Adding OpenConfig YANG models.

Change-Id: I0a2fdd5826e80933cf4b9ae939ff3051acec02aa
diff --git a/models/openconfig/src/main/yang/types/openconfig-inet-types.yang b/models/openconfig/src/main/yang/types/openconfig-inet-types.yang
new file mode 100644
index 0000000..498a6e4
--- /dev/null
+++ b/models/openconfig/src/main/yang/types/openconfig-inet-types.yang
@@ -0,0 +1,316 @@
+module openconfig-inet-types {
+
+  yang-version "1";
+  namespace "http://openconfig.net/yang/types/inet";
+  prefix "oc-inet";
+
+  import openconfig-extensions { prefix "oc-ext"; }
+
+  organization
+    "OpenConfig working group";
+
+  contact
+    "OpenConfig working group
+    www.openconfig.net";
+
+  description
+    "This module contains a set of Internet address related
+    types for use in OpenConfig modules.
+
+    Portions of this code were derived from IETF RFC 6021.
+    Please reproduce this note if possible.
+
+    IETF code is subject to the following copyright and license:
+    Copyright (c) IETF Trust and the persons identified as authors of
+    the code.
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, is permitted pursuant to, and subject to the license
+    terms contained in, the Simplified BSD License set forth in
+    Section 4.c of the IETF Trust's Legal Provisions Relating
+    to IETF Documents (http://trustee.ietf.org/license-info).";
+
+  oc-ext:openconfig-version "0.3.0";
+
+  revision 2017-07-06 {
+    description
+      "Add domain-name and host typedefs";
+    reference "0.3.0";
+  }
+
+  revision 2017-04-03 {
+    description
+      "Add ip-version typedef.";
+    reference "0.2.0";
+  }
+
+  revision 2017-04-03 {
+    description
+      "Update copyright notice.";
+    reference "0.1.1";
+  }
+
+  revision 2017-01-26 {
+    description
+      "Initial module for inet types";
+    reference "0.1.0";
+  }
+
+  // IPv4 and IPv6 types.
+
+  typedef ipv4-address {
+    type string {
+      pattern '^(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|'        +
+              '25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4]'  +
+              '[0-9]|25[0-5])$';
+    }
+    description
+      "An IPv4 address in dotted quad notation using the default
+      zone.";
+  }
+
+  typedef ipv4-address-zoned {
+    type string {
+      pattern '^(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|'        +
+              '25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4]'  +
+              '[0-9]|25[0-5])(%[a-zA-Z0-9_]+)$';
+    }
+    description
+      "An IPv4 address in dotted quad notation.  This type allows
+      specification of a zone index to disambiguate identical
+      address values.  For link-local addresses, the index is
+      typically the interface index or interface name.";
+  }
+
+  typedef ipv6-address {
+    type string {
+        pattern
+          // Must support compression through different lengths
+          // therefore this regexp is complex.
+          '^(([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}|'         +
+          '([0-9a-fA-F]{1,4}:){1,7}:|'                        +
+          '([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|'        +
+          '([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|' +
+          '([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|' +
+          '([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|' +
+          '([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|' +
+          '[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|'      +
+          ':((:[0-9a-fA-F]{1,4}){1,7}|:)'                     +
+          ')$';
+    }
+    description
+      "An IPv6 address represented as either a full address; shortened
+      or mixed-shortened formats, using the default zone.";
+  }
+
+  typedef ipv6-address-zoned {
+    type string {
+        pattern
+          // Must support compression through different lengths
+          // therefore this regexp is complex.
+          '^(([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}|'         +
+          '([0-9a-fA-F]{1,4}:){1,7}:|'                        +
+          '([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|'        +
+          '([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|' +
+          '([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|' +
+          '([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|' +
+          '([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|' +
+          '[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|'      +
+          ':((:[0-9a-fA-F]{1,4}){1,7}|:)'                     +
+          ')(%[a-zA-Z0-9_]+)$';
+    }
+    description
+      "An IPv6 address represented as either a full address; shortened
+      or mixed-shortened formats.  This type allows specification of
+      a zone index to disambiguate identical address values.  For
+      link-local addresses, the index is typically the interface
+      index or interface name.";
+  }
+
+  typedef ipv4-prefix {
+    type string {
+      pattern '^(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|'       +
+              '25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4]' +
+              '[0-9]|25[0-5])/(([0-9])|([1-2][0-9])|(3[0-2]))$';
+    }
+    description
+      "An IPv4 prefix represented in dotted quad notation followed by
+      a slash and a CIDR mask (0 <= mask <= 32).";
+  }
+
+  typedef ipv6-prefix {
+    type string {
+        pattern
+          '^(([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}|'         +
+          '([0-9a-fA-F]{1,4}:){1,7}:|'                        +
+          '([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}'         +
+          '([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|' +
+          '([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|' +
+          '([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|' +
+          '([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|' +
+          '[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|'      +
+          ':((:[0-9a-fA-F]{1,4}){1,7}|:)'                     +
+          ')/(12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9])$';
+    }
+    description
+      "An IPv6 prefix represented in full, shortened, or mixed
+      shortened format followed by a slash and CIDR mask
+      (0 <= mask <= 128).";
+  }
+
+  typedef ip-address {
+    type union {
+      type ipv4-address;
+      type ipv6-address;
+    }
+    description
+      "An IPv4 or IPv6 address with no prefix specified.";
+  }
+
+  typedef ip-prefix {
+    type union {
+      type ipv4-prefix;
+      type ipv6-prefix;
+    }
+    description
+      "An IPv4 or IPv6 prefix.";
+  }
+
+  typedef ip-version {
+    type enumeration {
+      enum UNKNOWN {
+        value 0;
+        description
+         "An unknown or unspecified version of the Internet
+          protocol.";
+      }
+      enum IPV4 {
+        value 4;
+        description
+         "The IPv4 protocol as defined in RFC 791.";
+      }
+      enum IPV6 {
+        value 6;
+        description
+         "The IPv6 protocol as defined in RFC 2460.";
+      }
+    }
+    description
+     "This value represents the version of the IP protocol.
+      Note that integer representation of the enumerated values
+      are not specified, and are not required to follow the
+      InetVersion textual convention in SMIv2.";
+    reference
+     "RFC  791: Internet Protocol
+      RFC 2460: Internet Protocol, Version 6 (IPv6) Specification
+      RFC 4001: Textual Conventions for Internet Network Addresses";
+  }
+
+  typedef domain-name {
+    type string {
+      length "1..253";
+      pattern
+        '((([a-zA-Z0-9_]([a-zA-Z0-9\-_]){0,61})?[a-zA-Z0-9]\.)*' +
+        '([a-zA-Z0-9_]([a-zA-Z0-9\-_]){0,61})?[a-zA-Z0-9]\.?)'   +
+        '|\.';
+    }
+    description
+      "The domain-name type represents a DNS domain name. 
+      Fully quallified left to the models which utilize this type.
+
+      Internet domain names are only loosely specified.  Section
+      3.5 of RFC 1034 recommends a syntax (modified in Section
+      2.1 of RFC 1123).  The pattern above is intended to allow
+      for current practice in domain name use, and some possible
+      future expansion.  It is designed to hold various types of
+      domain names, including names used for A or AAAA records
+      (host names) and other records, such as SRV records.  Note
+      that Internet host names have a stricter syntax (described
+      in RFC 952) than the DNS recommendations in RFCs 1034 and
+      1123, and that systems that want to store host names in
+      schema nodes using the domain-name type are recommended to
+      adhere to this stricter standard to ensure interoperability.
+
+      The encoding of DNS names in the DNS protocol is limited
+      to 255 characters.  Since the encoding consists of labels
+      prefixed by a length bytes and there is a trailing NULL
+      byte, only 253 characters can appear in the textual dotted
+      notation.
+
+      Domain-name values use the US-ASCII encoding.  Their canonical
+      format uses lowercase US-ASCII characters.  Internationalized
+      domain names MUST be encoded in punycode as described in RFC
+      3492";
+  }
+
+  typedef host {
+    type union {
+      type ip-address;
+      type domain-name;
+    }
+    description
+      "The host type represents either an unzoned IP address or a DNS
+      domain name.";
+  }
+
+  typedef as-number {
+    type uint32;
+    description
+      "A numeric identifier for an autonomous system (AS). An AS is a
+      single domain, under common administrative control, which forms
+      a unit of routing policy. Autonomous systems can be assigned a
+      2-byte identifier, or a 4-byte identifier which may have public
+      or private scope. Private ASNs are assigned from dedicated
+      ranges. Public ASNs are assigned from ranges allocated by IANA
+      to the regional internet registries (RIRs).";
+    reference
+      "RFC 1930 Guidelines for creation, selection, and registration
+                of an Autonomous System (AS)
+       RFC 4271 A Border Gateway Protocol 4 (BGP-4)";
+  }
+
+  typedef dscp {
+    type uint8 {
+      range "0..63";
+    }
+    description
+      "A differentiated services code point (DSCP) marking within the
+      IP header.";
+    reference
+      "RFC 2474 Definition of the Differentiated Services Field
+                 (DS Field) in the IPv4 and IPv6 Headers";
+  }
+
+  typedef ipv6-flow-label {
+    type uint32 {
+      range "0..1048575";
+    }
+    description
+      "The IPv6 flow-label is a 20-bit value within the IPv6 header
+      which is optionally used by the source of the IPv6 packet to
+      label sets of packets for which special handling may be
+      required.";
+    reference
+      "RFC 2460 Internet Protocol, Version 6 (IPv6) Specification";
+  }
+
+  typedef port-number {
+    type uint16;
+    description
+      "A 16-bit port number used by a transport protocol such as TCP
+      or UDP.";
+    reference
+      "RFC 768 User Datagram Protocol
+       RFC 793 Transmission Control Protocol";
+  }
+
+  typedef uri {
+    type string;
+    description
+      "An ASCII-encoded Uniform Resource Identifier (URI) as defined
+      in RFC 3986.";
+    reference
+      "RFC 3986 Uniform Resource Identifier (URI): Generic Syntax";
+  }
+}
diff --git a/models/openconfig/src/main/yang/types/openconfig-types.yang b/models/openconfig/src/main/yang/types/openconfig-types.yang
new file mode 100644
index 0000000..fa76f80
--- /dev/null
+++ b/models/openconfig/src/main/yang/types/openconfig-types.yang
@@ -0,0 +1,332 @@
+module openconfig-types {
+  yang-version "1";
+
+  namespace "http://openconfig.net/yang/openconfig-types";
+
+  prefix "oc-types";
+
+  // import statements
+  import openconfig-extensions { prefix oc-ext; }
+
+  // meta
+  organization
+    "OpenConfig working group";
+
+  contact
+    "OpenConfig working group
+    netopenconfig@googlegroups.com";
+
+  description
+    "This module contains a set of general type definitions that
+    are used across OpenConfig models. It can be imported by modules
+    that make use of these types.";
+
+  oc-ext:openconfig-version "0.3.3";
+
+  revision "2017-08-16" {
+    description
+      "Apply fix for ieetfloat32 length parameter";
+    reference "0.3.3";
+  }
+
+  revision "2017-01-13" {
+    description
+      "Add ADDRESS_FAMILY identity";
+    reference "0.3.2";
+  }
+
+  revision "2016-11-14" {
+    description
+      "Correct length of ieeefloat32";
+    reference "0.3.1";
+  }
+
+  revision "2016-11-11" {
+    description
+      "Additional types - ieeefloat32 and routing-password";
+    reference "0.3.0";
+  }
+
+  revision "2016-05-31" {
+    description
+      "OpenConfig public release";
+    reference "0.2.0";
+  }
+
+  typedef percentage {
+    type uint8 {
+      range "0..100";
+    }
+    description
+      "Integer indicating a percentage value";
+  }
+
+  typedef std-regexp {
+    type string;
+    description
+      "This type definition is a placeholder for a standard
+      definition of a regular expression that can be utilised in
+      OpenConfig models. Further discussion is required to
+      consider the type of regular expressions that are to be
+      supported. An initial proposal is POSIX compatible.";
+  }
+
+  typedef timeticks64 {
+    type uint64;
+    description
+     "This type is based on the timeticks type defined in
+     RFC 6991, but with 64-bit width.  It represents the time,
+     modulo 2^64, in hundredths of a second between two epochs.";
+    reference
+      "RFC 6991 - Common YANG Data Types";
+  }
+
+  typedef ieeefloat32 {
+    type binary {
+      length "4";
+    }
+    description
+      "An IEEE 32-bit floating point number. The format of this number
+      is of the form:
+        1-bit  sign
+        8-bit  exponent
+        23-bit fraction
+      The floating point value is calculated using:
+        (-1)**S * 2**(Exponent-127) * (1+Fraction)";
+  }
+
+  typedef routing-password {
+    type string;
+    description
+      "This type is indicative of a password that is used within
+      a routing protocol which can be returned in plain text to the
+      NMS by the local system. Such passwords are typically stored
+      as encrypted strings. Since the encryption used is generally
+      well known, it is possible to extract the original value from
+      the string - and hence this format is not considered secure.
+      Leaves specified with this type should not be modified by
+      the system, and should be returned to the end-user in plain
+      text. This type exists to differentiate passwords, which
+      may be sensitive, from other string leaves. It could, for
+      example, be used by the NMS to censor this data when
+      viewed by particular users.";
+  }
+
+  grouping avg-min-max-stats-precision1 {
+    description
+      "Common nodes for recording average, minimum, and
+      maximum values for a statistic.  These values all have
+      fraction-digits set to 1.";
+
+    leaf avg {
+      type decimal64 {
+        fraction-digits 1;
+      }
+      description
+        "The arithmetic mean value of the statistic over the
+        sampling period.";
+    }
+
+    leaf min {
+      type decimal64 {
+        fraction-digits 1;
+      }
+      description
+        "The minimum value of the statistic over the sampling
+        period";
+    }
+
+    leaf max {
+      type decimal64 {
+        fraction-digits 1;
+      }
+      description
+        "The maximum value of the statitic over the sampling
+        period";
+    }
+  }
+
+  grouping avg-min-max-instant-stats-precision1 {
+    description
+      "Common grouping for recording an instantaneous statistic value
+      in addition to avg-min-max stats";
+
+    leaf instant {
+      type decimal64 {
+        fraction-digits 1;
+      }
+      description
+        "The instantaneous value of the statistic.";
+    }
+
+    uses avg-min-max-stats-precision1;
+  }
+
+  grouping avg-min-max-instant-stats-precision2-dB {
+    description
+      "Common grouping for recording dB values with 2 decimal
+      precision. Values include the instantaneous, average,
+      minimum, and maximum statistics";
+
+    leaf instant {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units dB;
+      description
+        "The instantaneous value of the statistic.";
+    }
+
+    leaf avg {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units dB;
+      description
+        "The arithmetic mean value of the statistic over the
+        sampling period.";
+    }
+
+    leaf min {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units dB;
+      description
+        "The minimum value of the statistic over the sampling
+        period";
+    }
+
+    leaf max {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units dB;
+      description
+        "The maximum value of the statistic over the sampling
+        period";
+    }
+  }
+
+  grouping avg-min-max-instant-stats-precision2-dBm {
+    description
+      "Common grouping for recording dBm values with 2 decimal
+      precision. Values include the instantaneous, average,
+      minimum, and maximum statistics";
+
+    leaf instant {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units dBm;
+      description
+        "The instantaneous value of the statistic.";
+    }
+
+    leaf avg {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units dBm;
+      description
+        "The arithmetic mean value of the statistic over the
+        sampling period.";
+    }
+
+    leaf min {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units dBm;
+      description
+        "The minimum value of the statistic over the sampling
+        period";
+    }
+
+    leaf max {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units dBm;
+      description
+        "The maximum value of the statistic over the sampling
+        period";
+    }
+  }
+
+  grouping avg-min-max-instant-stats-precision2-mA {
+    description
+      "Common grouping for recording mA values with 2 decimal
+      precision. Values include the instantaneous, average,
+      minimum, and maximum statistics";
+
+    leaf instant {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units mA;
+      description
+        "The instantaneous value of the statistic.";
+    }
+
+    leaf avg {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units mA;
+      description
+        "The arithmetic mean value of the statistic over the
+        sampling period.";
+    }
+
+    leaf min {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units mA;
+      description
+        "The minimum value of the statistic over the sampling
+        period";
+    }
+
+    leaf max {
+      type decimal64 {
+        fraction-digits 2;
+      }
+      units mA;
+      description
+        "The maximum value of the statistic over the sampling
+        period";
+    }
+  }
+
+  identity ADDRESS_FAMILY {
+    description
+      "A base identity for all address families";
+  }
+
+  identity IPV4 {
+    base ADDRESS_FAMILY;
+    description
+      "The IPv4 address family";
+  }
+
+  identity IPV6 {
+    base ADDRESS_FAMILY;
+    description
+      "The IPv6 address family";
+  }
+
+  identity MPLS {
+    base ADDRESS_FAMILY;
+    description
+      "The MPLS address family";
+  }
+
+  identity L2_ETHERNET {
+    base ADDRESS_FAMILY;
+    description
+      "The 802.3 Ethernet address family";
+  }
+
+}
diff --git a/models/openconfig/src/main/yang/types/openconfig-yang-types.yang b/models/openconfig/src/main/yang/types/openconfig-yang-types.yang
new file mode 100644
index 0000000..749fac4
--- /dev/null
+++ b/models/openconfig/src/main/yang/types/openconfig-yang-types.yang
@@ -0,0 +1,156 @@
+module openconfig-yang-types {
+
+  yang-version "1";
+  namespace "http://openconfig.net/yang/types/yang";
+  prefix "oc-yang";
+
+  import openconfig-extensions { prefix "oc-ext"; }
+
+  organization
+    "OpenConfig working group";
+
+  contact
+    "OpenConfig working group
+    www.openconfig.net";
+
+  description
+    "This module contains a set of extension types to the
+    YANG builtin types that are used across multiple
+    OpenConfig models.
+
+    Portions of this code were derived from IETF RFC 6021.
+    Please reproduce this note if possible.
+
+    IETF code is subject to the following copyright and license:
+    Copyright (c) IETF Trust and the persons identified as authors of
+    the code.
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, is permitted pursuant to, and subject to the license
+    terms contained in, the Simplified BSD License set forth in
+    Section 4.c of the IETF Trust's Legal Provisions Relating
+    to IETF Documents (http://trustee.ietf.org/license-info).";
+
+  oc-ext:openconfig-version "0.1.2";
+
+  revision 2017-07-30 {
+    description
+      "Fixed unprintable character";
+    reference "0.1.2";
+  }
+
+  revision 2017-04-03 {
+    description
+      "Update copyright notice.";
+    reference "0.1.1";
+  }
+
+  revision 2017-01-26 {
+    description
+      "Initial module for inet types";
+    reference "0.1.0";
+  }
+
+  typedef dotted-quad {
+    type string {
+      pattern '^(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|'       +
+              '25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4]' +
+              '[0-9]|25[0-5])$';
+    }
+    description
+      "An unsigned 32-bit integer expressed as a dotted quad. The
+      format is four octets written as decimal numbers separated
+      with a period character.";
+  }
+
+  typedef hex-string {
+    type string {
+      pattern '^[0-9a-fA-F]*$';
+    }
+    description
+      "A string consisting of a hexadecimal characters.";
+  }
+
+  typedef counter32 {
+    type uint32;
+    description
+
+      "A 32-bit counter. A counter value is a monotonically increasing
+      value which is used to express a count of a number of
+      occurrences of a particular event or entity. When the counter
+      reaches its maximum value, in this case 2^32-1, it wraps to 0.
+
+      Discontinuities in the counter are generally triggered only when
+      the counter is reset to zero.";
+  }
+
+  typedef counter64 {
+    type uint64;
+    description
+
+      "A 64-bit counter. A counter value is a monotonically increasing
+      value which is used to express a count of a number of
+      occurrences of a particular event or entity. When a counter64
+      reaches its maximum value, 2^64-1, it loops to zero.
+      Discontinuities in a counter are generally triggered only when
+      the counter is reset to zero, through operator or system
+      intervention.";
+  }
+
+  typedef date-and-time {
+    type string {
+      pattern
+        '^[0-9]{4}\-[0-9]{2}\-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}' +
+        '(\.[0-9]+)?Z[+-][0-9]{2}:[0-9]{2}$';
+    }
+    description
+      "A date and time, expressed in the format described in RFC3339.
+      That is to say:
+
+      YYYY-MM-DDTHH:MM:SSZ+-hh:mm
+
+      where YYYY is the year, MM is the month expressed as a two-digit
+      month (zero padding if required), DD is the day of the month,
+      expressed as a two digit value. T is the literal character 'T',
+      HH is the hour of the day expressed as a two digit number, using
+      the 24-hour clock, MM is the minute of the hour expressed as a
+      two digit number. Z is the literal character 'Z', followed by a
+      timezone offset expressed in hours (hh) and minutes (mm), both
+      expressed as two digit numbers. The time offset is specified as
+      a positive or negative offset to UTC using the '+' or '-'
+      character preceding the offset.
+
+      Optionally, fractional seconds can be expressed after the minute
+      of the hour as a decimal number of unspecified precision
+      reflecting fractions of a second.";
+    reference
+      "RFC3339 - Date and Time on the Internet: Timestamps";
+  }
+
+  typedef gauge64 {
+    type uint64;
+    description
+      "A gauge value may increase or decrease - and reflects a value
+      at a particular point in time. If the value of the variable
+      being modeled using the gauge exceeds its maximum - 2^64-1 in
+      this case - the gauge is set to its maximum value.";
+  }
+
+  typedef phys-address {
+    type string {
+      pattern '^([0-9a-fA-F]{2}(:[0-9a-fA-F]{2})*)?$';
+    }
+    description
+      "A physical layer address, expressed as a series of pairs of
+      hexadecimal digits.";
+  }
+
+  typedef mac-address {
+    type string {
+      pattern '^[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}$';
+    }
+    description
+      "An IEEE 802 MAC address";
+  }
+}