 70
 #            tac: 99
 #
diff --git a/configs/sample.yaml.in b/configs/sample.yaml.in
index a1e1e051f..e9efe8e01 100644
--- a/configs/sample.yaml.in
+++ b/configs/sample.yaml.in
@@ -44,13 +44,13 @@ mme:
       - addr: 127.0.0.2
     gummei:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       mme_gid: 2
       mme_code: 1
     tai:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       tac: 1
     security:
@@ -112,19 +112,19 @@ amf:
       - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         amf_id:
           region: 2
           set: 1
     tai:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         tac: 1
     plmn_support:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         s_nssai:
           - sst: 1
diff --git a/configs/slice.yaml.in b/configs/slice.yaml.in
index 1845f7ec2..d48f77908 100644
--- a/configs/slice.yaml.in
+++ b/configs/slice.yaml.in
@@ -44,13 +44,13 @@ mme:
       - addr: 127.0.0.2
     gummei:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       mme_gid: 2
       mme_code: 1
     tai:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       tac: 1
     security:
@@ -112,19 +112,19 @@ amf:
       - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         amf_id:
           region: 202
           set: 1016
     tai:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         tac: 1
     plmn_support:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         s_nssai:
           - sst: 1
diff --git a/configs/srslte.yaml.in b/configs/srslte.yaml.in
index 62ad6021b..f18bc3ca0 100644
--- a/configs/srslte.yaml.in
+++ b/configs/srslte.yaml.in
@@ -44,13 +44,13 @@ mme:
       - addr: 127.0.0.2
     gummei:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       mme_gid: 2
       mme_code: 1
     tai:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       tac: 7
     security:
@@ -112,19 +112,19 @@ amf:
       - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         amf_id:
           region: 2
           set: 1
     tai:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         tac: 1
     plmn_support:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         s_nssai:
           - sst: 1
diff --git a/configs/volte.yaml.in b/configs/volte.yaml.in
index eb26d7ef0..37f9de6c2 100644
--- a/configs/volte.yaml.in
+++ b/configs/volte.yaml.in
@@ -44,13 +44,13 @@ mme:
       - addr: 127.0.0.2
     gummei:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       mme_gid: 2
       mme_code: 1
     tai:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       tac: 1
     security:
@@ -115,19 +115,19 @@ amf:
       - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         amf_id:
           region: 2
           set: 1
     tai:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         tac: 1
     plmn_support:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         s_nssai:
           - sst: 1
diff --git a/configs/vonr.yaml.in b/configs/vonr.yaml.in
index 9bae3e80c..616bbd72f 100644
--- a/configs/vonr.yaml.in
+++ b/configs/vonr.yaml.in
@@ -44,13 +44,13 @@ mme:
       - addr: 127.0.0.2
     gummei:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       mme_gid: 2
       mme_code: 1
     tai:
       plmn_id:
-        mcc: 901
+        mcc: 999
         mnc: 70
       tac: 1
     security:
@@ -115,19 +115,19 @@ amf:
       - addr: 127.0.0.5
     guami:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         amf_id:
           region: 2
           set: 1
     tai:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         tac: 1
     plmn_support:
       - plmn_id:
-          mcc: 901
+          mcc: 999
           mnc: 70
         s_nssai:
           - sst: 1
diff --git a/docs/_docs/guide/01-quickstart.md b/docs/_docs/guide/01-quickstart.md
index 9d13a4261..6dbcaa279 100644
--- a/docs/_docs/guide/01-quickstart.md
+++ b/docs/_docs/guide/01-quickstart.md
@@ -249,7 +249,7 @@ $ diff -u /etc/open5gs/mme.yaml.old /etc/open5gs/mme.yaml
        addr: 127.0.0.2
      gummei:
        plmn_id:
--        mcc: 901
+-        mcc: 999
 -        mnc: 70
 +        mcc: 001 # set your PLMN-MCC
 +        mnc: 01  # set your PLMN-MNC
@@ -257,7 +257,7 @@ $ diff -u /etc/open5gs/mme.yaml.old /etc/open5gs/mme.yaml
        mme_code: 1
      tai:
        plmn_id:
--        mcc: 901
+-        mcc: 999
 -        mnc: 70
 -      tac: 1
 +        mcc: 001 # set your PLMN-MCC
@@ -308,7 +308,7 @@ amf:
 +      - addr: 10.10.0.5 # for external gNB - a local address that can be reached by the gNB
      guami:
        - plmn_id:
--          mcc: 901
+-          mcc: 999
 -          mnc: 70
 +          mcc: 001 # set your PLMN-MCC
 +          mnc: 01  # set your PLMN-MNC
@@ -317,7 +317,7 @@ amf:
            set: 1
      tai:
        - plmn_id:
--          mcc: 901
+-          mcc: 999
 -          mnc: 70
 -        tac: 1
 +          mcc: 001 # set your PLMN-MCC
@@ -325,7 +325,7 @@ amf:
 +        tac: 2 # should match the TAC used by your gNB
      plmn_support:
        - plmn_id:
--          mcc: 901
+-          mcc: 999
 -          mnc: 70
 +          mcc: 001 # set your PLMN-MCC
 +          mnc: 01  # set your PLMN-MNC
diff --git a/docs/_docs/guide/02-building-open5gs-from-sources.md b/docs/_docs/guide/02-building-open5gs-from-sources.md
index 49e1bc3dd..3e475e8ea 100644
--- a/docs/_docs/guide/02-building-open5gs-from-sources.md
+++ b/docs/_docs/guide/02-building-open5gs-from-sources.md
@@ -107,7 +107,7 @@ $ diff -u /etc/open5gs/amf.yaml.old /etc/open5gs/amf.yaml
 +      - addr: 10.10.0.5
      guami:
        - plmn_id:
--          mcc: 901
+-          mcc: 999
 -          mnc: 70
 +          mcc: 001
 +          mnc: 01
@@ -116,7 +116,7 @@ $ diff -u /etc/open5gs/amf.yaml.old /etc/open5gs/amf.yaml
            set: 1
      tai:
        - plmn_id:
--          mcc: 901
+-          mcc: 999
 -          mnc: 70
 -        tac: 1
 +          mcc: 001
@@ -124,7 +124,7 @@ $ diff -u /etc/open5gs/amf.yaml.old /etc/open5gs/amf.yaml
 +        tac: 2
      plmn_support:
        - plmn_id:
--          mcc: 901
+-          mcc: 999
 -          mnc: 70
 +          mcc: 001
 +          mnc: 01
@@ -168,7 +168,7 @@ $ diff -u /etc/open5gs/mme.yaml.old /etc/open5gs/mme.yaml
        addr: 127.0.0.2
      gummei:
        plmn_id:
--        mcc: 901
+-        mcc: 999
 -        mnc: 70
 +        mcc: 001
 +        mnc: 01
@@ -176,7 +176,7 @@ $ diff -u /etc/open5gs/mme.yaml.old /etc/open5gs/mme.yaml
        mme_code: 1
      tai:
        plmn_id:
--        mcc: 901
+-        mcc: 999
 -        mnc: 70
 -      tac: 1
 +        mcc: 001
diff --git a/docs/_docs/guide/03-splitting-network-functions.md b/docs/_docs/guide/03-splitting-network-functions.md
index c8f3c9e96..52c1f1970 100644
--- a/docs/_docs/guide/03-splitting-network-functions.md
+++ b/docs/_docs/guide/03-splitting-network-functions.md
@@ -70,7 +70,7 @@ $ diff -u /etc/open5gs/mme.yaml.old /etc/open5gs/mme.yaml
        plmn_id:
 -        mcc: 001
 -        mnc: 01
-+        mcc: 901
++        mcc: 999
 +        mnc: 70
        mme_gid: 2
        mme_code: 1
@@ -79,7 +79,7 @@ $ diff -u /etc/open5gs/mme.yaml.old /etc/open5gs/mme.yaml
 -        mcc: 001
 -        mnc: 01
 -      tac: 7
-+        mcc: 901
++        mcc: 999
 +        mnc: 70
 +      tac: 1
      security:
@@ -153,7 +153,7 @@ diff -u /etc/open5gs/amf.yaml.old /etc/open5gs/amf.yaml
        - plmn_id:
 -          mcc: 001
 -          mnc: 01
-+          mcc: 901
++          mcc: 999
 +          mnc: 70
          amf_id:
            region: 2
@@ -163,14 +163,14 @@ diff -u /etc/open5gs/amf.yaml.old /etc/open5gs/amf.yaml
 -          mcc: 001
 -          mnc: 01
 -        tac: 7
-+          mcc: 901
++          mcc: 999
 +          mnc: 70
 +        tac: 1
      plmn_support:
        - plmn_id:
 -          mcc: 001
 -          mnc: 01
-+          mcc: 901
++          mcc: 999
 +          mnc: 70
          s_nssai:
            - sst: 1
diff --git a/docs/_docs/troubleshoot/02-now-in-github-issues.md b/docs/_docs/troubleshoot/02-now-in-github-issues.md
index 45621edd2..9955431bf 100644
--- a/docs/_docs/troubleshoot/02-now-in-github-issues.md
+++ b/docs/_docs/troubleshoot/02-now-in-github-issues.md
@@ -97,7 +97,7 @@ $ mongo
 > db.subscribers.find().pretty()
 {
 	"_id" : ObjectId("60969fe79459f8b40d8d3f68"),
-	"imsi" : "901700000000001",
+	"imsi" : "999700000000001",
 	"__v" : 0,
 	"access_restriction_data" : 32,
 	"ambr" : {
@@ -164,7 +164,7 @@ $ mongo
 > db.subscribers.find().pretty()
 {
 	"_id" : ObjectId("609715fda08851a0744e6ae7"),
-	"imsi" : "901700000021309",
+	"imsi" : "999700000021309",
 	"__v" : 0,
 	"access_restriction_data" : 32,
 	"ambr" : {
@@ -317,7 +317,7 @@ index 7e939e81..dfe4456d 100644
          s_nssai:
            - sst: 1
 +      - plmn_id:
-+          mcc: 901
++          mcc: 999
 +          mnc: 70
 +        s_nssai:
 +          - sst: 1
@@ -1089,12 +1089,12 @@ Currently, the number of UE is limited to `128*128`.
 
 ```
 * AMF_ID
-  PLMN ID - MNC: 901, MCC: 70
+  PLMN ID - MNC: 999, MCC: 70
   Region : 2
   Set : 1
 
 * TAI
-  PLMN ID - MNC: 901, MCC: 70
+  PLMN ID - MNC: 999, MCC: 70
   TAC : 1
 
 * S_NSSASI
@@ -1105,12 +1105,12 @@ Currently, the number of UE is limited to `128*128`.
 
 ```
 * GUMMEI
-  PLMN ID - MNC: 901, MCC: 70
+  PLMN ID - MNC: 999, MCC: 70
   MME Group : 2
   MME Code : 1
 
 * TAI
-  PLMN ID - MNC: 901, MCC: 70
+  PLMN ID - MNC: 999, MCC: 70
   TAC : 1
 ```
 
diff --git a/docs/_docs/tutorial/01-your-first-lte.md b/docs/_docs/tutorial/01-your-first-lte.md
index 478e8b948..bdc7e7dc6 100644
--- a/docs/_docs/tutorial/01-your-first-lte.md
+++ b/docs/_docs/tutorial/01-your-first-lte.md
@@ -190,14 +190,14 @@ Title : sysmocom SIM Card Details / AM93\PICK\00859
 
 IMSI    ICCID   ACC PIN1    PUK1    PIN2    PUK2    Ki  OPC ADM1    KIC1    KID1    KIK1
 ...
-901700000017408	8988211000000174089	0100	3623	84724035	8774	57473966	B1233463AB9BC2AD2DB1830EB6417E7B	625150E2A943E3353DD23554101CAFD4	47190711	C865CAA0A54542333929B29B116F4375	7D7F65DCD99003C0A0D5D31CA3E5253E	5B27983AF628FC3FCB36B89300012944
+999700000017408	8988211000000174089	0100	3623	84724035	8774	57473966	B1233463AB9BC2AD2DB1830EB6417E7B	625150E2A943E3353DD23554101CAFD4	47190711	C865CAA0A54542333929B29B116F4375	7D7F65DCD99003C0A0D5D31CA3E5253E	5B27983AF628FC3FCB36B89300012944
 ```
 
 Here's my subscriber information from above.
 
 ```
-MCC/MNC : 901/70
-IMSI : 901700000017408
+MCC/MNC : 999/70
+IMSI : 999700000017408
 K : B1233463AB9BC2AD2DB1830EB6417E7B
 OPc : 625150E2A943E3353DD23554101CAFD4  
 ```
@@ -238,7 +238,7 @@ $ diff -u /etc/open5gs/mme.yaml.old /etc/open5gs/mme.yaml
        addr: 127.0.0.2
      gummei:
        plmn_id:
--        mcc: 901
+-        mcc: 999
 -        mnc: 70
 +        mcc: 310
 +        mnc: 789
@@ -246,7 +246,7 @@ $ diff -u /etc/open5gs/mme.yaml.old /etc/open5gs/mme.yaml
        mme_code: 1
      tai:
        plmn_id:
--        mcc: 901
+-        mcc: 999
 -        mnc: 70
 -      tac: 1
 +        mcc: 310
diff --git a/src/mme/nas-path.c b/src/mme/nas-path.c
index 67b616b64..ee499c1aa 100644
--- a/src/mme/nas-path.c
+++ b/src/mme/nas-path.c
@@ -134,7 +134,7 @@ int nas_eps_send_attach_reject(mme_ue_t *mme_ue,
     mme_sess_t *sess = NULL;
     ogs_pkbuf_t *esmbuf = NULL, *emmbuf = NULL;
 
-    ogs_assert(mme_ue);
+    ogs_expect_or_return_val(mme_ue, OGS_ERROR);
 
     ogs_debug("[%s] Attach reject", mme_ue->imsi_bcd);
     ogs_debug("    Cause[%d]", emm_cause);
diff --git a/src/mme/sgsap-handler.c b/src/mme/sgsap-handler.c
index 41a8ca254..f8d3686d9 100644
--- a/src/mme/sgsap-handler.c
+++ b/src/mme/sgsap-handler.c
@@ -48,8 +48,10 @@ void sgsap_handle_location_update_accept(mme_vlr_t *vlr, ogs_pkbuf_t *pkbuf)
     ogs_pkbuf_pull(pkbuf, 1);
 
     root = ogs_tlv_parse_block(pkbuf->len, pkbuf->data, OGS_TLV_MODE_T1_L1);
-    if (!root)
+    if (!root) {
+        ogs_error("!root");
         goto error;
+    }
 
     iter = root;
     while (iter) {
@@ -73,20 +75,29 @@ void sgsap_handle_location_update_accept(mme_vlr_t *vlr, ogs_pkbuf_t *pkbuf)
 
     ogs_tlv_free_all(root);
 
-    if (!nas_mobile_identity_imsi || !lai)
+    if (!nas_mobile_identity_imsi || !lai) {
+        ogs_error("!nas_mobile_identity_imsi || !lai");
         goto error;
-    if (nas_mobile_identity_imsi_len != SGSAP_IE_IMSI_LEN)
+    }
+    if (nas_mobile_identity_imsi_len != SGSAP_IE_IMSI_LEN) {
+        ogs_error("nas_mobile_identity_imsi_len != SGSAP_IE_IMSI_LEN");
         goto error;
+    }
 
     if (nas_mobile_identity_imsi->type == OGS_NAS_MOBILE_IDENTITY_IMSI) {
         ogs_nas_eps_imsi_to_bcd(nas_mobile_identity_imsi,
                 nas_mobile_identity_imsi_len, imsi_bcd);
         mme_ue = mme_ue_find_by_imsi_bcd(imsi_bcd);
-    } else
+    } else {
+        ogs_error("nas_mobile_identity_imsi->type == "
+                "OGS_NAS_MOBILE_IDENTITY_IMSI");
         goto error;
+    }
 
-    if (!mme_ue)
+    if (!mme_ue) {
+        ogs_error("!mme_ue");
         goto error;
+    }
 
     ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
     if (lai) {
@@ -138,8 +149,10 @@ void sgsap_handle_location_update_reject(mme_vlr_t *vlr, ogs_pkbuf_t *pkbuf)
     ogs_pkbuf_pull(pkbuf, 1);
 
     root = ogs_tlv_parse_block(pkbuf->len, pkbuf->data, OGS_TLV_MODE_T1_L1);
-    if (!root)
+    if (!root) {
+        ogs_error("!root");
         goto error;
+    }
 
     iter = root;
     while (iter) {
@@ -163,17 +176,24 @@ void sgsap_handle_location_update_reject(mme_vlr_t *vlr, ogs_pkbuf_t *pkbuf)
 
     ogs_tlv_free_all(root);
 
-    if (!nas_mobile_identity_imsi || !emm_cause)
+    if (!nas_mobile_identity_imsi || !emm_cause) {
+        ogs_error("!nas_mobile_identity_imsi || !emm_cause");
         goto error;
-    if (nas_mobile_identity_imsi_len != SGSAP_IE_IMSI_LEN)
+    }
+    if (nas_mobile_identity_imsi_len != SGSAP_IE_IMSI_LEN) {
+        ogs_error("nas_mobile_identity_imsi_len != SGSAP_IE_IMSI_LEN");
         goto error;
+    }
 
     if (nas_mobile_identity_imsi->type == OGS_NAS_MOBILE_IDENTITY_IMSI) {
         ogs_nas_eps_imsi_to_bcd(nas_mobile_identity_imsi,
                 nas_mobile_identity_imsi_len, imsi_bcd);
         mme_ue = mme_ue_find_by_imsi_bcd(imsi_bcd);
-    } else
+    } else {
+        ogs_error("nas_mobile_identity_imsi->type == "
+                    "OGS_NAS_MOBILE_IDENTITY_IMSI");
         goto error;
+    }
 
     ogs_expect_or_return(mme_ue);
 
diff --git a/tests/common/sgsap-build.c b/tests/common/sgsap-build.c
index 410d443ed..afbb5d814 100644
--- a/tests/common/sgsap-build.c
+++ b/tests/common/sgsap-build.c
@@ -25,7 +25,7 @@ ogs_pkbuf_t *test_sgsap_location_update_accept(int i)
 {
     ogs_pkbuf_t *pkbuf = NULL;
     const char *payload[TEST_SGSAP_MAX_MESSAGE] = {
-        "0a01089910073746 000006040509f107 09260e05f49ee88e 64",
+        "0a01089999073746 000006040509f107 09260e05f49ee88e 64",
         "0a01087942120000 000030040527f412 c9580e05f437ab9c c5",
         "",
 
@@ -49,7 +49,7 @@ ogs_pkbuf_t *test_sgsap_location_update_reject(int i)
 {
     ogs_pkbuf_t *pkbuf = NULL;
     const char *payload[TEST_SGSAP_MAX_MESSAGE] = {
-        "0b01089910073746 0000060f01030405 09f1070926",
+        "0b01089999073746 0000060f01030405 09f1070926",
         "",
         "",
 
@@ -73,7 +73,7 @@ ogs_pkbuf_t *test_sgsap_imsi_detach_ack(int i)
 {
     ogs_pkbuf_t *pkbuf = NULL;
     const char *payload[TEST_SGSAP_MAX_MESSAGE] = {
-        "1401089910073746 000006",
+        "1401089999073746 000006",
         "",
         "",
 
@@ -97,15 +97,15 @@ ogs_pkbuf_t *test_sgsap_paging_request(int i)
 {
     ogs_pkbuf_t *pkbuf = NULL;
     const char *payload[TEST_SGSAP_MAX_MESSAGE] = {
-        "0101089910073746 000006021003766c 72076578616d706c 65036e6574200101"
+        "0101089999073746 000006021003766c 72076578616d706c 65036e6574200101"
         "040509f1070926",
-        "0101089910073746 000005021003766c 72076578616d706c 65036e6574200101"
+        "0101089999073746 000005021003766c 72076578616d706c 65036e6574200101"
         "040509f1070926",  /* Paging-Reject */
-        "0101089910073746 000006021003766c 72076578616d706c 65036e6574200102"
+        "0101089999073746 000006021003766c 72076578616d706c 65036e6574200102"
         "040509f1070926",  /* Paging-Request with SMS */
 
         /* Paging-Request for crash-test */
-        "0101089910073746 000006021003766c 72076578616d706c 65036e6574200101"
+        "0101089999073746 000006021003766c 72076578616d706c 65036e6574200101"
         "040527f412c958",
         "",
         "",
@@ -157,7 +157,7 @@ ogs_pkbuf_t *test_sgsap_release_request(int i)
 {
     ogs_pkbuf_t *pkbuf = NULL;
     const char *payload[TEST_SGSAP_MAX_MESSAGE] = {
-        "1b01089910073746 000006",
+        "1b01089999073746 000006",
         "",
         "",
 
@@ -181,7 +181,7 @@ ogs_pkbuf_t *test_sgsap_downlink_unitdata(int i)
 {
     ogs_pkbuf_t *pkbuf = NULL;
     const char *payload[TEST_SGSAP_MAX_MESSAGE] = {
-        "0701089910073746 0000061626090123 0100079144775810 0650001700048032"
+        "0701089999073746 0000061626090123 0100079144775810 0650001700048032"
         "2400009160404044 150009c8329bfd06 4d9b53",
 
     };
diff --git a/tests/unit/crash-test.c b/tests/unit/crash-test.c
index d35dc0cec..c31664b6a 100644
--- a/tests/unit/crash-test.c
+++ b/tests/unit/crash-test.c
@@ -519,7 +519,7 @@ static ogs_pkbuf_t *test_build_uplink_nas_transport(
 
     EUTRAN_CGI = &ie->value.choice.EUTRAN_CGI;
 
-    ogs_plmn_id_build(&plmn_id, 901, 70, 2);
+    ogs_plmn_id_build(&plmn_id, 999, 70, 2);
 
     ogs_s1ap_buffer_to_OCTET_STRING(
             &plmn_id, OGS_PLMN_ID_LEN, &EUTRAN_CGI->pLMNidentity);
diff --git a/tests/volte/diameter-rx-path.c b/tests/volte/diameter-rx-path.c
index fbdb77744..a64ee6e31 100644
--- a/tests/volte/diameter-rx-path.c
+++ b/tests/volte/diameter-rx-path.c
@@ -1269,7 +1269,7 @@ void test_rx_send_aar_ctrl(uint8_t **rx_sid, test_sess_t *sess, int id_type)
     ogs_assert(sess->ue_ip.ipv4);
     ipstr = ogs_ipv4_to_string(sess->ue_ip.addr);
     ogs_assert(ipstr);
-    sip_uri = ogs_msprintf("sip:%s@ims.mnc0970.mcc901.3gppnetwork.org", ipstr);
+    sip_uri = ogs_msprintf("sip:%s@ims.mnc0970.mcc999.3gppnetwork.org", ipstr);
     ogs_assert(sip_uri);
 
     rv = ogs_ipsubnet(&ipsub, ipstr, NULL);