INTAREA                                                      S. Kanugovi
Internet-Draft                                              S. Vasudevan
Intended status: Standards Track                                   Nokia
Expires: January 18, 2017                                    F. Baboescu
                                                                Broadcom
                                                           July 17, 2016


                  Multiple Access Management Protocol
                draft-kanugovi-intarea-mams-protocol-00

Abstract

   A communication network includes an access network element that
   delivers data to/from the user and an associated core network element
   that typically is the IP gateway having connectivity with the
   application servers.  Multiconnectivity scenarios are common where a
   device can be simultaneously connected to multiple communication
   networks based on different technology implementations and network
   architectures like WiFi, LTE, DSL.  A smart combination and selection
   of access and core network paths can improve quality of experience
   that a user in a multiconnectivity scenario.  This document presents
   the problem statement and proposes solution principles.  It specifies
   the requirements and reference architecture for a multi access
   management services framework that can be used to flexibly select the
   best combination of uplink and downlink access and core network
   paths, ensuring better network efficiency and enhanced application
   performance.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 18, 2017.






Kanugovi, et al.        Expires January 18, 2017                [Page 1]


Internet-Draft                    MAMS                         July 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.  Conventions used in this document . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Solution Principles . . . . . . . . . . . . . . . . . . . . .   4
   5.  Requirements  . . . . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  Access technology agnostic interworking . . . . . . . . .   4
     5.2.  Support common transport deployments  . . . . . . . . . .   5
     5.3.  Independent Access path selection for Uplink and Downlink   5
     5.4.  IP anchor selection independent of uplink and downlink
           access  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     5.5.  Adaptive network path selection . . . . . . . . . . . . .   5
     5.6.  Multipath support and Aggregation of access link
           capacities  . . . . . . . . . . . . . . . . . . . . . . .   5
     5.7.  Scalable mechanism based on IP interworking . . . . . . .   5
     5.8.  Separate Control and Data plane functions . . . . . . . .   6
   6.  MAMS Reference Architecture . . . . . . . . . . . . . . . . .   6
   7.  MAMS call flow  . . . . . . . . . . . . . . . . . . . . . . .   8
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
     8.1.  Data and Control plane security . . . . . . . . . . . . .   9
   9.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .   9
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  10
     10.2.  Informative References . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].




Kanugovi, et al.        Expires January 18, 2017                [Page 2]


Internet-Draft                    MAMS                         July 2016


2.  Terminology

   "Client": The end-user device supporting connections with multiple
   access nodes, possibly over different access technologies.

   "Multiconnectivity Client": A client with multiple network
   connections.

   "Access network element": The functional element in the network that
   delivers user data packets to the client via a point-to-point access
   link like WiFi airlink, LTE airlink, DSL.

   "Core": The functional element that anchors the client's IP address
   used for communication with applications via the network.

   "User Plane Gateway": The functional element that can intercept and
   route user data packets.

   "Network Connection manager"(NCM): A functional entity in the network
   that oversees distribution of data packets over the multiple
   available access and core network paths.

   "Client Connection Manager" (CCM): A functional entity in the client
   that exchanges MAMS Signaling with the Network Connection Manager and
   configures the multiple network paths for transport of user data.

   "Anchor network element": The functional element in the network with
   connectivity via multiple access paths to the client.

   "Multi Access Data Proxy" (MADP ): This entity handles the user data
   traffic forwarding across multiple network paths.

3.  Problem Statement

   Typically, a device has access to multiple communication networks
   based on different technologies, say LTE, WiFi, DSL, MuLTEfire, for
   accessing application services.  Different technologies exhibit
   benefits and limitations in different scenarios.  For example, WiFi
   leverages the large spectrum available in unlicensed spectrum to
   deliver high capacities at low cost in uncongested scenarios with
   small user population, but can show significant degradation in
   application performance in congested scenarios with large user
   population.  Another example is LTE network, the capacity of which is
   often constrained by high cost and limited availability of the
   licensed spectrum, but offers predictable service even in multi-user
   scenarios due to controlled scheduling and licensed spectrum usage.





Kanugovi, et al.        Expires January 18, 2017                [Page 3]


Internet-Draft                    MAMS                         July 2016


   Additionally, the use of a particular access network path is often
   coupled with the use of the associated core network.  For example, in
   an enterprise that has deployed WiFi and LTE communications network,
   enterprise applications, like printers, Corporate Audio and Video
   conferencing, are accessible only via WiFi access connected to the
   enterprise hosted WiFi core, whereas the LTE access can be used to
   get LTE operator core anchored services including access to public
   internet.

   Application performance in different scenarios, therefore becomes
   dependent on the choice of the communication networks due to the
   tight coupling of the access and the core network paths.  Therefore
   to leverage the best possible application performance in the widest
   possible scenarios, a framework is needed that allows flexible
   selection of the combination of access and core network paths for
   application data delivery.

   For example, in uncongested scenarios, it would be beneficial to use
   WiFi access in the uplink and downlink for connecting to enterprise
   applications.  Whereas in congested scenarios, where use of WiFi in
   uplink by multiple users can lead to degraded capacity and increased
   delays due to contention, it would be beneficial to use scheduled LTE
   uplink access combined with WiFi downlink.

4.  Solution Principles

   This document proposes a Multiple Access Management Services(MAMS)
   framework for dynamic selection of uplink and downlink access and
   core network paths for a device connected to multiple communication
   networks.  The selection of paths is based on negotiation of
   capabilities and network link quality between the device and a
   functional element in the network, namely the network connection
   manager.  NCM has the intelligence to setup and offer the best
   network path based on device and network capabilities, application
   needs and knowledge of the network state.

5.  Requirements

   The requirements set out in this section are for the behavior of the
   MAMS mechanism and the related functional elements.

5.1.  Access technology agnostic interworking

   The access nodes can be of different technology types like LTE, WiFi
   etc.  Since MAMS routes user plane data packets at the IP layer,
   which makes it agnostic to the type of underlying technology used at
   the access node for delivery of data to the client.




Kanugovi, et al.        Expires January 18, 2017                [Page 4]


Internet-Draft                    MAMS                         July 2016


5.2.  Support common transport deployments

   The network path selection and user plane distribution should work
   transparently across transport deployments that include e2e IPsec,
   VPNs, and middleboxes like NATs and proxies.

5.3.  Independent Access path selection for Uplink and Downlink

   IP layer routing enables the client to transmit on uplink using one
   access and receive data on downlink using another access, allowing
   client and network connection manager to select the access paths for
   uplink and downlink independent of each other.

5.4.  IP anchor selection independent of uplink and downlink access

   A client is able to flexibly negotiate the IP anchor, core network,
   independent of the access paths used to reach the IP anchor depending
   on the application needs.

5.5.  Adaptive network path selection

   The network connection manager node has the ability to determine the
   quality of each of the network paths, e.g. access link delay and
   capacity.  The network path quality information is fed into the logic
   for selection of combination of network paths to be used for
   transporting user data.  The path selection algorithm can use network
   path quality information, in addition to other considerations like
   network policies, for optimizing network usage and enhancing QoE
   delivered to the user.

5.6.  Multipath support and Aggregation of access link capacities

   MAMS supports distribution and aggregation of user data across
   multiple network paths.  MAMS allows the client to leverage the
   combined capacity of the multiple network connections by enabling
   simultaneous transport of user data over multiple network paths.  If
   required, packet re-ordering is done at the receiver, client and/or
   the Anchor network element, when user data packets are received out
   of order.  MAMS allows flexibility to choose the flow steering and
   aggregation protocol based on capabilities supported by the client
   and the Anchor network element.

5.7.  Scalable mechanism based on IP interworking

   The mechanism is based on IP interworking, requiring only the IP
   connectivity between the access nodes and the interworking
   functionality is based on generically available IP routing and




Kanugovi, et al.        Expires January 18, 2017                [Page 5]


Internet-Draft                    MAMS                         July 2016


   encapsulation capabilities.  This makes solution easy to deploy and
   scale easily when different networks are added and removed.

5.8.  Separate Control and Data plane functions

   The client negotiates with a network connection manager the choice of
   access for both uplink and downlink accesses and the IP anchor(core).
   The network connection manager configures the actual user data
   distribution function residing in the Anchor element, thus
   maintaining a clear separation between the control and data plane
   functions.  This makes the MAMS framework amenable to SDN based
   architecture and implementations.

6.  MAMS Reference Architecture


                  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                  !     +-+-+-+-+-+-+-+-+       +-+-+-+-+-+-+-+-+     !
                  !     !               !       !               !     !
                  !     !Core(IP anchor)!       !Core(IP anchor)!     !
                  !     !(network 2)    !       !(network 1)    !     !
                  !     !               !       !               !     !
                  !     +-+-+-+-+-+-+-+-+       +-+-+-+-+-+-+-+-+     !
                  !          +-+-+-+-+-+-+-+-+-+-+-+-+                !
                  !          ! +-+-+-+  +-+-+-+      !                !
                  !          ! ! NCM !  !MADP !      !                !
                  !          ! +-+-+-+  +-+-+-+      !                !
                  !          +-+-+-+-+-+-+-+-+-+-+-+-+                !
                  !                                                   !
                  !     +-+-+-+-+-+-+            +-+-+-+-+-+-+-+-+    !
                  !     !           !            !               !    !
                  !     !           !            !               !    !
                  !     !access     !            !access         !    !
                  !     !(network 2)!            !(network 1)    !    !
                  !     !           !            !               !    !
                  !     +-+-+-+-+-+-+            +-+-+-+-+-+-+-+-+    !
                  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                                     +-+-+-+-+-+
                                     !  +-+-+-+!
                                     !  ! CCM !!
                                     !  +-+-+-+!
                                     !Client   !
                                     +-+-+-+-+-+

                   Figure 1: MAMS Reference Architecture




Kanugovi, et al.        Expires January 18, 2017                [Page 6]


Internet-Draft                    MAMS                         July 2016


   Figure 1 illustrates MAMS architecture for the scenario of a client
   served by 2 networks.  The NCM and MADP, functional elements, are
   introduced for supporting MAMS mechanisms.  The architecture is
   extendable to combine more than 2 networks, as well as any choice of
   participating network types (e.g.  LTE, WLAN, MuLTEfire, DSL) and
   deployment architectures (e.g. with user plane gateway function at
   the access edge).

   The MADP entity handles the user data traffic forwarding across
   multiple network paths.  MADP is the distribution node for uplink and
   downlink data with visibility of packets at the IP layer.
   Identification and distribution rules for different user data traffic
   type at the MADP are configured by the NCM.  The NCM configures the
   routing in the MADP based on signaling exchanged with the CCM in the
   client.  In the UL, NCM specifies the core network path to be used by
   MADP to route uplink user data.  In the DL, NCM specifies the access
   links to be used for delivery of data to the client.

   The distribution algorithm at the MADP is configured by the NCM,
   based on static and/or dynamic network policies like assigning access
   and core paths for specific user data traffic type, data volume based
   percentage distribution, and link availability and feedback
   information from exchange of MAMS signaling with the CCM at the
   Client.

   At the client, the Client Connection Manager (CCM) manages the
   multiple network connections.  CCM is responsible for exchange of
   MAMS signaling messages with the NCM for supporting functions like
   configuring UL and DL user network path configuration for
   transporting user data packets, link sounding and reporting to
   support adaptive network path selection by NCM.  In the downlink, for
   the user data received by the client, it configures IP layer
   forwarding for application data packet received over any of the
   accesses to reach the appropriate application module on the client.
   In the uplink, for the data transmitted by the client, it configures
   the routing table to determine the best access to be used for uplink
   data based on a combination of local policy and network policy
   delivered by the NCM.

   A user plane tunnel, e.g.  IPsec, may be needed for transporting user
   data packets between the MADP and the client.  The user plane tunnel
   is needed to ensure security and routability of the user plane
   packets between the MADP and the client.  The most common
   implementation of the user plane tunnel is the IPsec.  In deployments
   where the access node belonging to the two networks are connected via
   a secure and direct IP path, user plane tunnel may not be needed.





Kanugovi, et al.        Expires January 18, 2017                [Page 7]


Internet-Draft                    MAMS                         July 2016


7.  MAMS call flow



                            +----------------------------------------+
                            |   MAMS enabled Network of Networks     |
                            | +-----+    +-----+   +-----+    +-----+|
     +-----------------+    | |     |    |     |   |     |    |     ||
     |                 |    | |Netwo|    |Netwo|   |     |    |     ||
     |Client   +-----+ |    | |rk 1 |    |rk 2 |   |NCM  |    |MADP ||
     |         |CCM  | |    | |(LTE)|    |(WiFi)   |     |    |     ||
     |         +-----+ |    | +-----+    +-----+   +-----+    +-----+|
     +---+-------------+    +----------------------------------------+
         |        |              |          |         |          |
         |        |              |          |         |          |
         | 1.SETUP CONNECTION    |          |         |          |
         +<-------+------------->|          |         |          |
         |        |              |          |         |          |
         |        |  2. MAMS Capabilities Exchange    |          |
         |        |<-------------+----------+-------->|          |
         |        |              |          |         |          |
         |        |              |          |         |          |
         | 3. SETUP CONNECTION   |          |         |          |
         |<-------------------------------->|         |          |
         |        | 4a. NEGOTIATE NETWORK PATHS, FLOW |4b. Config|
         |        | PROTOCOL AND PARAMETERS           |MADP      |
         |        |<-------------+----------+-------->|<-------->|
         |        |              |          |         |          |
         |        |5. ESTABLISH USER PLANE PATH ACCORDING TO     |
         |        | SELECTED FLOW PROTOCOL            |          |
         |        |<-------------+----------+---------+--------->|
         |        |              |          |         |          |
         |        |              |          |         |          |

                         Figure 2: MAMS call flow

   Figure 2 illustrates the MAMS signaling mechanism for negotiation of
   network paths and flow protocols between the client and the network.
   In this example scenario, the client is connected to two networks
   (say LTE and WiFi).

   1.  UE connects to network 1 and gets an IP address assigned by
       network 1.
   2.  CCM communicates with NCM functional element via the network 1
       connection and exchanges capabilities and parameters for MAMS
       operation.  Note: The NCM credentials can be made known to the UE
       by pre-provisioning.




Kanugovi, et al.        Expires January 18, 2017                [Page 8]


Internet-Draft                    MAMS                         July 2016


   3.  Client sets up connection with network 2 and gets an IP address
       assigned by network 2.
   4.  CCM and MADP negotiate capabilites and parameters with NCM for
       establishment of network paths.

       4a.  CCM and NCM negotiate network paths, flow routing and
       aggregation protocols, and related parameters.

       4b.  NCM communicates with the MADP to exchange and configure
       flow aggregation and routing protocols, policies and parameters
       in alignment with those negotiation with the CCM.


   5.  CCM and MADP establish the user plane paths, e.g. using IKE
       [RFC7296] signaling, based on the negotiated flow protocol and
       parameters specified by NCM.

   CCM and NCM can further exchange messages containing access link
   measurements for link maintenance by the NCM.  NCM evaluates the link
   conditions in the UL and DL across LTE and WiFi, based on link
   measurements reported by CCM and/or link probing techniques and
   determines the UL and DL user data distribution policy.  NCM
   configures MADP and CCM with these policies for controlling network
   paths over which the user data is transported.  CCM may apply local
   policies, in addition to the network policy conveyed by the NCM.

8.  Security Considerations

   This section details the security considerations for the MAMS
   framework.

8.1.  Data and Control plane security

   Signaling messages and the user data in MAMS framework rely on the
   security of the underlying network transport paths.  When this cannot
   be assumed, network connection manager configures use of protocols,
   like IPsec [RFC4301] [RFC3948], for securing user data and MAMS
   signaling messages.

9.  Contributors

   This protocol is the outcome of work by many engineers, not just the
   authors of this document.  In alphabetical order, the contributors to
   the project are: Barbara Orlandi, Bongho Kim,David Lopez-Perez, Doru
   Calin, Jonathan Ling, Krishna Pramod A., Lohith Nayak, Michael
   Scharf.





Kanugovi, et al.        Expires January 18, 2017                [Page 9]


Internet-Draft                    MAMS                         July 2016


10.  References

10.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC4301]  Kent, S. and K. Seo, "Security Architecture for the
              Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
              December 2005, <http://www.rfc-editor.org/info/rfc4301>.

10.2.  Informative References

   [RFC3948]  Huttunen, A., Swander, B., Volpe, V., DiBurro, L., and M.
              Stenberg, "UDP Encapsulation of IPsec ESP Packets",
              RFC 3948, DOI 10.17487/RFC3948, January 2005,
              <http://www.rfc-editor.org/info/rfc3948>.

   [RFC7296]  Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
              Kivinen, "Internet Key Exchange Protocol Version 2
              (IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October
              2014, <http://www.rfc-editor.org/info/rfc7296>.

Authors' Addresses

   Satish Kanugovi
   Nokia

   Email: satish.k@nokia.com


   Subramanian Vasudevan
   Nokia

   Email: vasu.vasudevan@nokia.com


   Florin Baboescu
   Broadcom

   Email: florin.baboescu@broadcom.com








Kanugovi, et al.        Expires January 18, 2017               [Page 10]