ICNRG                                                         D. Trossen
Internet-Draft                                                   C. Wang
Intended status: Informational                              S. Robitzsch
Expires: December 8, 2019                              InterDigital Inc.
                                                                 M. Reed
                                                             M. Al-Naday
                                                        Essex University
                                                           J. Riihijarvi
                                                             RWTH Aachen
                                                            June 6, 2019

           IP-based Services over ICN in 5G LAN Environments


   In this draft, we provide architecture and operations for enabling IP
   services over ICN over (5G-enabled) LAN environments.  Operations
   include ICN API to upper layers, HTTP over ICN, Service Proxy
   Operations, ICN Flow Management, Name Resolution, Mobility Handling,
   and Dual Stack Device Support.

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 December 8, 2019.

Copyright Notice

   Copyright (c) 2019 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

Trossen, et al.         Expires December 8, 2019                [Page 1]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   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 . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  5G Control Plane Services . . . . . . . . . . . . . . . .   5
     3.2.  HTTP-based Streaming  . . . . . . . . . . . . . . . . . .   6
   4.  5GLAN in 5G Next Generation Core Network Architecture . . . .   7
     4.1.  Realization in SDN Transport Networks . . . . . . . . . .  10
     4.2.  Realization in Other Transport Networks . . . . . . . . .  10
   5.  IP-based Services over ICN over 5GLAN . . . . . . . . . . . .  11
     5.1.  General Operations  . . . . . . . . . . . . . . . . . . .  13
     5.2.  ICN API to Upper Layers . . . . . . . . . . . . . . . . .  14
     5.3.  HTTP over ICN . . . . . . . . . . . . . . . . . . . . . .  15
       5.3.1.  General Mapping Procedures  . . . . . . . . . . . . .  15
       5.3.2.  Realizing Ad-Hoc Multicast Responses for HTTP . . . .  15
     5.4.  Service Proxy Operations  . . . . . . . . . . . . . . . .  16
     5.5.  ICN Flow Management . . . . . . . . . . . . . . . . . . .  17
     5.6.  NR Operations . . . . . . . . . . . . . . . . . . . . . .  17
     5.7.  Mobility Handling . . . . . . . . . . . . . . . . . . . .  17
     5.8.  Dual Stack Device Support . . . . . . . . . . . . . . . .  17
   6.  Deployment Considerations . . . . . . . . . . . . . . . . . .  18
   7.  Conclusion  . . . . . . . . . . . . . . . . . . . . . . . . .  19
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  19
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  19
   10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  19
   11. Informative References  . . . . . . . . . . . . . . . . . . .  19
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  22

1.  Introduction

   As discussed in [I-D.ravi-icnrg-5gc-icn], Information-Centric
   Networks (ICN) could be more easily implemented in a Local Area
   Network (LAN) environment.  In relation to 5G, this specifically
   would realize an ICN deployment without requiring integration of ICN
   capabilities into the 5G core network itself.

   In the currently defined 5G core network, 5GLAN capabilities are
   being introduced that provide a LAN abstraction to 5G endpoints,
   allowing for Ethernet packets to be sent across a 5G network,

Trossen, et al.         Expires December 8, 2019                [Page 2]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   therefore extending the provisioning of LAN capabilities from fixed
   and Wifi-based networks to cellular ones.

   Utilizing such ICN realization over 5GLAN, the objective of this
   draft is to propose an architecture to enable IP-based services over
   such ICN-over-LAN environment with the reference architectural
   discussions in the 5G core network 3GPP specifications [TS23.501]
   [TS23.502] forming the basis of our discussions.  This draft also
   complements work related to various ICN deployment opportunities
   explored in [I-D.irtf-icnrg-deployment-guidelines], where 5G
   technology is considered as one of the promising alternatives.  In
   that, ICN is used as an underlay technology to provide routing
   capabilities to IP-based services.

   Through such replacement of IP routing with ICN routing, we
   capitalize on several ICN capabilities:

   o  Edge Computing: Multi-access Edge Computing (MEC) is located at
      the edge of the network and aids several latency sensitive
      applications such as augmented and virtual reality (AR/VR), as
      well as the ultra reliable and low latency class (URLLC) of
      applications such as autonomous vehicles.  Enabling edge computing
      over an IP converged 5GC comes with the challenge of application
      level reconfiguration required to re-initialize a session whenever
      it is being served by a non-optimal service instance
      topologically.  In contrast, named-based networking, as considered
      by ICN, naturally supports service-centric networking, which
      minimizes network related configuration for applications and
      allows fast resolution for named service instances.  This
      opportunity is realized by interpreting IP-based services as
      transactions over an ICN routed network with flexible routing to
      the nearest execution point for said transaction.

   o  Edge Storage and Caching: A principal design feature of ICN is the
      secured content (or named data) object, which allows location
      independent data replication at strategic storage points in the
      network, or data dissemination through ICN routers by means of
      opportunistic caching.  These features benefit both real-time and
      non-real-time applications whenever there is spatial and temporal
      correlation among content accessed by these users, thereby
      advantageous to both high-bandwidth and low-latency applications
      such as conferencing, AR/VR, and non-real time applications such
      as Video-on-Demand (VOD) and IoT transactions.  This opportunity
      is realized by the transaction-based model of realizing IP-based
      service on top of an ICN routed network, where transaction results
      can be retrieved from a number of network locations.

Trossen, et al.         Expires December 8, 2019                [Page 3]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   o  Opportunistic Multicast: The vast majority of current Internet
      traffic is due to unicast delivery of relatively immutable content
      such as video or software to very large client groups.  This has
      resulted in large amount of redundancy in network traffic, as well
      as creating capacity bottlenecks both in the core network as well
      as the server infrastructure serving the content.  Technologies
      such as content delivery networks (CDNs) help to spread out the
      network load, but are complex to manage, have inherent limits in
      terms of how rapidly they can react to changing network and server
      conditions, and cannot fundamentally reduce the network overhead
      arising from redundant unicast streams.  Furthermore, CDNs
      traditionally only reach into Points-of-Presence (POP) within
      customer networks, therefore not reducing the load of transfer
      from said POP to the end customers in that edge network.  In
      contrast, ICN enables opportunistic multicast delivery of content.
      We realize this opportunity by automatically delivering responses
      to quasi-concurrent requests in a single lightweight multicast
      transmission over the L2 customer network, extending the reach of
      CDNs down to the end user.  Unlike traditional IP multicast, no
      setup time overhead is added and no per-flow state is required in
      the network.

   In this document, we first outline possible use cases, capitalizing
   on the aforementioned ICN capabilities before discussing the proposed
   extensions to 5G to support a cellular-based LAN connectivity before
   outlining our proposal to support IP-based services over an ICN-
   routed LAN connectivity in such 5G environments.

2.  Terminology

   Following are terminologies relevant to this draft:

      5G-NextGen Core (5GC): Refers to the new 5G core network
      architecture being developed by 3GPP, we specifically refer to the
      architectural discussions in [TS23.501] [TS23.502].

      5GLAN: Refers to the extensions to the new 5G core network
      architecture that provide LAN connectivity to 5G devices connected
      via, e.g., new 5G air interfaces.

      User Plane Function (UPF): UPF is the generalized logical data
      plane function with context of the UE PDU session.  UPFs can play
      many roles, such as, being a flow classifier, a PDU session
      anchoring point, or a branching point.

      Packet Data Network (PDN or DN): This refers to service networks
      that belong to the operator or third party offered as a service to
      the UE.

Trossen, et al.         Expires December 8, 2019                [Page 4]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

      Unified Data Management (UDM): Realizes unified data management
      for wireless, wireline and any other types of subscribers for M2M,
      IOT applications, etc.  UDM reports subscriber related vital
      information e.g. virtual edge region, list of location visits,
      sessions active etc.  UDM works as a subscriber anchor point so
      that means OSS/BSS systems will have centralized monitoring-of/
      access-to of the system to get/set subscriber information.

      Authentication Server Function (AUSF): Provides mechanism for
      unified authentication for subscribers related to wireless,
      wireline and any other types of subscribers such as M2M and IOT
      applications.  The functions performed by AUSF are similar to HSS
      with additional functionalities to related to 5G.

      Session Management Function (SMF): Performs session management
      functions for attached users equipment (UE) in the 5G Core.  SMF
      can thus be formed by leveraging the Control and User Plane
      Separation (CUPS) feature with control plane session management.

      Access Mobility Function (AMF): Perform access mobility management
      for attached user equipment (UE) to the 5G core network.  The
      function includes, network access stratus (NAS) mobility functions
      such as authentication and authorization.

      Application Function (AF): Helps with influencing the user plane
      routing state in 5GC considering service requirements.

      Network Slicing: This conceptualizes the grouping for a set of
      logical or physical network functions with its own or shared
      control, data and service plane to meet specific service

3.  Use Cases

3.1.  5G Control Plane Services

   We exemplify the need for chaining service functions at the level of
   a service name through a use case stemming from the current 3GPP
   Rel-16 work on Service Based Architecture (SBA) [TS29.500]
   [SBA-ENHANCEMENT].  In this work, mobile network control planes are
   proposed to be realized by replacing the traditional network function
   interfaces with a fully service-based one.  HTTP was chosen as the
   application layer protocol for exchanging suitable service requests
   [TS29.500].  With this in mind, the exchange between, say the 3GPP
   (Rel-15) defined Session Management Function (SMF) and the Access and
   Mobility management Function (AMF) in a 5G control plane is being
   described as a set of web service like requests which are in turn
   embedded into HTTP requests.  Hence, interactions in a 5G control

Trossen, et al.         Expires December 8, 2019                [Page 5]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   plane can be modelled based on service function chains where the
   relationship is between the specific (IP-based) service function
   endpoints that implement the necessary service endpoints in the SMF
   and AMF.  The service functions are exposed through URIs with work
   ongoing to define the used naming conventions for such URIs.

   This move from a network function model (in pre-Rel 15 systems of
   3GPP) to a service-based model is motivated through the proliferation
   of data center operations for mobile network control plane services.
   In other words, typical IT-based methods to service provisioning, in
   particular that of virtualization of entire compute resources, are
   envisioned to being used in future operations of mobile networks.
   Hence, operators of such future mobile networks desire to virtualize
   service function endpoints and direct (control plane) traffic to the
   most appropriate current service instance in the most appropriate
   (local) data centre, such data centre envisioned as being
   interconnected through a software-defined wide area network (SD-WAN).
   'Appropriate' here can be defined by topological or geographical
   proximity of the service initiator to the service function endpoint.
   Alternatively, network or service instance compute load can be used
   to direct a request to a more appropriate (in this case less loaded)
   instance to reduce possible latency of the overall request.  Such
   data center centric operation is extended with the trend towards
   regionalization of load through a 'regional office' approach, where
   micro data centers provide virtualizable resources that can be used
   in the service execution, creating a larger degree of freedom when
   choosing the 'most appropriate' service endpoint for a particular
   incoming service request.  This 5G control plane scenario capitalizes
   on the edge computing capabilities of ICN by allowing for fast
   redirections of HTTP-based transactions to the nearest control plane
   service realization within the distributed data centre of the 5G
   operator infrastructure.

3.2.  HTTP-based Streaming

   With the extensive use of "web technology", "distributed services"
   and availability of heterogeneous network, HTTP has effectively
   transitioned into the common transport or session layer for E2E and
   multi-hop communication across the web.  Assume clients that are
   consuming the same content (such as a TV program) and that this
   content has for each block (typically segments worth 2 seconds of
   content) a set of outstanding requests from its clients.  HTTP
   request and response used in media streaming services like HLS, use
   HTTP response for delivery of content.  In such scenarios, where
   semi-synchronous access to the same resource occurs (such as watching
   prominent videos over Netflix or similar platforms or live TV over
   HTTP), traffic grows linearly with the number of viewers since the
   HTTP-based server will provide an HTTP response to each individual

Trossen, et al.         Expires December 8, 2019                [Page 6]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   viewer.  To mitigate the load impact, operators often utilize IP
   multicast underneath HTTP (for live TV) to create fewer, multicast,
   streams; though this comes with the high flow setup and management
   cost.  This poses a significant burden on operators in terms of costs
   and on users in terms of likely degradation of quality.

   This problem is not limited to traditional TV broadcasting.  Consider
   a virtual reality use case where several users are joining a VR
   session at the same time, e.g., centered around a joint event.
   Hence, due to the temporal correlation of the VR sessions, we can
   assume that multiple requests are sent for the same content at any
   point, particularly when viewing angles of VR clients are similar or
   the same.  Due to availability of virtual functions and cloud
   technology, the actual end point from where content is delivered may
   change.  For this type of scenarios, the opportunistic multicast
   capability of ICN may be utilized to reduce overall load in the
   network, as well as on the server providing the HTTP responses.  The
   latter also allows constrained resources to serve a higher volume of
   demands and therefore incur a higher impact on traffic distribution
   in the network.

4.  5GLAN in 5G Next Generation Core Network Architecture

   In this section, for brevity purposes, we restrict the discussions to
   the 5G extensions currently studied in 3GPP to facilitate a
   distributed, cellular-based LAN connectivity to end users, based on
   the 5G next generation core network architecture.  For more
   information on the latter, we refer to [TS23.501] [TS23.502] as well
   as [I-D.ravi-icnrg-5gc-icn].

Trossen, et al.         Expires December 8, 2019                [Page 7]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

    +------+  +------+  +-----+   +-----+   +-----+   +-----+
    | NSSF |  | NEF  |  | NRF |   | PCF |   | UDM |   | AF  |
    +--o---+  +--o---+  +--o--+   +--o--+   +--o--+   +--o--+
  Nnssf|     Nnef|     Nnrf|     Npcf|     Nudm|      Naf|
          Nausf|          Namf|          Nsmf|
            +--o--+        +--o--+        +--o--+
            | AUSF|        | AMF |        | SMF |
            +-----+        +-+-+-+        +--+--+
                            /  |             |
                 +---------+   |             |
            N1  /              |N2         N4|  +-N9/Nx-+
        +------+               |             |  |       |
       /                       |             |  |       V
    +-+--+                +----+----+  N3  +-+--+-------+--+  N6  +----+
    | UE +----------------+  (R)AN  +------+      UPF      +----->+ DN |
    +----+                +---------+      +---------------+      +----+

      Figure 1: 5G Core Network with Vertical_LAN (5GLAN) Extensions

   Figure 1 shows the current 5G Core Network Architecture being
   discussed within the scope of the normative work addressing 5GLAN
   Type services in the 3GPP System Architecture Working Group 2 (3GPP
   SA2), referred formally as "5GS Enhanced support of Vertical and LAN
   Services" [SA2-5GLAN].  The goal of this work item is to provide
   distributed LAN-based connectivity between two or more terminals or
   User Equipment entities (UEs) connected to the 5G network.  The SMF
   (session management function) provides a registration and discovery
   protocol that allows UEs wanting to communicate via a relevant 5GLAN
   group towards one or more UEs also members of this 5GLAN group, to
   determine the suitable forwarding information after each UE
   previously registered suitable identifier information with the SMF
   responsible to manage the paths across UEs in a 5GLAN group.  UEs
   register and discover (obtain) suitable identifiers during the
   establishment of a Protocol Data Unit (PDU) Session or PDU Session
   Modification procedure.  Suitable identifier information, according
   to [SA2-5GLAN], are Ethernet MAC addresses as well as IP addresses
   (the latter is usually assigned during the session setup through the
   SMF, i.e., the session management function).

   The SMF that manages the path across UEs in a 5GLAN group, then
   establishes the suitable procedures to ensure the forwarding between
   the required UPFs (user plane functions) to ensure the LAN
   connectivity between the UEs (user equipments) provided in the
   original request to the SMF.  When using the N9 interface to the UPF,
   this forwarding will rely on a tunnel-based approach between the UPFs
   along the path, while the Nx interface uses path-based forwarding

Trossen, et al.         Expires December 8, 2019                [Page 8]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   between UPFs, while LAN-based forwarding is utilized between the
   final UPF and the UE (utilizing the N3 interface towards the
   destination UE).

   In the following, path-based forwarding is assumed, i.e., the usage
   of the Nx interface and the utilization of a path identifier for the
   end-to-end LAN communication.  Here, the path between the source and
   destination UPFs is encoded through a bitfield, provided in the
   packet header.  Each bit position in said bitfield represents a
   unique link in the network.  Upon receiving an incoming packet, each
   UPF inspects said bitfield for the presence of any local link that is
   being served by one of its output ports.  Such presence check is
   implemented via a simple binary AND and CMP operation.  If no link is
   being found, the packet is dropped.  Such bitfield-based path
   representation also allows for creating multicast relations in an ad
   hoc manner by combining two or more path identifiers through a binary
   OR operation.  Note that due to the assignment of a bit position to a
   link, path identifiers are bidirectional and can therefore be used
   for request/response communication without incurring any need for
   path computation on the return path.

   For sending a packet from one Layer 2 device (UE) connected to one
   UPF (via a RAN) to a device connected to another UPF, we provide the
   MAC address of the destination and perform a header re-write by
   providing the destination MAC address of the ingress UPF when sending
   from source device to ingress and placing the end destination MAC
   address in the payload.  Upon arrival at the egress UPF, after having
   applied the path-based forwarding between ingress and egress UPF, the
   end destination address is restored while the end source MAC is
   placed in the payload with the egress L2 forwarder one being used as
   the L2 source MAC for the link-local transfer.  At the end device (or
   proxy device), the end source MAC address is restored as the source
   MAC, providing an abstraction of a link-local L2 communication
   between the end source and destination devices.

         | Src MAC | Dst MAC |  pathID  |  NAME_ID  |  Payload  |

                    Figure 2: General Packet Structure

   For this end-to-end transfer, the general packet structure of
   Figure 2 is used.  The Name_ID field is being used for the ICN
   operations, while the payload contains the information related to the
   transaction-based flow management described in Section 5.6 and the

Trossen, et al.         Expires December 8, 2019                [Page 9]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   PATH_ID is the bitfield-based path identifier for the path-based

4.1.  Realization in SDN Transport Networks

   An emerging technology for Layer 2 forwarding that suits the 5GLAN
   architecture in Figure 1 is that of Software-Defined networking (SDN)
   [SDN-DEFINITION], which allows for programmatically forwarding
   packets at Layer 2.  Switch-based rules are being executed with such
   rules being populated by the SDN controller.  Rules can act upon so-
   called matching fields, as defined by the OpenFlow protocol
   specification [OpenFlowSwitch].  Those fields include Ethernet MAC
   addresses, IPv4/6 source and destination addresses and other well-
   known Layer 3 and even 4 transport fields.

   As shown in [Reed], efficient path-based forwarding can be realized
   in SDN networks by placing the aforementioned path identifiers into
   the IPv6 source/destination fields of a forwarded packet.  Utilizing
   the IPv6 source/destination fields allows for natively supporting 256
   links in a transport network.  Larger topologies can be supported by
   extension schemes but are left out of this paper for brevity of the
   presentation.  During network bootstrapping, each link at each switch
   is assigned a unique bitnumber in the bitfield.  In order to forward
   based on such bitfield path information, the SDN controller is
   instructed to insert a suitable wildcard matching rule into the SDN
   switch.  This wildcard at a given switch is defined by the bitnumber
   that has been assigned to a particular link at that switch during
   bootstrapping.  Wildcard matching as a generalization of longest
   prefix matching is natively supported by SDN-based switches since the
   OpenFlow v1.3 specification, efficiently implemented through TCAM
   based operations.  With that, SDN forwarding actions only depend on
   the switch-local number of output ports, while being able to
   transport any number of higher-layer flows over the same transport
   network without specific flow rules being necessary.  This results in
   a constant forwarding table size while no controller-switch
   interaction is necessary for any flow setup; only changes in
   forwarding topology (resulting in a change of port to bit number
   assignment) will require suitable changes of forwarding rules in

4.2.  Realization in Other Transport Networks

   Although we focus the methods in this draft on Layer 2 forwarding
   approaches and realization of IP-over-ICN over a 5G LAN enabled
   network, path-based transport networks can also be established as an
   overlay over otherwise Layer 2 networks.  For instance, the BIER (Bit
   Indexed Explicit Replication) [RFC8279] efforts within the Internet
   Engineer Task Force (IETF) establish such path-based forwarding

Trossen, et al.         Expires December 8, 2019               [Page 10]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   transport as an overlay over existing, e.g., MPLS networks.  The
   path-based forwarding identification is similar to the aforementioned
   SDN realization although the bitfield represents ingress/egress
   information rather than links along the path.

   Yet another transport network example is presented in [Khalili],
   utilizing flow aggregation over SDN networks.  The flow aggregation
   again results in a path representation that is independent from the
   specific flows traversing the network.

5.  IP-based Services over ICN over 5GLAN

Trossen, et al.         Expires December 8, 2019               [Page 11]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

                   |       Forwarding Network      |     .... Control
                   |  +--------------------------+ |
                   |  | .          NR          . | |     **** Data
                   |  +-.----------------------.-+ |
+--------------+   |    .                      .   |    +--------------+
|     App      |   |  +-.---------+  +---------.-+ |    |      App     |
+-----+----+---+   |  | . ******* |  | ******* . | |    +--------------+
|HTTP*|TCP*|IP.|   |  | . * UPF * |  | * UPF * . | |    |.IP|*TCP|*HTTP|
+----*+---*+--.+   |  +-.-*-----*-+  +-*-----*-.-+ |    +.--+*---+*----+
|ICN *    *   .|   |    . *     *      *     * .   |    |.   *    * ICN|
+----*----*---.+  +---+ . *     ********     * . +---+  +.---*----*----+
|L2  *    *   ....|RAN+.. *                  * ..+RAN|....   *    *    |
|    **********************                  **********************    |
+--------------+  +---+ . *                  * . +---+  +--------------+
                   |    . *                  * .   |
                   |  +-.-*-----+      +-----*-.+  |
                   +--| . *  RAN|------|RAN  * .|--+
                      +-.-*-----+      +-----*-.+
                        . *                  * .
                        . *******      ******* .
Legacy    Service       ....... *      * .......   Service
Device    Proxy               . *      * .         Proxy
+-----+ +-------------------+ . *      * . +-------------------+
|APP *| |    *********      | . *      * . |     **********    |
+----*+ +----*+      *      | . *      * . |     *       +*----+
|HTTP*| |HTTP*|*******      | . *      * . |     ********|*HTTP|
+----*+ +----*-+     *      | . *      * . |     *       +*----+
|TCP *| |TCP * |******      | . *      * . |     *******| * TCP|
+----*+ +----*--+   +*------+ . *      * . +-----*+   +---*----+  +-------+
|IP  *| |IP  *  |***|* ICN .| . *      * . |.ICN *|***|   *  IP|  | IP    |
+----*+ +----*--+---+*-----.+ . *      * . +.----*+---+---*----+  |Peering|
|L2  *| |    *   L2  *     .... *      * ....    *        *    |  |Network|
|    *********       ************      ***********        ************    |
+-----+ +-------------------+              +-------------------+  +-------+

              Figure 3: IP-based Services over ICN over 5GLAN

   Figure 3 shows the protocol layering for realizing IP-based protocols
   over an ICN over 5GLAN transport, assuming an end-to-end LAN
   connectivity provided by solutions such as 5GLAN.

   Note that such LAN connectivity can also be found in environments
   such as localized LAN-based deployments in smart cities, enterprises
   and others, with the UPF representing, e.g., an SDN switch (utilizing
   the methods outlined in Section 4.1).  Hence, the solutions described
   in this section also applies to those deployments.

Trossen, et al.         Expires December 8, 2019               [Page 12]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   Key to the approach is that Internet services are being interpreted
   as the main unit of transfer in the architecture shown in Figure 3.
   For this, any Internet service is treated as a Named Service
   Transaction (NST) which is in turn suitably routed over an ICN layer
   in one or more other devices.  As a result of this name-based
   interpretation of any Internet service, the protocol stack in end
   devices flattens to four layers with Internet services and ICN, with
   ICN acting as a name-based routing layer for all IP protocols
   implemented atop, with Layer 1 and 2 realizing the end-to-end packet
   forwarding outlined in Section 4 (over a 5G environment) or a general
   LAN environment provided through WiFi or fixed Ethernet technologies.

   The general ICN operations are presented in Section 5.1 before
   discussing the assumed (strawman) API to the ICN layer in
   Section 5.2, which is used in turn to define the mapping of HTTP
   transactions to operations at the ICN layer in Section 5.3 for the
   example of HTTP.  As explained in that section, the ICN layer uses an
   interaction with the NR to register and discover HTTP-based services
   for determining the suitable end-to-end packet forwarding

   Interfaces to legacy devices and peering networks are preserved
   through service proxy devices, which terminate a traditional Internet
   protocol stack communication and translate it into a resulting flat
   protocol transaction.  Termination here can be based on well-known
   port numbers for specific Internet protocols, ultimately falling back
   to the IP datagram service being the minimal service being mapped.
   The operations of said service proxy devices is described in
   Section 5.4.

   An important aspect of the architecture is the mapping of the end-to-
   end flow semantic established in many Internet services onto the flat
   protocol stack.  Section 5.5 outlines the flow management that exists
   between the end devices.

   The mapping of protocol identifiers onto ICN forwarding relations,
   i.e., the operations of the name resolver (NR), shown in Figure 3, is
   described in Section 5.6, followed by the procedures for handling
   mobility of service providers and consumers in Section 5.7.  Finally,
   the support for dual-stack devices, not requiring a service proxy
   device yet being able to also connect to existing IP routed networks,
   is described in Section 5.8.

5.1.  General Operations

   The semantics of our name-based routing is that of a publish-
   subscribe system over a name.  The intention to receive packets with
   a certain name is expressed through a subscription while sending

Trossen, et al.         Expires December 8, 2019               [Page 13]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   packets to a name is expressed through a publication.  The matching
   of a sender to a receiver is realized through NR in Figure 3.  The
   exact nature of the matching is defined through the semantics of the
   service and, therefore, through the nature of the name provided.  For
   instance, HTTP and raw IP services are matched to exactly one
   subscriber only, providing an anycast capability, while IP multicast
   services are matched against any subscriber (with the IP multicast
   address being the name).

   Structured names are used with the root specific to the (Internet)
   service name, such as URL, and therefore deriving the matching
   semantics directly from the name.

   The subscription to a name is realized through a registration
   protocol between end device and NR.  Hence, any end device exposing a
   certain Internet service registers the suitable name with the NR,
   which in turn stores reachability information that is suitable for
   path calculation between the ingress and egress L2 forwarders between
   which the communication eventually will take place.  In our current
   realization, we utilize shortest paths only although other link
   weights can be utilized for, e.g., delay-constrained and other

   In our realization, we use network domain unique host identifiers
   that are being assigned to end devices during the connectivity setup.
   Sending a packet of a given Internet service is realized through a
   discovery protocol, which returns a suitable pathID, i.e., the
   forwarding information between ingress and egress L2 forwarder, and
   the destination MAC address of the hosting end device.  It is this
   pathID and MAC address that is being used in the general packet
   structure of Figure 2 to forward the packet to the destination.

   To reduce latency in further communication, the forwarding
   information is locally cached at the end device, while the cached
   information is being maintained through path updates sent by the NR
   in case of hosting end devices having moved or de-registered,
   therefore avoiding stale forwarding information.

5.2.  ICN API to Upper Layers

   The operations of the ICN layer are exposed to upper layers in
   Figure 1 through the following API calls, being exemplary here for
   the further explanation of operations in the next sub-sections:

   o  conn = send(name, payload)

   o  send(conn, payload)

Trossen, et al.         Expires December 8, 2019               [Page 14]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   o  conn = receive(name, &payload)

   o  receive(conn, &payload)

   The first send() call is used for initiating a send operation to a
   name with a connection handle returned, while the second send() is
   used for return calls, using a connection parameters that is being
   received with the receive() call to an incoming connection or for
   subsequence outgoing calls after an initial request to a name has
   been made.  A return send() is being received at the other (client)
   side through the second receive() call where the conn parameter is
   obtained by the corresponding send() call for the outgoing call.
   With these API functions, we provide means for providing name-based
   transactions with return responses association provided natively.

   The conn parameter represents the bitfield used for path-based
   forwarding in the remote host case or the hash of the local MAC
   address in case of link-local connections.

5.3.  HTTP over ICN

5.3.1.  General Mapping Procedures

   To realize the flat device nature, Internet service layers, such as
   the HTTP protocol stack or the TCP protocol stack, will need to be
   adapted to run atop this new API, implementing the semantics of the
   respective Internet protocol through suitable transactions at the
   name level.  In the example of HTTP, the standard operations of DNS
   resolution for the server to be contacted and opening of a TCP socket
   are altogether replaced by a single send(FQDN, HTTP request) call,
   while the response will be sent by the server, which received the
   request through a receive(FQDN, &payload) call, using the returned
   conn parameter to send the response with the second send() API call.
   Note that the use of bidirectional pathIDs, no NR lookup is performed
   at the HTTP serving endpoint.

5.3.2.  Realizing Ad-Hoc Multicast Responses for HTTP

   The basis of a named service transaction allows to deliver the same
   HTTP responses to several requestees in efficient multicast (see
   [I-D.ietf-bier-multicast-http-response] for use cases in a BIER-based
   transport network environment).

   This opportunity is realized by sending the same payload (i.e., an
   HTTP response to the same resource across a number of pending
   requests) through a combination of several conn parameters received
   in the incoming requests via the receive() function.

Trossen, et al.         Expires December 8, 2019               [Page 15]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   What is required in the HTTP stack implementation is a logic to
   decide that two or more outstanding requests are possible to be
   served by one response.  For this, upon receiving an incoming
   request, the HTTP stack determines any outstanding request to the
   same resource.  'Same' here is defined as URI-specific combination of
   the request URI and URI-specific header fields, such as browsing
   agent or similar, called requestID in the following.

   Once such determination is made that two requests are relating to the
   same resource, i.e., are having the same request ID, the HTTP stack
   maintains a temporary mapping of the request ID to the respective
   conn parameters delivered by the receive() call.  Upon receiving the
   HTTP response from its application-level logic, the HTTP stack will
   generate the suitable send(conn, payload) call where the provided
   conn parameter is bitwise OR of all previously stored conn parameters
   received in the receive() call.  The ICN layer will recognize the use
   of those ad-hoc created conn parameters and set the destination MAC
   address in the general packet structure of Figure 2 to the Ethernet
   broadcast MAC address as the destination address, leading to sending
   the response to all end devices at the egress L2 forwarders to which
   the response will be forwarded based on the combined conn parameter.
   Alternatively, one could request IEEE assignment for a specific
   Ethernet multicast address for this scheme instead of using the
   broadcast address.  For the local end device to determine the
   relevance of the response received at the broadcast channel, the HTTP
   stack of the serving endpoint includes the aforementioned requestID
   into the payload of the packet (see Figure 2), while the originating
   endpoint maintains an internal table with the requestID of pending
   requests and its associated conn handle.  If no matching requestID is
   found, the packet is not being delivered to the ICN layer of the
   incoming device.  If a request is found, the ICN layer delivers the
   response via the receive() call, using the conn handle stored in the
   pending request table.  Note that this filtering mechanism can easily
   be implemented in hardware upon standardizing the appropriate payload
   and header fields.

5.4.  Service Proxy Operations

   The service proxy in Figure 3 serves the integration of legacy
   devices, i.e., with regular IP protocol stack, and the
   interconnection to IP-based peering networks.  It registers suitable
   identifiers with the NR to ensure the reception of (ICN) packets,
   while providing suitable protocol termination for the various
   supported protocols.  For instance, for HTTP, the service proxy
   towards the peering network will register a wildcard name to the NR
   to receive any HTTP request not destined to a network-locally
   registered FQDN, operating as an HTTP proxy towards the peering

Trossen, et al.         Expires December 8, 2019               [Page 16]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

5.5.  ICN Flow Management

   EDITOR NOTE: left for future draft updates.

5.6.  NR Operations

   The NR in Figure 3 combines the operations of the SMF and the PMF in
   5GLAN (see Figure 1), by allowing for registering IP protocol
   identifiers for discovery and subsequent path computation by
   resolving the destination(s) to a suitable pathID and destination MAC
   address for forwarding.  This will require extensions to the
   operations of the SMF to allow for such higher layer identifiers to
   be registered (and discovered), in addition to the already supported
   Ethernet and IP addresses.

5.7.  Mobility Handling

   EDITOR NOTE: left for future draft updates.

5.8.  Dual Stack Device Support

   Figure 3 outlines a protocol stack for the user equipment that
   realizes IP-based services on top of the proposed name-based routing
   layer as a single stack device.  However, [I-D.irtf-icnrg-icn-lte-4g]
   outlines the possibility of supporting dual-stack devices for 4G LTE
   networks by allowing IP as well as ICN protocol stacks to be deployed
   with the operation of IP and ICN based applications.
   [I-D.ravi-icnrg-5gc-icn] outlines the same dual-stack device
   realization for a 5G ICN realization.  For both environments, a
   convergence layer is described that selects the appropriate data path
   for each ICN or IP application, e.g., based on configuration per
   application (similar to selecting network interfaces such as WiFi
   over cellular).

   As a possible data path selection, [I-D.irtf-icnrg-icn-lte-4g] and
   [I-D.ravi-icnrg-5gc-icn] envision the realization of IP-over-ICN
   (Section 4.2 in [I-D.irtf-icnrg-icn-lte-4g]) in which the convergence
   layer would realize similar mapping functions as described in this
   draft.  Hence, we foresee the utilization of such dual-stack devices
   connected to an IP-based services over ICN over 5GLAN environment.
   When utilizing the service proxy, IP applications that are configured
   to use the IP data path only could still utilize the ICN-based
   forwarding in the network.  In that case, functionality such as the
   opportunistic multicast in Section 5.3.2 would only reach up to the
   service proxy with unicast traffic continuing along the data path
   towards the user equipment.

Trossen, et al.         Expires December 8, 2019               [Page 17]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

6.  Deployment Considerations

   The work in [I-D.irtf-icnrg-deployment-guidelines] outlines a
   comprehensive set of considerations related to the deployment of ICN.
   We now relate the solutions proposed in this draft to the two main
   aspects covered in the deployment considerations draft, namely the
   'deployment configuration' (covered in Section 3 of
   [I-D.irtf-icnrg-deployment-guidelines]) that is being realized and
   the 'deployment migration paths' (covered in Section 4 of
   [I-D.irtf-icnrg-deployment-guidelines]) that are being provided.

   The solutions proposed in this draft relate to those "deployment
   configuration" as follows:

   o  The realization of IP-based service on top of an ICN routing
      capabilities, as proposed in Section 5, follows the "ICN-as-an-
      Underlay" categorization, interpreting the ICN routing as an
      underlay to the IP services with the path-based forwarding being
      compatible with the 5GLAN forwarding capabilities currently
      discussed in 3GPP and therefore providing an underlay integration
      capability for the ICN forwarding used in the proposed solution.

   o  The deployment of 5GLAN based ICN capabilities can be realized
      following the "ICN-as-a-Slice" deployment configuration, i.e., the
      5GLAN connectivity is provided to a "vertical 5G customer" which
      in turn provides the ICN capability over 5GLAN within said network
      (and compute) slice at the endpoints of the 5GLAN connectivity, as
      proposed in Section 3.

   In relation of the 'deployment migration paths', the solutions in
   this draft relate as follows:

   o  The integration with the 5GLAN capability, as proposed in
      Section 5, facilitates "edge network migration" (interpreting the
      cellular sub-system here as an edge network albeit a possibly
      geographically large one.

   o  The single stack realization, as proposed in Figure 3, as well as
      the dual-stack deployment, as proposed in Section 5.8, facilitate
      "application and services migration" through not only supporting
      ICN applications but also IP-based applications through the
      proposed IP-over-ICN mapping in the terminal.

   o  The IP over ICN over 5GLAN deployment, possibly combined with an
      ICN-as-a-Slice deployment, facilitates the "content delivery
      networks migration" through a deployment of IP-over-ICN-based
      5GLAN connected CDN elements in (virtualized) edge network nodes
      or POP locations in the customer (5G) network.

Trossen, et al.         Expires December 8, 2019               [Page 18]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

7.  Conclusion

   In this draft, we explored the feasibility of enabling IP services
   directly over ICN network over (5G)LAN environments.  We proposed the
   architecture and discussed corresponding operations of mapping IP-
   based services onto name-based transactions, with the specific
   example of HTTP-based transactions.  We described the flow
   management, the realization of opportunistic multicast responses for
   HTTP as well as the realization of dual-stack user equipment.  Future
   updates to the draft will provide more details to the flow management
   in terms of reliable transport between IP-over-ICN enabled end-
   systems as well as mobility handling.  We also described the
   deployment scenario for supporting IP services over ICN over 5GLAN.

8.  IANA Considerations

   This document requests no IANA actions.

9.  Security Considerations

   Editor Note: to be added in future drafts.

10.  Acknowledgments

   Work towards developing the solutions outlined in this draft have
   been funded under grants of the [H2020POINT] and [H2020FLAME]

11.  Informative References

              H2020, "The FLAME Project", https://www.ict-flame.eu/ .

              H2020, "The POINT Project", https://www.point-h2020.eu/ .

              Galis, A., Makhijani, K., Yu, D., and B. Liu, "Autonomic
              Slice Networking", draft-galis-anima-autonomic-slice-
              networking-05 (work in progress), September 2018.

              Purkayastha, D., Rahman, A., Trossen, D., and T. Eckert,
              "Applicability of BIER Multicast Overlay for Adaptive
              Streaming Services", draft-ietf-bier-multicast-http-
              response-00 (work in progress), February 2019.

Trossen, et al.         Expires December 8, 2019               [Page 19]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

              Rahman, A., Trossen, D., Kutscher, D., and R. Ravindran,
              "Deployment Considerations for Information-Centric
              Networking (ICN)", draft-irtf-icnrg-deployment-
              guidelines-06 (work in progress), May 2019.

              suthar, P., Stolic, M., Jangam, A., Trossen, D., and R.
              Ravindran, "Native Deployment of ICN in LTE, 4G Mobile
              Networks", draft-irtf-icnrg-icn-lte-4g-03 (work in
              progress), March 2019.

              Muscariello, L., Carofiglio, G., Auge, J., and M.
              Papalini, "Hybrid Information-Centric Networking", draft-
              muscariello-intarea-hicn-01 (work in progress), December

              Ravindran, R., suthar, P., Trossen, D., Wang, C., and G.
              White, "Enabling ICN in 3GPP's 5G NextGen Core
              Architecture", draft-ravi-icnrg-5gc-icn-04 (work in
              progress), May 2019.

              White, G., Shannigrahi, S., and C. Fan, "Internet Protocol
              Tunneling over Content Centric Mobile Networks", draft-
              white-icnrg-ipoc-01 (work in progress), June 2018.

   [Khalili]  Khalili, R., Poe, W., Despotovic, Z., and A. Hecker,
              "Reducing State of SDN Switches in Mobile Core Networks by
              Flow Rule Aggregation", IEEE ICCCN 2016, Hawaii, USA,
              August 2016.

              Open Networking Foundation, available at
              openflow-switch-v1.5.1.pdf, "OpenFlow Switch Specification
              V1.5.1", 2018.

   [Reed]     Reed, M., AI-Naday, M., Thomos, N., Trossen, D.,
              Petropoulos, G., and S. Spirou, "Stateless Multicast
              Switching in Software Defined Networks", IEEE ICC 2016,
              Kuala Lumpur, Maylaysia, 2016.

Trossen, et al.         Expires December 8, 2019               [Page 20]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   [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,

   [RFC8279]  Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
              Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
              Explicit Replication (BIER)", RFC 8279,
              DOI 10.17487/RFC8279, November 2017,

              3gpp-5glan, "SP-181129, Work Item Description,
              Vertical_LAN(SA2), 5GS Enhanced Support of Vertical and
              LAN Services", 3GPP ,

              3gpp-sba-enhancement, "S2-182904, New SID for Enhancements
              to the Service-Based 5G System Architecture.", 3GPP ,
              February 2018 (http://www.3gpp.org/ftp/tsg_sa/WG2_Arch/TSG

              Open Networking Foundation, available at
              https://www.opennetworking.org/sdn-definition/, "Software-
              Defined Networking (SDN) Definition", 2018.

              3gpp-23.501, "Technical Specification Group Services and
              System Aspects; System Architecture for the 5G System;
              Stage 2 (Rel.15)", 3GPP , December 2018.

              3gpp-23.502, "Technical Specification Group Services and
              System Aspects; Procedures for the 5G System; Stage 2
              (Rel. 15)", 3GPP , January 2019.

              3gpp-29.500, "Technical Realization of Service Based
              Architecture.", 3GPP , January 2018.

Trossen, et al.         Expires December 8, 2019               [Page 21]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

Authors' Addresses

   Dirk Trossen
   InterDigital Inc.
   64 Great Eastern Street, 1st Floor
   London  EC2A 3QR
   United Kingdom

   Email: Dirk.Trossen@InterDigital.com
   URI:   http://www.InterDigital.com/

   Chonggang Wang
   InterDigital Inc.
   1001 E Hector St, Suite 300
   Conshohocken  PA 19428
   United States

   Email: Chonggang.Wang@InterDigital.com
   URI:   http://www.InterDigital.com/

   Sebastian Robitzsch
   InterDigital Inc.
   64 Great Eastern Street, 1st Floor
   London  EC2A 3QR
   United Kingdom

   Email: Sebastian.Robitzsch@InterDigital.com
   URI:   http://www.InterDigital.com/

   Martin Reed
   Essex University
   United Kingdom

   Email: mjreed@essec.ac.uk
   URI:   https://www.essex.ac.uk/people/reedm58703/martin-reed

   Mays Al-Naday
   Essex University
   United Kingdom

   Email: mfhaln@essec.ac.uk
   URI:   https://www.essex.ac.uk/people/alned81405/mays-al-naday

Trossen, et al.         Expires December 8, 2019               [Page 22]

Internet-Draft            IP over ICN in 5GLAN                 June 2019

   Janne Riihijarvi
   RWTH Aachen

   Email: jariihij@googlemail.com
   URI:   https://www.inets.rwth-aachen.de/about-us/janne-riihijaervi/

Trossen, et al.         Expires December 8, 2019               [Page 23]