ICN Research Group                                          R. Ravindran
Internet-Draft                                            A. Chakraborti
Intended status: Informational                                  A. Azgin
Expires: May 20, 2017                                Huawei Technologies
                                                       November 16, 2016


                Forwarding-Label support in CCN Protocol
                draft-ravi-icnrg-ccn-forwarding-label-00

Abstract

   The objective of this proposal is to enable ID and Locator namespace
   split in the CCN protocol that has several applications such as
   towards Interest routing optimization, mobility, handling
   indirections in manifests, and routing scalability.  We enable this
   through the notion of forwarding-label (FL) object, which is an
   optional hop-by-hop payload in the Interest message with a locator
   name which identifies a network domain, router, or a host.  Depending
   on the application and trust context, an FL object can be subjected
   to policy based actions by the forwarders such as invoking security
   verification or enabling other service-centric actions such as FL
   object replacement.  FL object can be inserted by the applications or
   by the network.  To enable dynamic name resolution FL objects can
   also be modified in the network by designated points such as the edge
   routers.

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 May 20, 2017.








Ravindran, et al.         Expires May 20, 2017                  [Page 1]


Internet-Draft       Forwarding-label support in CCN       November 2016


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
   (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.  ID-Locator Namespace Split in CCN . . . . . . . . . . . . . .   2
   2.  Forwarding-Label Object Proposal  . . . . . . . . . . . . . .   4
     2.1.  FL Object Naming  . . . . . . . . . . . . . . . . . . . .   4
     2.2.  FL Object Insertion . . . . . . . . . . . . . . . . . . .   4
     2.3.  FL Object Swapping  . . . . . . . . . . . . . . . . . . .   5
     2.4.  FL Object Termination . . . . . . . . . . . . . . . . . .   5
   3.  FL Object Message Format  . . . . . . . . . . . . . . . . . .   6
   4.  FL Object Processing Rules  . . . . . . . . . . . . . . . . .   7
   5.  PIT Processing Implications . . . . . . . . . . . . . . . . .   8
   6.  Caching Implications  . . . . . . . . . . . . . . . . . . . .   9
   7.  Multiple Domain Scenario  . . . . . . . . . . . . . . . . . .   9
   8.  FL Object Security  . . . . . . . . . . . . . . . . . . . . .   9
   9.  Use Case Scenarios  . . . . . . . . . . . . . . . . . . . . .  10
     9.1.  Handling Producer Mobility  . . . . . . . . . . . . . . .  10
     9.2.  Manifests . . . . . . . . . . . . . . . . . . . . . . . .  11
     9.3.  Interest Routing Optimization . . . . . . . . . . . . . .  14
     9.4.  Routing Scalability . . . . . . . . . . . . . . . . . . .  14
   10. Informative References  . . . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15

1.  ID-Locator Namespace Split in CCN

   In the context of ICN/CCN, we define identifier and locator as
   follows:

   o  Identifier (ID) is a persistent secure or non-secure flat-ID or a
      hierarchical name assigned to a content, device or service.  If
      the ID is secure, then trust relationship can be derived from it.
      Generally the identifier space is managed by applications.





Ravindran, et al.         Expires May 20, 2017                  [Page 2]


Internet-Draft       Forwarding-label support in CCN       November 2016


   o  Locator (LID) is a routeable topological name assigned to a
      network entity such as a router, a server, or an end device.
      Generally the locator space is managed and assigned by the network
      administrators.

   We discuss here the motivations behind the need for separation
   between persistent name (ID) and a locator (LID) in the Interest
   message in the context of CCN and a proposal to achieve this.  The
   advantages of ID/Locator have been extensively studied and it has
   been part of many host-centric protocols such as HIP[2], ILNP [3],
   and LISP [4] and is also part of FIA architectures such as
   MobilityFirst[16].  Specifically in CCN, ID based routing is not
   efficient considering the need to dynamically replicate content and
   handle mobile entities, and the problem to address routing
   scalability [8].  Hence providing this distinct ID-LID separation in
   the protocol offers the following advantages:

   o  Today CCN applications bind to persistent IDs, while their
      resolution is handled through per-hop name-based routing by a CCN
      forwarder using unicast/anycast/broadcast mechanisms, with routing
      scalability handled through its namespace aggregation.  This model
      can introduce problems when the named entity is mobile, migrated,
      or replicated, as the names have to be announced in the routing
      control plane which can in turn introduce routing instability and
      scalability challenges (as the name aggregation to topological
      binding cannot be satisfied anymore).  Enabling ID/Locator split
      and managing this mapping in a separate name resolution service
      shall address the routing churn introduced by dynamic entities.
      CCN is unique in the sense that both name-based routing and
      resolution service can operate simultaneously driven by their use
      based on a given context.  For e.g. while inter-domain routing can
      be handled using a name resolution service, intra-domain routing
      can be based on name-based routing.

   o  ID and Locator namespaces are managed by different entities.  IDs
      are managed by applications, hence relevant only to consumers,
      producers and intermediate service points, while locator names are
      managed by a network administrator.  Locators map to network
      domains or specific network elements through which the named
      entity is reachable.  The relationship between the two is
      established during the namespace publishing phase, and managed by
      a separate name resolution service.  ID/Locator distinction in CCN
      allows applications to manage its own namespace and not be
      restricted by the naming rules imposed by the network.

   o  Affording ID/Locator split in an Interest message offers many
      advantages in CCN especially when a centralized control is applied
      such as using NFV/SDN frameworks, enabling efficiency and



Ravindran, et al.         Expires May 20, 2017                  [Page 3]


Internet-Draft       Forwarding-label support in CCN       November 2016


      flexibility in name resolution, routing, mobility, service
      chaining, and routing scalability.

   Considering the above requirements, we propose a Forwarding-label
   (FL) object, which acts as a locator and provides the flexibility to
   forward Interests on a name other than the one provided within the
   original Interest message with the ability to modify it within the
   network.  Handling ID/Locator mapping requires a control plane
   infrastructure and appropriate network layer state with security
   functions to prevent malicious usage.  Specific control plane or
   security mechanism of ID/Locator mapping is out of the scope of this
   document as many techniques can be used towards achieving this.  This
   draft presents various considerations towards FL object management
   such as: FL object insertion/modification/deletion, FL object
   processing by a CCN forwarder, PIT/CS implications for FL object
   carrying Interests, FL object Interest packet format, and security/
   trust considerations.  We then discuss the application of FL object
   in various scenarios.

2.  Forwarding-Label Object Proposal

   The use of FL is required when routing by ID is inefficient in
   scenarios such as replicated content, device mobility, or scalability
   challenges when ID based routing is employed.  FL objects are
   subjected to processing and modification in the network depending on
   the specific use case scenario.  Following we discuss various aspects
   of FL related to its semantics and management.

2.1.  FL Object Naming

   FL objects are container objects that include LID, service specific
   metadata, and security attributes for authentication.  LIDs are
   hierarchically structured topologically names where the names follow
   the definition in [1].  The security attributes are optional and may
   include validation payload and algorithm as discussed in [1].

2.2.  FL Object Insertion

   An FL object can be inserted in an Interest message by the consuming
   application or by the network.

   In certain situations, the application logic may use an FL object in
   addition to the ID in the Interest message or this action may also be
   triggered because of feedback from the network, for instance due to
   failure of routing the Interest message based on the ID.  In such
   situations, forwarders which process traffic from applications
   outside the trust domain require a way to validate the FL object.  A
   possible approach to ensure trust in such situations is discussed in



Ravindran, et al.         Expires May 20, 2017                  [Page 4]


Internet-Draft       Forwarding-label support in CCN       November 2016


   [8] where a trust binding is provided between the ID and the LID as a
   link object which can be validated by the forwarder.  To avoid the
   possibility of a misuse of an FL object, a default policy of the
   network may be to ignore it from untrusted applications and only
   choose to route by the content ID.

   In the case where the FL object is inserted by the network, FL object
   insertion is triggered at the ingress service routers of the network
   domain.  For instance, network may insert an FL object to an incoming
   Interest message, if the Interest message satisfies the flow service
   profiles that are imposed by the network administrator at the ingress
   edge routers.  The service profile matching actions may include
   matching an Interest name to a set of service prefixes or triggered
   by certain markings such as context-ID (for e.g. contexts may include
   service, trust, location) in the Interest message.  FL objects
   inserted within the trust domain may not require security validation.

   In situations where a forwarder handles both of these scenarios,
   policies can be applied at the ingress router to handle the two cases
   accordingly.  These policies may include the face on which the
   Interests arrives on, or the Interest IDs etc.

2.3.  FL Object Swapping

   An FL object can be swapped by another within the network in the
   context of a given service at designated points, such as the service
   edge routers, in the network.  As an FL object carries a LID, and
   with appropriate representation and security considerations in the
   Interest message, FL objects also can be potentially stacked if the
   Interest message has to be tunneled through a domain, where routing
   based on the top level FL object is not feasible.

2.4.  FL Object Termination

   FL objects are terminated by a forwarder when the LID in it matches
   its own LID.  Here we assume a forwarder to possibly have many LIDs
   such as domain-IDs or router-IDs.  For e.g. a forwarder (in a domain)
   identified as /att/santaclara can process an FL object with its LID
   set to this router's domain name or to a forwarder ID such as
   /att/santaclara/pop-x.  Whenever an FL object is terminated by the
   forwarder, depending on the service context, it can attach a new FL
   object, or conduct additional processing (e.g. re-resolution of the
   name to a new FL object) based on the Interest parameters.  The FL
   object can also include optional policy metadata based on which FL
   objects can be swapped in the network.






Ravindran, et al.         Expires May 20, 2017                  [Page 5]


Internet-Draft       Forwarding-label support in CCN       November 2016


3.  FL Object Message Format

   As FL objects are swappable in the network, it is proposed as a hop-
   by-hop field in the optional body of the fixed header as shown in
   Figure 1.  The optional FL container includes attribute of type FL-
   Object, which contains a name TLV identifying the LID (Figure 2).
   LID is a hierarchically structured variable length name as defined in
   [1].  A LID implies a locator such as an AS-ID, Gateway-ID, Router-ID
   or Host-ID.  In addition to the LID, optional FL metadata includes
   contextual information on the application or the service to aid the
   network for invoking an appropriate FL processing, such as trust
   validation of the FL object.  Optional security attributes, such as
   authentication information, can be included depending on the specific
   use case scenarios, such as secure name delegation information as
   discussed in [8], or signature of the consumer.


                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       |                   CCN Fixed Header                          |
                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       |              <Optional Hop-by-Hop TLVs>                     |
                       /                                                             /
                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       |         Type = FL-Object    |      Length                   |
                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       |                        LID TLV                              |
                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       /                      Optional FL Object Metadata            /
                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       /               Optional FL Object Security Attributes        /
                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       /                       Interest Message Body                 /
                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

            Figure 1: Interest message with hop-by-hop Optional Forwarding-Label TLV
















Ravindran, et al.         Expires May 20, 2017                  [Page 6]


Internet-Draft       Forwarding-label support in CCN       November 2016


                     +----------------------+------------------+-----------------+
                     | Forwarding-Label     |     Meaning      |      Value      |
                     +----------------------+------------------+-----------------+
                     | LID TLV              | Identifies an    |    Name TLV     |
                     |                      | AS-ID/Gateway-ID/|                 |
                     |                      | Host-ID          |                 |
                     +----------------------+------------------+-----------------+


                                  Figure 2: Locator-ID (LID) Definition


4.  FL Object Processing Rules

   The following discussion is based on the assumption that all
   forwarders must process the optional header fields.  In the context
   of CCN packet processing, FL object is only relevant when the
   decision to forward the Interest message is to be made.  At this
   stage, multiple options exist, assuming consistent policies exists
   throughout the domain: 1) In the first scenario, the rule may be that
   if an FL object is included in an Interest message, then it should be
   given preference over the ID.  This is under the assumption that FL
   objects are trusted indirections within the Interest message, and can
   be validated by the router if required; 2) In the second scenario,
   the forwarder could prioritize forwarding on the ID, and then forward
   on the LID at every hop; 3) In the third scenario, where policy based
   routing is involved, more complex routing approaches can be
   considered at the network edge, such as the forwarder could apply
   service policy on the Interest ID and choose to remove or swap it
   with a new FL object irrespective of the current FL object inserted
   in the Interest message, while the core nodes could use a more
   simpler approach, such as approach 1 or 2.  Following are the steps
   when approach 1 is applied.

   o  During Interest packet processing, while a forwarding decision is
      being made, if an LID is available then it should be preferred for
      forwarding over the name in the Interest message irrespective of
      the feasibility of ID based routing.

   o  The validation of FL depends on the trust context.  In trusted
      scenarios, where the applications and the network are managed by
      the same authority, the forwarder can bypass the validation.  In
      untrusted scenarios, the edge router may validate the FL that is
      inserted by the sender, and to avoid re-validations by successive
      forwarders, these Interests can be marked to have been validated
      at the ingress point.





Ravindran, et al.         Expires May 20, 2017                  [Page 7]


Internet-Draft       Forwarding-label support in CCN       November 2016


   o  If FL object is trusted and validated and the lookup based on LID
      in the FL object succeeds, then two possibilities exist: 1) for a
      non-terminating flow, the LID FIB lookup results in a next hop
      towards which the Interest is forwarded ; 2) for a terminating
      flow, LID lookup invokes a service logic wherein the service
      either re-resolves the Interest ID to another LID resulting in a
      new FL object or removes the current FL object and subjects the
      Interest to regular processing based on the ID in the Interest
      message.

   o  If the FL object is trusted and validated and the LID lookup
      fails, then the router can try to forward the Interest based on
      the Interest ID.  However if routing based on the Interest ID
      fails, then the router could raise an error condition and feedback
      the message to the previous hop, in the same or a different
      domain, with the appropriate error code.

5.  PIT Processing Implications

   To maintain the simplicity of the forwarding logic, the purpose of an
   FL object should be to guide the Interest towards the closest source
   of the resource entity, hence FL object may only be used for the
   forwarding decision and not be required for content object
   processing.  However there may be usage scenarios where the FL object
   state is required to be saved in the PIT and even piggybacked in the
   content object (CO).

   For example, in the case when there is no binding between the ID and
   the LID in the Interest expressed by a consumer, and multiple
   Interests arrive carrying the same ID but with different LIDs, then
   the expected outcome is to forward all such Interests with unique
   LIDs.  In this case the forwarder is required to save the LID along
   with the Interest ID in the PIT and forward the duplicate Interest
   whose LIDs differ from ID to LIDs state saved in the PIT.

   In another application, it may be required to decouple the choice of
   one consumer's LID from another consumer's LID, i.e, when a secure
   binding exists between the ID and the LID.  In this case, the
   forwarder stores the FL object in the PIT, and the returning CO
   should piggyback the Interest's FL object as long as the CO is from
   the location intended in the LID, which is matched against the
   pending PIT entry before continuing with the reverse path forwarding.
   In cases, where the FL object is swapped by the intermediate routers,
   the CO should be updated with the appropriate FL to ensure matching
   of the PIT entries along the previous hops.  These considerations are
   similar to those elaborated in [14].





Ravindran, et al.         Expires May 20, 2017                  [Page 8]


Internet-Draft       Forwarding-label support in CCN       November 2016


6.  Caching Implications

   The considerations here follow our previous discussion, where the FL
   object is piggybacked in the CO.  If there is an implicit security
   binding between the Interest ID and the LID, then the FL object state
   is piggybacked along with the CO, and the FL object in the incoming
   Interest should be matched against the CO's FL object before the
   cached content object is returned.

7.  Multiple Domain Scenario

   In wide area network scenarios, Interests cross multiple domains.  If
   an FL object is only trusted within the domain boundaries, then the
   FL object is removed before the Interest is forwarded to the next
   domain, which then, upon entry inserts a new forwarding label with
   the associated security attributes at the ingress of the next domain.
   But if trust exists between domains, such as one through a trusted
   third party (validated based on the FL object security binding), to
   use the FL inserted by the previous domain, then the intermediate
   domains can avoid further FL processing and use the FL object passed
   on by the previous domains.

8.  FL Object Security

   FL object security is related to the purpose it is used for and the
   control plane mechanism used to manage it.  Depending on the use case
   scenario of the FL, appropriate security mechanisms should be applied
   to secure the control and data planes to avoid exploitation of this
   feature.

   Generally, the major threats against the FL object approach is to
   manipulate the relationship between the name and the FL object.  Such
   manipulations can happen in various scenarios, some of which are
   listed as follows: (i) a malicious interceptor (acting as a
   publisher) intentionally injecting an incorrect mapping into the name
   resolution system; (ii) a malicious interceptor (between the edge
   router and the resolution server) manipulating the mapping sent back
   from the name resolution system when the edge router queries the
   mapping system ; (iii) a compromised intermediate router maliciously
   changing the FL object, e.g., with the wrong FL object or an out-
   dated FL object; (iv) an untrusted application injecting invalid FL
   object into the Interest message.

   To achieve network level FL security, appropriate mechanisms should
   be applied to provide mapping provenance, mapping integrity and to
   prevent replay attack to address these issues.  The security
   mechanisms applicable to the above discussed scenarios (i) and (ii)
   are similar to ones applied to secure other mapping systems such as



Ravindran, et al.         Expires May 20, 2017                  [Page 9]


Internet-Draft       Forwarding-label support in CCN       November 2016


   LISP [5] and DNS[7].  Scenario (iii) requires new security
   mechanisms, one such way is to enable a domain level trust
   infrastructure so that the mapping between the name and the FL object
   can be authenticated by the successive routers.

   In untrusted environments, when an FL object is inserted in the
   Interest message by the end hosts, appropriate authentication
   information should also be included in the FL object to allow ingress
   routers to optionally validate the delegation of the Interest ID to
   LID [8].  Furthermore, additional security policies can be enabled by
   the network to handle FL objects outside its trust domain.

9.  Use Case Scenarios

   Here we provide the discussions related to using FL objects in
   different scenarios.

9.1.  Handling Producer Mobility

   In the literature the different techniques to handle producer
   mobility can be classified into the following two types:

   o  Application-based approach, where the application takes the
      responsibility for announcing its reacheability to the network and
      triggering a network state change to enable Interest routing
      towards the mobile producer.  Most of the current proposals fall
      under this category, and these include the following two
      approaches: 1)The Kite proposal [13] implements an anchor based
      approach where consumers and producers agree on an anchor point
      based on external mechanisms and uses application initiated
      (traced and tracing) Interests to handle the producer mobility;
      2)The anchor-less proposal [15] is another application-based
      approach wherein enhanced name-based routing is used to track the
      mobile producer.  While these approaches allow consumers and
      producers to work on a single name space, it raises scalability
      concerns with increasing number of mobile nodes and number of
      applications signaling into the network.  As these approaches
      introduce more signaling in the network, the operational
      efficiency of packet forwarding is negatively affected due to the
      state changes that have to be applied to maintain the sanity of
      the Interest packet processing logic.  Another potential security
      issue with these approaches is that it can be prone to flooding
      attacks by malicious applications targeting specific application
      names and impeding their normal operation.

   o  Network-based approach uses the late-binding technique [11],
      wherein the reachability of the mobile node is handled by the
      network.  In this case applications can explicitly request



Ravindran, et al.         Expires May 20, 2017                 [Page 10]


Internet-Draft       Forwarding-label support in CCN       November 2016


      mobility for a given name space [9], with the network handling the
      mobility by tracking its latest location in the network through a
      name resolution system.  At the same time, through coordination of
      the old and new point-of-attachments (PoA) and in-band signaling
      one can achieve zero loss for a given Interest flow.  The late-
      binding technique uses ID/Locator split that is only applied at
      the PoAs, thereby avoiding any routing churn in the network due to
      producer mobility, while offering better scalability when the
      number of mobile producers increases.  Here the mobile entity (ME)
      registers a persistent name that requires mobility with its
      current point-of-attachment (PoA).  The PoA then registers the
      mapping between the name and the PoA's locator in its local name
      resolution system.  Then the domain updates the ME's home domain
      name resolution system with its current domain LID.  When a
      correspondent nodes expresses Interest for the name, it is first
      resolved to the current ME domain by the home domain.  When the
      Interest enters the domain offering mobility service, it is
      resolved again to the ME's current location.  Furthermore PoA-to-
      PoA signaling can be enabled to offer seamless forwarding of
      Interests whenever an ME changes its PoA.  In addition to
      correcting the path stretch the Interests re-routed from the old
      PoA can be marked and re-routed to the new PoA with the new FL.
      On the return path, the CO are also marked, this in-band marking
      is used by the ingress PoA at the consumer's end to re-resolve the
      mobile prefix to a new forwarding locater that would correct the
      path stretch.

9.2.  Manifests

   The FL objects can also be used to support the retrieval of nameless
   objects [10].  Using the current manifest proposal [6] a consumer
   receives a manifest with the ContentObjectHashIDs and their
   respective locator information.  A consuming application uses the
   locater as a routeable content name, while the ContentObjectHashID is
   used as a HashID restriction parameter.  Multiplexing the Interest
   name field as an ID and also as an LID has the following
   consequences: (1) a forwarder cannot distinguish between Interest
   packets containing ID or LID in the name field, as the protocol
   doesn't differentiate these two constructs; (2) it complicates
   Interest processing when LID is used as a name, by first requiring to
   check for the presence of ContentObjectHashID, and to use it to index
   the Interest based on it instead of the locator name; (3) more
   complications arise if an Interest packet arrives with two IDs i.e. a
   ContentObjectHashID as the hash restriction and the ID as the content
   name, in which case, one of them may seek precedence over the other.

   The above issues can be avoided through the use of the
   ContentObjectHashID as the content name and the locater in the FL



Ravindran, et al.         Expires May 20, 2017                 [Page 11]


Internet-Draft       Forwarding-label support in CCN       November 2016


   object.  In this case, a forwarder will always index the pending
   Interest table based on the content name.  The routing decision then
   would be based on the FL object depending on the routing policy in
   the forwarder.  This also avoids the situation of dealing with two
   IDs in the Interest packet, i.e. the application has to choose either
   ID or ContentObjectHashID as the content ID.  This use of FL object
   can be enforced in a straight forward manner by identifying flat-ID,
   e.g.  ContentObjectHashID, and routeable name as different typed name
   objects in the Interest packet.

   A possible high level forwarding logic for the edge/core router to
   support nameless objects based on the above discussion is presented
   in Figure 3.  Here edge router can also be a gateway node.






































Ravindran, et al.         Expires May 20, 2017                 [Page 12]


Internet-Draft       Forwarding-label support in CCN       November 2016


  Begin

  if Edge_Router
     If Interest arrives on a face with a flat-ID
        Then check for the presence of FL object
          If FL object is present, use the LID in the FL object for Interest forwarding

        If there no FL Object
          If policy allows, resolve the flat-ID with a NRS to obtain an FL object
            Use the FL object to route the Interest

     End

    If the Interest arrives with a routeable ID
      If there is FL object
        Then use the ID for forwarding and Remove the FL object

      If there is no FL object
        Match Interest ID with name policy for e.g. mobility or interest routing optimization
          If a name policy for resolution exists
            Then network resolution service is invoked on the ID  which returns an FL object
             Use the FL object to direct the Interest to the appropriate next hop
    End
  End

  if Core_Router
      if Interest arrives with an FL Object
        Use the LID for forwarding
      Else if Interest is with a Routeable ID
        Use the name for forwarding
  End

        Figure 3: Forwarding logic to support flat-ID and routeable ID at the edge router





   We discuss security implications of using ID and FL object in the
   Interest message depending on the ID type and

   o  Case 1 - ContentObjectHashId with FL object: This use case is a
      straight forward simplification of what is being proposed in [10].
      Here the locator is included within the FL object and the
      ContentObjectHashId is used as the name, so this shouldn't
      introduce any new security concerns.  This holds good for both
      application and network based FL object insertion.




Ravindran, et al.         Expires May 20, 2017                 [Page 13]


Internet-Draft       Forwarding-label support in CCN       November 2016


   o  Case 2 - Routeable ID with FL object: For UE based FL object
      insertion, this scenario can cause cache poisoning in the absence
      of signature check enforcement in the forwarders.  For the case
      when FL object is managed within a trusted domain, the security
      implications are discussed in Section 8.

9.3.  Interest Routing Optimization

   Networks which hosts its own or third party content/service can
   benefit from the ability to handle Interest routing logic in its
   domain opportunistically.  When a Interest seeking a specific content
   or service enters a network domain, the ingress router can redirect
   the Interest to the closest cache point or service location.

9.4.  Routing Scalability

   As discussed in [8], locator based routing can address routing
   scalability as the number of ASs are many orders less than the number
   of information objects.  This reduces the forwarding table in the DFZ
   zone in the order of number of ASs in the Internet.

10.  Informative References

   [1]        CCN Wire format, CCNX1., "http://www.ietf.org/id/
              draft-mosko-icnrg-ccnxmessages-00.txt.", 2013.

   [2]        Nikander, P., Gurtov, A., and T. Henderson, "Host identity
              protocol (HIP): Connectivity, mobility, multi-homing,
              security, and privacy over IPv4 and IPv6 networks", IEEE
              Communications Surveys and Tutorials, pp: 186-204, 2010.

   [3]        Atkinson, R., "An Overview of the Identifier-Locator
              Network Protocol (ILNP)", Technical Report, University
              College London, 2005.

   [4]        LISP, RFC6380., "https://tools.ietf.org/html/draft-ietf-
              lisp-sec-07.", 2014.

   [5]        LISP-Security, LISP-SEC., "https://tools.ietf.org/html/
              draft-ietf-lisp-sec-07.", 2014.

   [6]        CCNx, Manifest., "http://www.ccnx.org/pubs/
              draft-wood-icnrg-ccnxmanifests-00.html.", 2015.

   [7]        DNS-SEC, RFC4033., "DNS Security Introduction and
              Requirements.", 2005.





Ravindran, et al.         Expires May 20, 2017                 [Page 14]


Internet-Draft       Forwarding-label support in CCN       November 2016


   [8]        Afanasyev, A., "Map-and-Encap for Scaling NDN Routing.",
              NDN Technical Report ndn-004-02, 2015.

   [9]        Azgin, A., Ravidran, R., Chakraborti, A., and G. Wang,
              "Seamless Producer Mobility as a Service in Information
              Centric Networks.", 5G/ICN Workshop, ACM ICN Sigcomm 2016,
              2016.

   [10]       Mosko, M., "Nameless Objects.", IETF/ICNRG, Paris
              Interim 2016, 2016.

   [11]       Azgin, A., Ravindran, R., and G. Wang, "A Scalable
              Mobility-Centric Architecture for Named Data Networking.",
              ICCCN (Scene Workshop) , 2014.

   [12]       Cisco System Inc., CISCO., "Cisco visual networking index:
              Global mobile data traffic forecast update.", 2009-2014.

   [13]       Zhang, Y., Zhang, H., and L. Zhang, "Kite: A Mobility
              Support Scheme for NDN.", NDN, Technical Report NDN-0020 ,
              2014.

   [14]       CCNx Label Forwarding, CCNLF., "http://www.ccnx.org/pubs/
              ccnx-mosko-labelforwarding-01.txt.", 2013.

   [15]       Auge, J., Carofiglio, G., Grassi, G., Muscariello, L.,
              Pau, G., and X. Zeng, "Anchor-less Producer Mobility in
              ICN.", ICN, Sigcomm, 2015 , 2015.

   [16]       NSF FIA project, MobilityFirst.,
              "http://www.nets-fia.net/", 2010.

Authors' Addresses

   Ravishankar Ravindran
   Huawei Technologies
   2330 Central Expressway
   Santa Clara, CA  95050
   USA

   Email: ravi.ravindran@huawei.com










Ravindran, et al.         Expires May 20, 2017                 [Page 15]


Internet-Draft       Forwarding-label support in CCN       November 2016


   Asit Chakraborti
   Huawei Technologies
   2330 Central Expressway
   Santa Clara, CA  95050
   USA

   Email: asit.chakraborti@huawei.com


   Aytac Azgin
   Huawei Technologies
   2330 Central Expressway
   Santa Clara, CA  95050
   USA

   Email: aytac.azgin@huawei.com



































Ravindran, et al.         Expires May 20, 2017                 [Page 16]