diff --git a/models/tapi/src/main/yang/tapi-odu@2017-05-31.yang b/models/tapi/src/main/yang/tapi-odu@2017-05-31.yang
index 2d5496b..00a5bc9 100644
--- a/models/tapi/src/main/yang/tapi-odu@2017-05-31.yang
+++ b/models/tapi/src/main/yang/tapi-odu@2017-05-31.yang
@@ -75,25 +75,10 @@
                 It is present only if the CEP contains a TTP";
         }
         grouping odu-connection-end-point-spec {
-            container odu-common {
-                uses odu-common-pac;
-                description "none";
-            }
-            container odu-term-and-adapter {
-                config false;
-                uses odu-termination-and-client-adaptation-pac;
-                description "none";
-            }
-            container odu-ctp {
-                config false;
-                uses odu-ctp-pac;
-                description "none";
-            }
-            container odu-protection {
-                config false;
-                uses odu-protection-pac;
-                description "none";
-            }
+            uses tapi-odu:odu-common-pac;
+            uses tapi-odu:odu-termination-and-client-adaptation-pac;
+            uses tapi-odu:odu-ctp-pac;
+            uses tapi-odu:odu-protection-pac;
             description "none";
         }
         grouping odu-pool-pac {
@@ -114,11 +99,7 @@
             description "none";
         }
         grouping odu-node-edge-point-spec {
-            container odu-pool {
-                config false;
-                uses odu-pool-pac;
-                description "none";
-            }
+            uses tapi-odu:odu-pool-pac;
             description "none";
         }
         grouping odu-ctp-pac {
@@ -151,28 +132,11 @@
                 It is present only if the CEP contains a CTP";
         }
         grouping odu-mep-spec {
-            container odu-mep {
-                uses odu-mep-pac;
-                description "none";
-            }
-            container odu-ncm {
-                config false;
-                uses odu-ncm-pac;
-                description "none";
-            }
-            container odu-tcm {
-                config false;
-                uses odu-tcm-mep-pac;
-                description "none";
-            }
-            container odu-defect {
-                uses odu-defect-pac;
-                description "none";
-            }
-            container odu-pm {
-                uses odu-pm-pac;
-                description "none";
-            }
+            uses tapi-odu:odu-mep-pac;
+            uses tapi-odu:odu-ncm-pac;
+            uses tapi-odu:odu-tcm-mep-pac;
+            uses tapi-odu:odu-defect-pac;
+            uses tapi-odu:odu-pm-pac;
             description "none";
         }
         grouping odu-protection-pac {
@@ -231,29 +195,11 @@
             description "none";
         }
         grouping odu-mip-spec {
-            container odu-mip {
-                config false;
-                uses odu-mip-pac;
-                description "none";
-            }
-            container odu-ncm {
-                config false;
-                uses odu-ncm-pac;
-                description "none";
-            }
-            container odu-tcm {
-                config false;
-                uses odu-tcm-mip-pac;
-                description "none";
-            }
-            container odu-pm {
-                uses odu-pm-pac;
-                description "none";
-            }
-            container odu-defect {
-                uses odu-defect-pac;
-                description "none";
-            }
+            uses tapi-odu:odu-mip-pac;
+            uses tapi-odu:odu-ncm-pac;
+            uses tapi-odu:odu-tcm-mip-pac;
+            uses tapi-odu:odu-pm-pac;
+            uses tapi-odu:odu-defect-pac;
             description "none";
         }
         grouping odu-mip-pac {
@@ -403,136 +349,30 @@
     /***********************
     * package type-definitions
     **********************/ 
-        identity deg-thr-type {
-            description "none";
-        }
-        identity percentage {
-            base deg-thr-type;
-            description "Choice of % or Number of errored blocks";
-        }
-        identity number-errored-blocks {
-            base deg-thr-type;
-            description "Number of % or blocks";
-        }
-        identity tcm-status {
-            description "none";
-        }
-        identity no-source-tc {
-            base tcm-status;
-            description "TCM byte 3 (bits 6 7 8) -- 0 0 0, No source Tandem Connection";
-        }
-        identity in-use-without-iae {
-            base tcm-status;
-            description "TCM byte 3 (bits 6 7 8) -- 0 0 1,  In use without IAE (Incoming Alignment Error)";
-        }
-        identity in-use-with-iae {
-            base tcm-status;
-            description "TCM byte 3 (bits 6 7 8) -- 0 1 0, In use with IAE (Incoming Alignment Error)";
-        }
-        identity reserved-1 {
-            base tcm-status;
-            description "TCM byte 3 (bits 6 7 8) -- 0 1 1, Reserved for future international standardization";
-        }
-        identity reserved-2 {
-            base tcm-status;
-            description "TCM byte 3 (bits 6 7 8) -- 1 0 0, Reserved for future international standardization";
-        }
-        identity lck {
-            base tcm-status;
-            description "TCM byte 3 (bits 6 7 8) -- 1 0 1, Maintenance signal: ODU-LCK";
-        }
-        identity oci {
-            base tcm-status;
-            description "TCM byte 3 (bits 6 7 8) -- 1 1 0, Maintenance signal: ODU-OCI";
-        }
-        identity ais {
-            base tcm-status;
-            description "TCM byte 3 (bits 6 7 8) -- 1 1 1, Maintenance signal: ODU-AIS";
-        }
-        identity tcm-mode {
-            description "none";
-        }
-        identity operational {
-            base tcm-mode;
-            description "none";
-        }
-        identity transparent {
-            base tcm-mode;
-            description "none";
-        }
-        identity monitor {
-            base tcm-mode;
-            description "none";
-        }
-        identity tcm-monitoring {
-            description "none";
-        }
-        identity intrusive {
-            base tcm-monitoring;
-            description "none";
-        }
-        identity non-intrusive {
-            base tcm-monitoring;
-            description "none";
-        }
-        identity tcm-extension {
-            description "none";
-        }
-        identity normal {
-            base tcm-extension;
-            description "none";
-        }
-        identity pass-through {
-            base tcm-extension;
-            description "none";
-        }
-        identity erase {
-            base tcm-extension;
-            description "none";
-        }
-        identity percentage-granularity {
-            description "none";
-        }
-        identity ones {
-            base percentage-granularity;
-            description "none";
-        }
-        identity one-tenths {
-            base percentage-granularity;
-            description "value * (1/10)";
-        }
-        identity one-hundredths {
-            base percentage-granularity;
-            description "value * (1/100)";
-        }
-        identity one-thousandths {
-            base percentage-granularity;
-            description "value * (1/1000)";
-        }
         typedef odu-type {
             type enumeration {
-                enum odu-0 {
+                enum ODU0 {
                     description "none";
                 }
-                enum odu-1 {
+                enum ODU1 {
                     description "none";
                 }
-                enum odu-2 {
+                enum ODU2 {
                     description "none";
                 }
-                enum odu-2-e {
+                enum ODU2E {
                     description "none";
                 }
-                enum odu-3 {
+                enum ODU3 {
                     description "none";
                 }
-                enum odu-4 {
+                enum ODU4 {
                     description "none";
                 }
-                enum odu-flex {
+                enum ODU_FLEX {
                     description "none";
                 }
-                enum odu-cn {
+                enum ODU_CN {
                     description "none";
                 }
             }
@@ -540,22 +380,22 @@
         }
         typedef mapping-type {
             type enumeration {
-                enum amp {
+                enum AMP {
                     description "none";
                 }
-                enum bmp {
+                enum BMP {
                     description "none";
                 }
-                enum gfp-f {
+                enum GFP-F {
                     description "none";
                 }
-                enum gmp {
+                enum GMP {
                     description "none";
                 }
-                enum ttp-gfp-bmp {
+                enum TTP_GFP_BMP {
                     description "none";
                 }
-                enum null {
+                enum NULL {
                     description "none";
                 }
             }
@@ -563,16 +403,16 @@
         }
         typedef tim-det-mo {
             type enumeration {
-                enum dapi {
+                enum DAPI {
                     description "none";
                 }
-                enum sapi {
+                enum SAPI {
                     description "none";
                 }
-                enum both {
+                enum BOTH {
                     description "none";
                 }
-                enum off {
+                enum OFF {
                     description "none";
                 }
             }
@@ -580,10 +420,10 @@
         }
         typedef odu-slot-size {
             type enumeration {
-                enum 1-g-25 {
+                enum 1G25 {
                     description "none";
                 }
-                enum 2-g-5 {
+                enum 2G5 {
                     description "none";
                 }
             }
@@ -602,10 +442,10 @@
         }
         typedef odu-named-payload-type {
             type enumeration {
-                enum unknown {
+                enum UNKNOWN {
                     description "none";
                 }
-                enum uninterpretable {
+                enum UNINTERPRETABLE {
                     description "none";
                 }
             }
@@ -633,38 +473,98 @@
                 Number of Errored Blocks is captured in an integer value.";
         }
         typedef deg-thr-type {
-            type identityref {
-                base deg-thr-type;
+            type enumeration {
+                enum PERCENTAGE {
+                    description "Choice of % or Number of errored blocks";
+                }
+                enum NUMBER_ERRORED_BLOCKS {
+                    description "Number of % or blocks";
+                }
             }
             description "The value of the threshold can be provisioned in terms of number of errored blocks or in terms of percentage of errored blocks. For percentage-based specification, in order to support provision of less than 1%, the specification consists of two fields. The first field indicates the granularity of percentage. For examples, in 1%, in 0.1%, or in 0.01%, etc. The second field indicates the multiple of the granularity. For number of errored block based, the value is a positive integer.";
         }
         typedef tcm-status {
-            type identityref {
-                base tcm-status;
+            type enumeration {
+                enum NO_SOURCE_TC {
+                    description "TCM byte 3 (bits 6 7 8) -- 0 0 0, No source Tandem Connection";
+                }
+                enum IN_USE_WITHOUT_IAE {
+                    description "TCM byte 3 (bits 6 7 8) -- 0 0 1,  In use without IAE (Incoming Alignment Error)";
+                }
+                enum IN_USE_WITH_IAE {
+                    description "TCM byte 3 (bits 6 7 8) -- 0 1 0, In use with IAE (Incoming Alignment Error)";
+                }
+                enum RESERVED_1 {
+                    description "TCM byte 3 (bits 6 7 8) -- 0 1 1, Reserved for future international standardization";
+                }
+                enum RESERVED_2 {
+                    description "TCM byte 3 (bits 6 7 8) -- 1 0 0, Reserved for future international standardization";
+                }
+                enum LCK {
+                    description "TCM byte 3 (bits 6 7 8) -- 1 0 1, Maintenance signal: ODU-LCK";
+                }
+                enum OCI {
+                    description "TCM byte 3 (bits 6 7 8) -- 1 1 0, Maintenance signal: ODU-OCI";
+                }
+                enum AIS {
+                    description "TCM byte 3 (bits 6 7 8) -- 1 1 1, Maintenance signal: ODU-AIS";
+                }
             }
             description "See Table 15-5/G.709/Y.1331 ";
         }
         typedef tcm-mode {
-            type identityref {
-                base tcm-mode;
+            type enumeration {
+                enum OPERATIONAL {
+                    description "none";
+                }
+                enum TRANSPARENT {
+                    description "none";
+                }
+                enum MONITOR {
+                    description "none";
+                }
             }
             description "List of value modes for the sink side of the tandem connection monitoring function.";
         }
         typedef tcm-monitoring {
-            type identityref {
-                base tcm-monitoring;
+            type enumeration {
+                enum INTRUSIVE {
+                    description "none";
+                }
+                enum NON-INTRUSIVE {
+                    description "none";
+                }
             }
             description "Monitoring types for the tandem connection monitoring function.";
         }
         typedef tcm-extension {
-            type identityref {
-                base tcm-extension;
+            type enumeration {
+                enum NORMAL {
+                    description "none";
+                }
+                enum PASS-THROUGH {
+                    description "none";
+                }
+                enum ERASE {
+                    description "none";
+                }
             }
             description "none";
         }
         typedef percentage-granularity {
-            type identityref {
-                base percentage-granularity;
+            type enumeration {
+                enum ONES {
+                    description "none";
+                }
+                enum ONE_TENTHS {
+                    description "value * (1/10)";
+                }
+                enum ONE_HUNDREDTHS {
+                    description "value * (1/100)";
+                }
+                enum ONE_THOUSANDTHS {
+                    description "value * (1/1000)";
+                }
             }
             description "none";
         }