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Information-Centric Networking (ICN): CCN and NDN Terminology
draft-irtf-icnrg-terminology-01

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This is an older version of an Internet-Draft that was ultimately published as RFC 8793.
Authors Bastiaan Wissingh, Christopher A. Wood , Alex Afanasyev , Lixia Zhang , David R. Oran , Christian Tschudin
Last updated 2018-10-22 (Latest revision 2017-12-25)
Replaces draft-wissingh-icnrg-terminology
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draft-irtf-icnrg-terminology-01
icnrg                                                        B. Wissingh
Internet-Draft                                                       TNO
Intended status: Informational                                   C. Wood
Expires: April 25, 2019                  University of California Irvine
                                                            A. Afanasyev
                                        Florida International University
                                                                L. Zhang
                                                                    UCLA
                                                                 D. Oran
                                       Network Systems Research & Design
                                                             C. Tschudin
                                                     University of Basel
                                                        October 22, 2018

     Information-Centric Networking (ICN): CCN and NDN Terminology
                    draft-irtf-icnrg-terminology-01

Abstract

   Information Centric Networking (ICN) is a new paradigm where network
   communications are accomplished by requesting named content, instead
   of sending packets to destination addresses.  Named Data Networking
   (NDN) and Content-Centric Networking (CCN) are two prominent ICN
   architectures.  This document provides an overview of the terminology
   and definitions that have been used in describing concepts in these
   two projects.  While there are other ICN architectures, they are not
   part of the NDN and CCN vision and as such are out of scope for this
   document.

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 https://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 April 25, 2019.

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Copyright Notice

   Copyright (c) 2018 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
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   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.  A Sketch of the Big Picture of ICN  . . . . . . . . . . . . .   3
   3.  Terms by category . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  Generic terms . . . . . . . . . . . . . . . . . . . . . .   5
     3.2.  Terms related to ICN Nodes  . . . . . . . . . . . . . . .   6
     3.3.  Terms related to the Forwarding plane . . . . . . . . . .   7
     3.4.  Terms related to Packet Types . . . . . . . . . . . . . .   9
     3.5.  Terms related to Name Types . . . . . . . . . . . . . . .  11
     3.6.  Terms related to Name Usage . . . . . . . . . . . . . . .  12
     3.7.  Terms related to Data-Centric Security  . . . . . . . . .  13
     3.8.  Uncategorized terms . . . . . . . . . . . . . . . . . . .  14
   4.  Semantics and Usage . . . . . . . . . . . . . . . . . . . . .  15
     4.1.  Data Transfer . . . . . . . . . . . . . . . . . . . . . .  15
     4.2.  Data Transport  . . . . . . . . . . . . . . . . . . . . .  15
     4.3.  Lookup Service  . . . . . . . . . . . . . . . . . . . . .  15
     4.4.  Database Access . . . . . . . . . . . . . . . . . . . . .  15
     4.5.  Remote Procedure Call . . . . . . . . . . . . . . . . . .  15
   5.  Informational References  . . . . . . . . . . . . . . . . . .  16
   Appendix A.  Acknowledgments  . . . . . . . . . . . . . . . . . .  18
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  18

1.  Introduction

   Information-centric networking (ICN) is an approach to evolve the
   Internet infrastructure from the existing host-centric design to a
   data-centric architecture, where accessing data by name becomes the
   essential network primitive.  The goal is to let applications refer
   to data independently of their location or means of transportation,
   which enables native multicast delivery, ubiquitous in-network
   caching and replication of data objects.

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   As the work on this topic continues to evolve, many new terms are
   emerging over time.  The goal of this document is to provide a
   thorough collection of these terms with a corresponding definition as
   they are used in the CCNx and NDN projects.  Other ICN projects such
   as NetInf, or MobilityFirst are not covered and will be the subject
   of other documents.

   To help provide context for the individual terms to be defined, in
   this draft we first sketch the bigger picture of an ICN network by
   introducing the basic concepts and identifying the major components
   of the architecture in Section 2, after which in Section 3 ICN
   related terms are listed by different categories.

2.  A Sketch of the Big Picture of ICN

   In networking terms, an ICN is a delivery infrastructure for named
   data.  For other, complementing views see Section 4.

         requestor         zero or more           data sources or
         (node)          forwarding nodes         replica nodes
           |                 | ... |                  |...|
           |   Interest(n)   |     |   Interest(n)    |   |
           | --------------> |     | ---------------> |   |
           |                 |     | -------------------> |
           |                 |     |                  |   |
           |                 |     |  Data([n],c,[s]) |   |
           |                 |     | <--------------- |   |
           |                 |     | <------------------- |
           | Data([n],c,[s]) |     |                  |   |
           | <-------------- |     |                  |   |

   Figure 1: Request-Reply Protocol of ICN networking.  Legend: n=name,
                          c=content, s=signature.

   The following list describes the basic ICN concepts needed to discuss
   the implementation of this service abstraction.

   *Request-Reply Protocol (Interest and Data Packet)*:

      An ICN's lookup service is implemented by defining two types of
      network packet formats: Interest packets that request content by
      name, and Data packets that carry the requested content.  The
      returned Data packet must match the request's parameters (e.g.,
      having a partially or fully matching name).  If the request is
      ambiguous and several Data packets would satisfy the request, the
      ICN network returns only one matching Data packet (flow balance
      between Interest and Data packets over individual links).

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   *Packet and Content Names*

      Without an irrefutable binding between a name of a Data packet and
      its content, Data packet names would be useless for fetching
      specific content.  In ICN, verification of a Data packet's name-
      to-content binding is achieved through cryptographic means, either
      by (1) a cryptographic signature that explicitly binds an
      application-chosen name to a Data packet's content, or (2) relying
      on an implicit name (cryptographic hash of the Data packet with or
      without application-chosen name) that the data consumer obtained
      through other means.

   *Data Authenticity and Encryption*:

      Any data consumer and network element can validate the
      authenticity of a Data packet by verifying its cryptographic name-
      to-content binding.  In contrast, whether a Data packet's content
      (payload) itself is encrypted or not is irrelevant to the ICN
      network.  The use and management of content encryption keys is an
      application-layer concern.

   *Trust*:

      Data authenticity is distinct from data trustworthiness, though
      the two concepts are related.  A packet is authentic if it has a
      valid name-to-content binding.  A packet is trustworthy, i.e., it
      comes from a reputable or trusted origin, if this binding is valid
      in the context of a trust model.

   *Segmenting and Versioning*:

      An ICN network will be engineered for some packet size limit.  As
      application-level data objects will often be considerably larger,
      objects must be segmented into multiple Data packets.  The names
      for these Data packets can, for example, be constructed by
      choosing one application-level object name to which a different
      suffix is added for each segment.  The same method can be used to
      handle different versions of an application-level object by
      including a version number into the name of the overall object.

   *Packet and Frame*:

      NDN and CCNx introduce Protocol Data Units (PDUs) which typically
      are larger than the maximum transmission unit of the underlying
      networking technology.  We refer to PDUs as 'packets' and the
      (potentially fragmented) packet parts that traverse MTU-bound
      links as 'frames'.  Handling link-layer technologies which lead to

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      fragmentation of ICN packets is done inside the ICN network and is
      not visible at the service interface.

   *ICN Node*:

      A node within an ICN network can fulfill the role of a data
      producer, a data consumer, and/or a forwarder for Interest and
      Data packets.  When a forwarder has connectivity to neighbor
      nodes, it performs Interest and Data packet forwarding in real
      time.  It can also behave like a packet mule, that is it may carry
      an Interest or Data packet for some time before forwarding it to
      next node.  An ICN node may also run routing protocols to assist
      its Interest forwarding decisions.

                                      --> add ASCII art here
                                      (of a forwarding node
                                      and its PIT, FIB, CS)

              Figure 2: Structure of an ICN forwarding node.

   *Forwarding Plane*:

      The canonical way of implementing packet forwarding in an ICN
      network relies on three data structures that capture a node's
      state: a Forwarding Interest Table (FIB), a Pending Interest
      Table (PIT), and a Content Store (CS).  It also utilizes Interest
      forwarding strategies which takes input from both FIB and
      measurements to make Interest forwarding decisions.  When a node
      receives an Interest packet, it checks its CS and PIT to find a
      matching entry; if no match is found, the node records the
      Interest in its PIT and forwards the Interest to the next hop(s)
      towards the requested content based on the information in its FIB.

3.  Terms by category

3.1.  Generic terms

   *Information-Centric Networking (ICN)*:

      A networking architecture that retrieves Data packets as response
      to Interest packets.  Content-Centric Networking (CCNx 1.x) and
      Named Data Networking (NDN) are two realizations (designs) of the
      ICN architecture.

   *Data packet immutability*:

      After a data packet is created, it cannot change.  If the content
      carried in the data packet is mutable, versioning should be used,

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      so that each version uniquely identifies an immutable instance of
      the content.  This allows disambiguation of coordination in
      distributed systems.

3.2.  Terms related to ICN Nodes

   *ICN Interface*:

      A generalization of the network interface that can represent a
      physical network interface (ethernet, wifi, bluetooth adapter,
      etc.), an overlay inter-node channel (IP/UDP tunnel, etc.), or an
      intra-node IPC channel to an application (unix socket, shared
      memory, intents, etc.).

         Common aliases include: face.

   *ICN Consumer*:

      An ICN entity that requests Data packets by generating and sending
      out Interest packets towards local (using intra-node interfaces)
      or remote (using inter-node interfaces) ICN Forwarders.

         Common aliases include: consumer, information consumer, data
         consumer, consumer of the content.

   *ICN Producer*:

      An ICN entity that creates Data packets and makes them available
      for retrieval.

         Common aliases include: producer, publisher, information
         publisher, data publisher, data producer.

   *ICN Forwarder*:

      An ICN entity that implements stateful forwarding.

         Common aliases include: ICN router.

   *Data Mule*:

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      An ICN entity that temporarily stores and potentially carries an
      Interest or Data packet before forwarding it to next ICN entity.

3.3.  Terms related to the Forwarding plane

   *Stateful forwarding*:

      A forwarding process that records incoming Interest packets in the
      PIT and uses the recorded information to forward the retrieved
      Data packets back to the consumer(s).  The recorded information
      can also be used to measure data plane performance, e.g., to
      adjust interest forwarding strategy decisions.

         Common aliases include: ICN Data plane, ICN Forwarding.

   *Forwarding strategy*:

      A module of the ICN stateful forwarding (ICN data) plane that
      implements a decision on where/how to forward the incoming
      Interest packet.  The forwarding strategy can take input from the
      Forwarding Information Base (FIB), measured data plane performance
      parameters, and/or use other mechanisms to make the decision.

         Common aliases include: Interest forwarding strategy.

   *Upstream (forwarding)*:

      Forwarding packets in the direction of Interests (i.e., Interests
      are forwarded upstream): consumer, router, router, ..., producer.

   *Downstream (forwarding)*:

      Forwarding packets in the opposite direction of Interest
      forwarding (i.e., Data and Interest Nacks are forwarded
      downstream): producer, router, ..., consumer(s).

   *Interest forwarding*:

      A process of forwarding Interest packets using the Names carried
      in the Interests.  In case of Stateful forwarding, creating an
      entry in PIT.  The forwarding decision is made by the Forwarding
      Strategy.

   *Interest aggregation*:

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      A process of combining multiple identical Interest packets for the
      same Data into a single PIT entry.  Not the same as Interest
      suppresion.

         Common aliases include: Interest collapsing.

   *Data forwarding*:

      A process of forwarding the incoming Data packet to the
      interface(s) recorded in the corresponding PIT entry (entries) and
      removing the corresponding PIT entry (entries).

   *Satisfying an Interest*:

      An overall process of returning content that satisfies the
      constraints imposed by the Interest, most notably a match in the
      provided Name.

   *Pending Interest Table (PIT)*:

      A database that records received and not yet satisfied Interests
      with the interfaces from where they were received.  The PIT can
      also store interfaces to where Interests were forwarded, and
      information to assess data plane performance.  Interests for the
      same Data are aggregated into a single PIT entry.

   *Forwarding Information Base (FIB)*:

      A database that contains a set of prefixes, each prefix associated
      with one or more faces that can be used to retrieve Data packets
      with Names under the corresponding prefix.  The list of faces for
      each prefix can be ranked, and each face may be associated with
      additional information to facilitate forwarding strategy
      decisions.

   *Content Store (CS)*:

      A database in an ICN router that provides caching.

   *In-network storage*:

      An optional process of storing a Data packet within the network
      (opportunistic caches, dedicated on/off path caches, and managed
      in-network storage systems), so it can satisfy an incoming
      Interest for this Data packet.  The in-network storages can
      optionally advertise the stored Data packets in the routing plane.

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   *Opportunistic caching*:

      A process of temporarily storing a forwarded Data packet in the
      router's memory (RAM or disk), so it can be used to satisfy future
      Interests for the same Data, if any.

         Common aliases include: on-path in-network caching

   *Managed caching*:

      A process of temporarily, permanently, or scheduled storing of a
      selected (set of) Data packet(s).

         Common aliases include: off-path in-network storage

   *Managed in-network storage*:

      An entity acting as an ICN publisher that implements managed
      caching.

         Common aliases include: repository, repo

   *ICN Routing plane*:

      An ICN protocol or a set of ICN protocols to exchange information
      about Name space reachability.

   *ICN Routing Information Base (RIB)*:

      A database that contains a set of prefix-face mappings that are
      produced by running one or multiple routing protocols.  The RIB is
      used to populate the FIB.

3.4.  Terms related to Packet Types

   *Interest packet*:

      A network-level packet that expresses the request for a data
      packet using either an exact name or a name prefix.  An interest
      packet may optionally carry a set of additional restrictions
      (e.g., interest selectors).  An interest may be associated with
      additional information to facilitate forwarding and can include

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      Interest lifetime, hop limit, forwarding hints, labels, etc.  In
      different ICN designs, the set of additional associated
      information may vary.

         Common aliases include: interest, interest message, information
         request

   *Interest Nack*:

      A packet that contains the Interest packet and optional
      annotation, which is sent by the ICN Router to the interface(s)
      the Interest was received from.  Interest Nack is used to inform
      downstream ICN nodes about inability to forward the included
      Interest packet.  The annotation can describe the reason.

         Common aliases include: network NACK, Interest return.

   *Data packet*:

      A network-level packet that carries payload, uniquely identified
      by a name, and is directly secured.

         Common aliases include: data, data object, content object,
         content object packet, data message, named data object, named
         data.

   *Link*:

      A type of Data packet whose body contains the Name of another Data
      packet.  This inner Name is often a Full Name, i.e., it specifies
      the Packet ID of the corresponding Data packet, but this is not a
      requirement.

         Common aliases include: pointer.

   *Manifest*:

      A type of Data packet that contains Full Name Links to one or more
      Data Packets.  Manifests group collections of related Data packets
      under a single Name.  This has the additional benefit of

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      amortizing the signature verification cost for each Data packet
      referenced by the inner Links.  Manifests typically contain
      additional metadata, e.g., the size (in bytes) of each linked Data
      packet and the cryptographic hash digest of all Data contained in
      the linked Data packets.

3.5.  Terms related to Name Types

   *Name*:

      A Data packet identifier.  An ICN name is hierarchical (a sequence
      of name components) and usually is semantically meaningful, making
      it expressive, flexible and application-specific (akin to a HTTP
      URL).  A Name may encode information about application context,
      semantics, locations (topological, geographical, hyperbolic,
      etc.), a service name, etc.

         Common aliases include: data name, interest name, content name.

   *Name component*:

      A sequence of octets and optionally a numeric type representing a
      single label in the hierarchical structured name.

         Common aliases include: name segment (as in CCN).

   *Packet ID*:

      a unique cryptographic identifier for a Data packet.  Typically,
      this is a cryptographic hash digest of a data packet (such as
      SHA256), including its name, payload, meta information, and
      signature.

   *Selector*:

      A mechanism (condition) to select an individual Data packet from a
      collection of Data packets that match a given Interest that
      requests data using a prefix or exact Name.

         Common aliases include: interest selector, restrictor, interest
         restrictor.

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   *Nonce*:

      A field of an Interest packet that transiently 'names' an Interest
      instance (instance of Interest for a given name).

   *Exact Name*:

      A name that is encoded inside a Data packet and which typically
      uniquely identifies this Data packet.

   *Full Name*:

      An exact Name with the Packet ID of the corresponding Data packet.

   *Prefix Name*:

      A Name that includes a partial sequence of Name components
      (starting from the first one) of a Name encoded inside a Data
      packet.

         Common aliases include: prefix.

3.6.  Terms related to Name Usage

   *Naming conventions*:

      A convention, agreement, or specification for the Data packet
      naming.  Naming convention structures a namespace.

         Common aliases include: Naming scheme, ICN naming scheme,
         namespace convention

   *Hierarchically structured naming*:

      The naming scheme that assigns and interprets a Name as a sequence
      of labels (Name components) with hierarchical structure without an
      assumption of a single administrative root.  A structure provides
      useful context information for the Name.

         Common aliases include: hierarchical naming, structured naming.

   *Flat naming*:

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      The naming scheme that assigns and interprets a Name as a single
      label (Name component) without any internal structure.  This can
      be considered a special (or degenerated) case of structured names.

   *Segmentation*:

      A process of splitting large application content into a set of
      uniquely named data packets.  When using hierarchically structured
      names, each created data packet has a common prefix and additional
      component representing the segment (chunk) number.

         Common aliases include: chunking

   *Versioning*:

      A process of assigning a unique Name to the revision of the
      content carried in the Data packet.  When using a hierarchically
      structured Name, the version of the Data packet can be carried in
      a dedicated Name component (e.g., prefix identifies data, unique
      version component identifies the revision of the data).

   *Fragmentation*:

      A process of splitting data packets into frames so that they can
      be transmitted over the link with a smaller MTU size.

3.7.  Terms related to Data-Centric Security

   *Data-Centric Security*:

      A security property associated with the Data packet, including
      data (Data-Centric) integrity, authenticity, and optionally
      confidentiality.  These security properties stay with the data
      packet regardless where it is stored and how it is retrieved.

         Common aliases include: directly securing data packet

   *Data Integrity*

      A cryptographic mechanism to ensure the consistency of the Data
      packet bits.  The Data integrity property validates that the Data
      packet content has not been corrupted during transmission, e.g.,
      over lossy channels.

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   *Data Authenticity*

      A cryptographic mechanism to ensure trustworthiness of a Data
      packet, based on a selected (e.g., by a consumer/producer) trust
      model.  Typically, data authenticity is assured through the use of
      asymmetric cryptographic signatures (e.g., RSA, ECDSA), but can
      also be realized using symmetric signatures (e.g., HMAC) within
      trusted domains.

   *Data Confidentiality*

      A cryptographic mechanism to ensure secrecy of a Data packet.
      Data confidentiality includes separate mechanisms: content
      confidentiality and Name confidentiality

   *Content Confidentiality*

      A cryptographic mechanism to prevent an unauthorized party to get
      access to the plain-text payload of a Data packet.  Can be
      realized through encryption (symmetric, asymmetric, hybrid) and
      proper distribution of the decryption keys to authorized parties.

   *Name Confidentiality*

      A cryptographic mechanism to prevent an observer of Interest-Data
      exchanges (e.g., intermediate router) from gaining detailed meta
      information about the Data packet.  This mechanism can be realized
      using encryption (same as content confidentiality) or obfuscation
      mechanisms.

3.8.  Uncategorized terms

   *Route-By-Name Routing (RBNR)*

   *Lookup-By-Name Routing (LBNR)*

   *Bread-crumbs routing*

   *Replication-by-name*

   *Routing Locator Signing*

   *Location-independence*

   *Content based*

   *ICN API*

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   *Information Centric Delay Tolerant Network*

   *Located-Named-Data*

   *Sessionless*

4.  Semantics and Usage

   The terminology described above is the manifestation of intended
   semantics of NDN and CCN operations (what do we expect the network to
   do?).  In this section we summarize the most commonly proposed use
   cases and interpretations.

4.1.  Data Transfer

   The networking view of NDN and CCN is that the request/reply protocol
   implements a basic, unreliable data transfer service for single,
   named packets.

4.2.  Data Transport

   Data transfer can be turned into a data transport service for
   application-level objects by additional logic.  This transport logic
   must understand and construct the series of names needed to
   reassemble the segmented object.  Various flavors of transport can be
   envisaged (reliable, streaming, mailbox, etc)

4.3.  Lookup Service

   A more distributed systems view of the basic request/reply protocol
   is that NDN and CCN provide a distributed lookup service: Given a key
   value (=name), the service will return the corresponding value.

4.4.  Database Access

   The lookup service turns into a database access protocol by ...
   namespace design ... prefix standing for a collection ... The DB
   query expression must be encoded as a name.

4.5.  Remote Procedure Call

   More generally, ... parameters in the interest ... used e.g.,/ as
   command channel for remote control of neighbor routers.

   *Interest match in FIB (longest prefix match)*:

      A process of finding a FIB entry with the longest Name (in terms
      of Name components) that is a prefix of the specified Name.

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   *Interest match in PIT (exact match)*:

      A process of finding a PIT entry that stores the same Name as
      specified in the Interest (including Interest restrictions, if
      any).

   *Data match in PIT (all match)*:

      A process of finding (a set of) PIT entries that can be satisfied
      with the specified Data packet.

   *Interest match in CS (any match)*:

      A process of finding an entry in router's Content Store that can
      satisfy the specified Interest.

5.  Informational References

   [I-D.irtf-icnrg-ccnxmessages]
              Mosko, M., Solis, I., and C. Wood, "CCNx Messages in TLV
              Format", draft-irtf-icnrg-ccnxmessages-08 (work in
              progress), July 2018.

   [I-D.irtf-icnrg-ccnxsemantics]
              Mosko, M., Solis, I., and C. Wood, "CCNx Semantics",
              draft-irtf-icnrg-ccnxsemantics-09 (work in progress), June
              2018.

   [I-D.irtf-icnrg-disaster]
              Seedorf, J., Arumaithurai, M., Tagami, A., Ramakrishnan,
              K., and N. Blefari-Melazzi, "Research Directions for Using
              ICN in Disaster Scenarios", draft-irtf-icnrg-disaster-03
              (work in progress), February 2018.

   [RFC7476]  Pentikousis, K., Ed., Ohlman, B., Corujo, D., Boggia, G.,
              Tyson, G., Davies, E., Molinaro, A., and S. Eum,
              "Information-Centric Networking: Baseline Scenarios",
              RFC 7476, DOI 10.17487/RFC7476, March 2015,
              <http://www.rfc-editor.org/info/rfc7476>.

   [RFC7927]  Kutscher, D., Ed., Eum, S., Pentikousis, K., Psaras, I.,
              Corujo, D., Saucez, D., Schmidt, T., and M. Waehlisch,
              "Information-Centric Networking (ICN) Research
              Challenges", RFC 7927, DOI 10.17487/RFC7927, July 2016,
              <http://www.rfc-editor.org/info/rfc7927>.

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   [RFC7933]  Westphal, C., Ed., Lederer, S., Posch, D., Timmerer, C.,
              Azgin, A., Liu, W., Mueller, C., Detti, A., Corujo, D.,
              Wang, J., Montpetit, M., and N. Murray, "Adaptive Video
              Streaming over Information-Centric Networking (ICN)",
              RFC 7933, DOI 10.17487/RFC7933, August 2016,
              <http://www.rfc-editor.org/info/rfc7933>.

   [RFC7945]  Pentikousis, K., Ed., Ohlman, B., Davies, E., Spirou, S.,
              and G. Boggia, "Information-Centric Networking: Evaluation
              and Security Considerations", RFC 7945,
              DOI 10.17487/RFC7945, September 2016,
              <http://www.rfc-editor.org/info/rfc7945>.

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Appendix A.  Acknowledgments

   Mark Mosco, ...

Authors' Addresses

   Bastiaan Wissingh
   TNO

   EMail: bastiaan.wissingh@tno.nl

   Christopher A. Wood
   University of California Irvine

   EMail: woodc1@uci.edu

   Alex Afanasyev
   Florida International University

   EMail: aa@cs.fiu.edu

   Lixia Zhang
   UCLA

   EMail: lixia@cs.ucla.edu

   David Oran
   Network Systems Research & Design

   EMail: daveoran@orandom.net

   Christian Tschudin
   University of Basel

   EMail: christian.tschudin@unibas.ch

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