Internet Engineering Task Force A. Somaraju, Ed. Internet-Draft Tridonic GmbH & Co KG Intended status: Standards Track M. Veillette, Ed. Expires: January 9, 2017 Trilliant Networks Inc. A. Pelov Acklio R. Turner Landis+Gyr A. Minaburo Acklio July 08, 2016 Structure Identifier (SID) draft-somaraju-core-sid-01 Abstract Structured IDentifiers (SID) are used to identify different YANG items when encoded in CBOR. This document defines the registration and assignment processes of SIDs. To enable the implementation of these processes, this document also defines a file format used to persist and publish assigned SIDs. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on January 9, 2017. Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents Somaraju, et al. Expires January 9, 2017 [Page 1] Internet-Draft Structure Identifier (SID) July 2016 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology and Notation . . . . . . . . . . . . . . . . . . 2 3. Structured IDentifiers (SID) . . . . . . . . . . . . . . . . 3 4. ".sid" file lifecycle . . . . . . . . . . . . . . . . . . . . 4 5. ".sid" file format . . . . . . . . . . . . . . . . . . . . . 6 6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 7.1. "SID" range registry . . . . . . . . . . . . . . . . . . 9 7.2. YANG module registry . . . . . . . . . . . . . . . . . . 11 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 9.1. Normative References . . . . . . . . . . . . . . . . . . 12 9.2. Informative References . . . . . . . . . . . . . . . . . 12 Appendix A. ".sid" file example . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 1. Introduction This document describes the registries required to manage SIDs and a file format used to persist and publish the assigned SIDs. 2. Terminology and Notation The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. The following terms are defined in [I-D.ietf-netmod-rfc6020bis]: o action o feature o module o notification o RPC Somaraju, et al. Expires January 9, 2017 [Page 2] Internet-Draft Structure Identifier (SID) July 2016 o schema node o schema tree o submodule This specification also makes use of the following terminology: o identifier: An identifier embodies the information required to distinguish what is being identified from all other things within its scope of identification. o delta : Difference between the current SID and a reference SID. A reference SID is defined for each context for which deltas are used. o item: A schema node, an identity, a module, a submodule or a feature defined using the YANG modeling language. o path: A path is a string that identifies a schema node within the schema tree. A path consists of the list of schema node identifier(s) separated by slashes ("/"). Schema node identifier(s) are always listed from the top-level schema node up to the targeted schema node. (e.g. "/system-state/clock/current- datetime") 3. Structured IDentifiers (SID) Some of the items defined in YANG [I-D.ietf-netmod-rfc6020bis] require the use of a unique identifier. In both NETCONF and RESTCONF, these identifiers are implemented using names. To allow the implementation of data models defined in YANG in constrained devices and constrained networks, a more compact method to identify YANG items is required. This compact identifier, called SID, is encoded using an unsigned integer. To minimize its size, SIDs are often implemented using a delta from a reference SID and the current SID. To guaranty the uniqueness of each assigned SID, SID ranges MUST be registered. Section 7.1 provide more details about the registration process of SID range(s). To avoid duplicate assignment of SIDs, the registration of the SIDs assigned to YANG module(s) is recommended. Section 7.2 provide more details about the registration process of YANG modules. The following items are identified using SIDs: Somaraju, et al. Expires January 9, 2017 [Page 3] Internet-Draft Structure Identifier (SID) July 2016 o identities o data nodes o RPCs and associated input(s) and output(s) o actions and associated input(s) and output(s) o notifications and associated information o YANG modules, submodules and features Assignment of SIDs can be automated, the recommended process to assign SIDs is as follows: o A tool extracts the different items defined for a specific YANG module. o The list of items is ordered by type and label. o SIDs are assigned sequentially for the entry point up to the size of the registered SID range. It is important to note that sequentially assigning SIDs optimizes the CBOR serialization due to the use of delta encoding. o If the number of items exceeds the SID range(s) allocated to a YANG module, an extra range is added for subsequent assignments. SIDs are assigned permanently, items introduced by a new revision of a YANG module are added to the list of SIDs already assigned. This process can also be automated using the same method described above except that the assignment need to be restarted from the highest SID already assigned. Section 5 defines a standard file format used to store and publish SIDs. 4. ".sid" file lifecycle The following activity diagram summarize the life cycle of ".sid" files. Somaraju, et al. Expires January 9, 2017 [Page 4] Internet-Draft Structure Identifier (SID) July 2016 +---------------+ O | Creation of a | -|- ->| YANG module | / \ +---------------+ | V /-------------\ / Standardized \ yes \ YANG module ? /-------------+ \-------------/ | | no | V V /-------------\ +---------------+ / Constrained \ yes | SID range | +-->\ application ? /---->| registration | | \-------------/ +---------------+ | | no | | V V | +---------------+ +---------------+ +---| YANG module | | .sid file | | update | | generation | +---------------+ +---------------+ | V /-------------\ +---------------+ / Publicly \ yes | YANG module | +------------>\ available ? /---->| registration | | \-------------/ +---------------+ | | no | | +---------------------+ | V +---------------+ +---------------+ | .sid file | | Update of the | | update based | | YANG module | | on previous | | or include(s) | | .sid file | | or import(s) | +---------------+ +---------------+ ^ | | V | /-------------\ +---------------+ | / More SIDs \ yes | Extra range | | \ required ? /---->| assignment | | \-------------/ +---------------+ | | no | +---------------------+---------------------+ Somaraju, et al. Expires January 9, 2017 [Page 5] Internet-Draft Structure Identifier (SID) July 2016 YANG modules are not necessary created in the context of constrained applications. YANG modules can be implemented using NETCONF or RESTCONF without the need to assign SIDs. As needed, authors of YANG modules can assign SIDs to their modules. This process starts by the registration of a SID range. Once a SID range is registered, the owner of this range assigns sub-ranges to each YANG module in order to generate the associated ".sid" files. Generation of ".sid" files SHOULD be performed using an automated tool. Registration of the .sid file associated to a YANG module is optional but recommended to promote interoperability between devices and to avoid duplicate allocation of SIDs to a single YANG module. Each time a YANG module or one of its imported module(s) or included sub-module(s) is updated, the ".sid" file MAY need to be updated. This update SHOULD also be performed using an automated tool. If a new revision requires more SIDs than initially allocated, a new SID range MUST be added to the assignment ranges as defined in the ".sid" file header. These extra SIDs are used for subsequent assignments. 5. ".sid" file format ".sid" files are used to persist and publish SIDs assigned to the different YANG items of a specific YANG module. The following YANG module defined the structure of this file, encoding is performed using the rules defined in [I-D.ietf-netmod-yang-json]. file "ietf-sid-file@2015-12-16.yang" module ietf-sid-file { namespace "urn:ietf:params:xml:ns:yang:ietf-sid-file"; prefix sid; organization "IETF Core Working Group"; contact "Ana Minaburo Alexander Pelov Abhinav Somaraju Somaraju, et al. Expires January 9, 2017 [Page 6] Internet-Draft Structure Identifier (SID) July 2016 Laurent Toutain Randy Turner Michel Veillette "; description "This module define the structure of the .sid files. .sid files contains the identifiers (SIDs) assigned to the different items defined in a YANG module. SIDs are used to encode a data model defined in YANG using CBOR."; revision 2015-12-16 { description "Initial revision."; reference "RFC XXXX"; // RFC Ed.: replace XXXX with RFC number assigned to draft-ietf-core-yang-cbor and remove this note } typedef yang-identifier { type string { length "1..max"; pattern '[a-zA-Z_][a-zA-Z0-9\-_.]*'; pattern '.|..|[^xX].*|.[^mM].*|..[^lL].*'; } description "A YANG identifier string as defined by the 'identifier' rule in Section 12 of RFC 6020."; } typedef revision-identifier { type string { pattern '\d{4}-\d{2}-\d{2}'; } description "Represents a date in YYYY-MM-DD format."; } leaf module-name { type yang-identifier; description "Name of the module associated with this .sid file."; } Somaraju, et al. Expires January 9, 2017 [Page 7] Internet-Draft Structure Identifier (SID) July 2016 leaf module-revision { type revision-identifier; description "Revision of the module associated with this .sid file. This leaf is not present if no revision statement is defined in the YANG module."; } list assigment-ranges { key "entry-point"; description "Range(s) of SIDs available for assignment to the different items defined by the associated module."; leaf entry-point { type uint32; mandatory true; description "Lowest SID available for assignment."; } leaf size { type uint16; mandatory true; description "Number of SIDs available for assignment."; } } list items { key "type label"; description "List of items defined by the associated YANG module."; leaf type { type string { pattern 'Module|Submodule|feature|' + 'identity$|node$|notification$|rpc$|action$'; } mandatory true; description "Item type assigned, this field can be set to: - 'Module' - 'Submodule' - 'feature' - 'identity' - 'node' - 'notification' Somaraju, et al. Expires January 9, 2017 [Page 8] Internet-Draft Structure Identifier (SID) July 2016 - 'rpc' - 'action'"; } leaf label { type string; mandatory true; description "Label associated to this item, can be set to: - a module name - a submodule name - a feature name - a base identity encoded as '/' - an identity encoded as '//' - a schema node path"; } leaf sid { type uint32; mandatory true; description "Identifier assigned to this YANG item."; } } } 6. Security Considerations The security considerations of [RFC7049] and [I-D.ietf-netmod-rfc6020bis] apply. This document defines an new type of identifier used to encode data models defined in YANG [I-D.ietf-netmod-rfc6020bis]. As such, this identifier does not contribute to any new security issues in addition of those identified for the specific protocols or contexts for which it is used. 7. IANA Considerations 7.1. "SID" range registry IANA is requested to create a registry for Structure Identifier (SID) ranges. This registry needs to guarantee that the ranges registered do not overlap. The registry SHALL record for each entry: o The entry point (first entry) of the registered SID range. o The size of the registered SID range. Somaraju, et al. Expires January 9, 2017 [Page 9] Internet-Draft Structure Identifier (SID) July 2016 o The contact information of the owner of the range such as name, email address, and phone number. The IANA policy for this registry is split into four tiers as follows: o The range of 0 to 999 and 0x40000000 to 0xFFFFFFFFFFFFFFFF are reserved for future extensions of this protocol. Allocation within these ranges require IETF review or IESG approval. o The range of 1000 to 59999 is reserved for standardized YANG modules. Allocation within this range requires publishing of the associated ".yang" and ".sid" files. (Specification required.) o The range of 60000 to 99999 is reserved for experimental YANG modules. Use of this range MUST NOT be used in operational deployments since these SIDs are not globally unique which limit their interoperability. o The range of 100000 to 0x3FFFFFFF is available on a first come first served basis. The only information required from the registrant is a valid contact information. The recommended size of the SID ranges allocated is 1,000 for private use and 10,000 for standard development organizations (SDOs). Registrants MAY request fewer or more SIDs based on their expected, sat needs. Allocation of a significantly larger SID range MAY required IETF review or IESG approval. IANA MAY delegate this registration process to one or multiple sub-registries. The recommended size of the SID range allocation for a sub-registry is 1,000,000. +------------+-----------------+------------------------------------+ | Entry | Size | Registration Procedures | | Point | | | +------------+-----------------+------------------------------------+ | 0 | 1,000 | IETF review or IESG approval | | 1,000 | 59,000 | Specification and associated | | | | ".yang" and ".sid" files required | | 60,000 | 40,000 | Experimental use | | 100,000 | 0x3ffe7960 | Contact information is required. | | | | Registration of the module name(s) | | | | and associated ".yang" and ".sid" | | | | files are optional. | | 0x40000000 | 2^64-0x40000000 | Specification required, expert | | | | review | +------------+-----------------+------------------------------------+ Somaraju, et al. Expires January 9, 2017 [Page 10] Internet-Draft Structure Identifier (SID) July 2016 7.2. YANG module registry Each registered SID range can be used to assign SIDs to one or more YANG modules. To track which YANG modules have been assigned and to avoid duplicate allocation, IANA is requested to provide a method to register and query the following information: o The YANG module name o The contact information of the author o The specification reference o The associated ".yang" file(s) (Optional) o The associated ".sid" file (Optional) Registration of YANG modules is optional. When a YANG module is registered, the registrant MUST provide the module name and contact information and/or a specification reference. The registration of the associated ".yang" and ".sid" files is optional. When provided, the validity of the files MUST be verified. This can be accomplished by a YANG validation tool specially modified to support ".sid" file verification. The SID range specified within the ".sid" file SHOULD also be checked against the "SID" range registry (Section 7.1) and against the other YANG modules registered to detect any duplicate use of SIDs. Initial entries in this registry are as follows: +-------------+------+-----------------+---------------------------+ | Entry Point | Size | Module name | Reference | +-------------+------+-----------------+---------------------------+ | 1000 | 100 | ietf-cool | [I-D.veillette-core-cool] | | 1100 | 400 | iana-if-type | [RFC7224] | | 1500 | 100 | ietf-interfaces | [RFC7223] | | 1600 | 100 | ietf-ip | [RFC7277] | | 1700 | 100 | ietf-system | [RFC7317] | +-------------+------+-----------------+---------------------------+ 8. Acknowledgments The authors would like to thank Carsten Bormann for his help during the development of this document and his useful comments during the review process. Somaraju, et al. Expires January 9, 2017 [Page 11] Internet-Draft Structure Identifier (SID) July 2016 9. References 9.1. Normative References [I-D.ietf-netmod-rfc6020bis] Bjorklund, M., "The YANG 1.1 Data Modeling Language", draft-ietf-netmod-rfc6020bis-14 (work in progress), June 2016. [I-D.ietf-netmod-yang-json] Lhotka, L., "JSON Encoding of Data Modeled with YANG", draft-ietf-netmod-yang-json-10 (work in progress), March 2016. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049, October 2013, . 9.2. Informative References [I-D.veillette-core-cool] Veillette, M., Pelov, A., Somaraju, A., Turner, R., and A. Minaburo, "Constrained Objects Language", draft-veillette- core-cool-01 (work in progress), March 2016. [RFC7223] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 7223, DOI 10.17487/RFC7223, May 2014, . [RFC7224] Bjorklund, M., "IANA Interface Type YANG Module", RFC 7224, DOI 10.17487/RFC7224, May 2014, . [RFC7277] Bjorklund, M., "A YANG Data Model for IP Management", RFC 7277, DOI 10.17487/RFC7277, June 2014, . [RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for System Management", RFC 7317, DOI 10.17487/RFC7317, August 2014, . Somaraju, et al. Expires January 9, 2017 [Page 12] Internet-Draft Structure Identifier (SID) July 2016 Appendix A. ".sid" file example The following .sid file (ietf-system@2014-08-06.sid) have been generated using the following yang modules: o ietf-system@2014-08-06.yang o ietf-yang-types@2013-07-15.yang o ietf-inet-types@2013-07-15.yang o ietf-netconf-acm@2012-02-22.yang o iana-crypt-hash@2014-04-04.yang { "assignment-ranges": [ { "entry-point": 1700, "size": 100 } ], "module-name": "ietf-system", "module-revision": "2014-08-06", "items": [ { "type": "Module", "label": "ietf-system", "sid": 1700 }, { "type": "feature", "label": "authentication", "sid": 1701 }, { "type": "feature", "label": "dns-udp-tcp-port", "sid": 1702 }, { "type": "feature", "label": "local-users", "sid": 1703 }, { "type": "feature", "label": "ntp", Somaraju, et al. Expires January 9, 2017 [Page 13] Internet-Draft Structure Identifier (SID) July 2016 "sid": 1704 }, { "type": "feature", "label": "ntp-udp-port", "sid": 1705 }, { "type": "feature", "label": "radius", "sid": 1706 }, { "type": "feature", "label": "radius-authentication", "sid": 1707 }, { "type": "feature", "label": "timezone-name", "sid": 1708 }, { "type": "identity", "label": "/authentication-method", "sid": 1709 }, { "type": "identity", "label": "/authentication-method/local-users", "sid": 1710 }, { "type": "identity", "label": "/authentication-method/radius", "sid": 1711 }, { "type": "identity", "label": "/radius-authentication-type", "sid": 1712 }, { "type": "identity", "label": "/radius-authentication-type/radius-chap", "sid": 1713 }, { Somaraju, et al. Expires January 9, 2017 [Page 14] Internet-Draft Structure Identifier (SID) July 2016 "type": "identity", "label": "/radius-authentication-type/radius-pap", "sid": 1714 }, { "type": "node", "label": "/system", "sid": 1715 }, { "type": "node", "label": "/system-state", "sid": 1716 }, { "type": "node", "label": "/system-state/clock", "sid": 1717 }, { "type": "node", "label": "/system-state/clock/boot-datetime", "sid": 1718 }, { "type": "node", "label": "/system-state/clock/current-datetime", "sid": 1719 }, { "type": "node", "label": "/system-state/platform", "sid": 1720 }, { "type": "node", "label": "/system-state/platform/machine", "sid": 1721 }, { "type": "node", "label": "/system-state/platform/os-name", "sid": 1722 }, { "type": "node", "label": "/system-state/platform/os-release", "sid": 1723 Somaraju, et al. Expires January 9, 2017 [Page 15] Internet-Draft Structure Identifier (SID) July 2016 }, { "type": "node", "label": "/system-state/platform/os-version", "sid": 1724 }, { "type": "node", "label": "/system/authentication", "sid": 1725 }, { "type": "node", "label": "/system/authentication/user", "sid": 1726 }, { "type": "node", "label": "/system/authentication/user-authentication-order", "sid": 1727 }, { "type": "node", "label": "/system/authentication/user/authorized-key", "sid": 1728 }, { "type": "node", "label": "/system/authentication/user/authorized-key/algorithm", "sid": 1729 }, { "type": "node", "label": "/system/authentication/user/authorized-key/key-data", "sid": 1730 }, { "type": "node", "label": "/system/authentication/user/authorized-key/name", "sid": 1731 }, { "type": "node", "label": "/system/authentication/user/name", "sid": 1732 }, { "type": "node", Somaraju, et al. Expires January 9, 2017 [Page 16] Internet-Draft Structure Identifier (SID) July 2016 "label": "/system/authentication/user/password", "sid": 1733 }, { "type": "node", "label": "/system/clock", "sid": 1734 }, { "type": "node", "label": "/system/clock/timezone/timezone-name/timezone-name", "sid": 1735 }, { "type": "node", "label": "/system/clock/timezone/timezone-utc-offset/timezone-utc-offset", "sid": 1736 }, { "type": "node", "label": "/system/contact", "sid": 1737 }, { "type": "node", "label": "/system/dns-resolver", "sid": 1738 }, { "type": "node", "label": "/system/dns-resolver/options", "sid": 1739 }, { "type": "node", "label": "/system/dns-resolver/options/attempts", "sid": 1740 }, { "type": "node", "label": "/system/dns-resolver/options/timeout", "sid": 1741 }, { "type": "node", "label": "/system/dns-resolver/search", "sid": 1742 }, Somaraju, et al. Expires January 9, 2017 [Page 17] Internet-Draft Structure Identifier (SID) July 2016 { "type": "node", "label": "/system/dns-resolver/server", "sid": 1743 }, { "type": "node", "label": "/system/dns-resolver/server/name", "sid": 1744 }, { "type": "node", "label": "/system/dns-resolver/server/transport/udp-and-tcp/udp-and-tcp", "sid": 1745 }, { "type": "node", "label": "/system/dns-resolver/server/transport/udp-and-tcp/udp-and-tcp/address", "sid": 1746 }, { "type": "node", "label": "/system/dns-resolver/server/transport/udp-and-tcp/udp-and-tcp/port", "sid": 1747 }, { "type": "node", "label": "/system/hostname", "sid": 1748 }, { "type": "node", "label": "/system/location", "sid": 1749 }, { "type": "node", "label": "/system/ntp", "sid": 1750 }, { "type": "node", "label": "/system/ntp/enabled", "sid": 1751 }, { "type": "node", "label": "/system/ntp/server", Somaraju, et al. Expires January 9, 2017 [Page 18] Internet-Draft Structure Identifier (SID) July 2016 "sid": 1752 }, { "type": "node", "label": "/system/ntp/server/association-type", "sid": 1753 }, { "type": "node", "label": "/system/ntp/server/iburst", "sid": 1754 }, { "type": "node", "label": "/system/ntp/server/name", "sid": 1755 }, { "type": "node", "label": "/system/ntp/server/prefer", "sid": 1756 }, { "type": "node", "label": "/system/ntp/server/transport/udp/udp", "sid": 1757 }, { "type": "node", "label": "/system/ntp/server/transport/udp/udp/address", "sid": 1758 }, { "type": "node", "label": "/system/ntp/server/transport/udp/udp/port", "sid": 1759 }, { "type": "node", "label": "/system/radius", "sid": 1760 }, { "type": "node", "label": "/system/radius/options", "sid": 1761 }, { Somaraju, et al. Expires January 9, 2017 [Page 19] Internet-Draft Structure Identifier (SID) July 2016 "type": "node", "label": "/system/radius/options/attempts", "sid": 1762 }, { "type": "node", "label": "/system/radius/options/timeout", "sid": 1763 }, { "type": "node", "label": "/system/radius/server", "sid": 1764 }, { "type": "node", "label": "/system/radius/server/authentication-type", "sid": 1765 }, { "type": "node", "label": "/system/radius/server/name", "sid": 1766 }, { "type": "node", "label": "/system/radius/server/transport/udp/udp", "sid": 1767 }, { "type": "node", "label": "/system/radius/server/transport/udp/udp/address", "sid": 1768 }, { "type": "node", "label": "/system/radius/server/transport/udp/udp/authentication-port", "sid": 1769 }, { "type": "node", "label": "/system/radius/server/transport/udp/udp/shared-secret", "sid": 1770 }, { "type": "rpc", "label": "/set-current-datetime", "sid": 1771 Somaraju, et al. Expires January 9, 2017 [Page 20] Internet-Draft Structure Identifier (SID) July 2016 }, { "type": "rpc", "label": "/set-current-datetime/input/current-datetime", "sid": 1772 }, { "type": "rpc", "label": "/system-restart", "sid": 1773 }, { "type": "rpc", "label": "/system-shutdown", "sid": 1774 } ] } Authors' Addresses Abhinav Somaraju (editor) Tridonic GmbH & Co KG Farbergasse 15 Dornbirn, Vorarlberg 6850 Austria Phone: +43664808926169 Email: abhinav.somaraju@tridonic.com Michel Veillette (editor) Trilliant Networks Inc. 610 Rue du Luxembourg Granby, Quebec J2J 2V2 Canada Phone: +14503750556 Email: michel.veillette@trilliantinc.com Alexander Pelov Acklio 2bis rue de la Chataigneraie Cesson-Sevigne, Bretagne 35510 France Email: a@ackl.io Somaraju, et al. Expires January 9, 2017 [Page 21] Internet-Draft Structure Identifier (SID) July 2016 Randy Turner Landis+Gyr 30000 Mill Creek Ave Suite 100 Alpharetta, GA 30022 US Phone: ++16782581292 Email: randy.turner@landisgyr.com URI: http://www.landisgyr.com/ Ana Minaburo Acklio 2bis rue de la chataigneraie Cesson-Sevigne, Bretagne 35510 France Email: ana@ackl.io Somaraju, et al. Expires January 9, 2017 [Page 22]