Internet DRAFT - draft-fan-intarea-conet-ps-uc

draft-fan-intarea-conet-ps-uc







Internet Engineering Task Force                                   P. Fan
Internet-Draft                                                   H. Deng
Intended status: Informational                              China Mobile
Expires: September 20, 2014                               March 19, 2014


     CONET (Collaborative Network) Problem Statement and Use Cases
                    draft-fan-intarea-conet-ps-uc-00

Abstract

   This document describes problems of identifying and handling
   application traffic in an ISP' network, and use cases of
   collaborative network which enables active cooperation between ICPs
   and ISPs for better traffic operation.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Content based charging  . . . . . . . . . . . . . . . . .   4
     3.2.  QoS ability opening . . . . . . . . . . . . . . . . . . .   5
     3.3.  Application experience enhancement  . . . . . . . . . . .   6
   4.  Informative References  . . . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   Internet service providers (ISPs) around the world have been seeing
   booming growth of subscriber population and traffic volume of
   internet service over the years.  Data traffic congestion causes
   severe user experience degradation, which requires ISPs to better
   operate its data network.  Today's ISPs are making efforts to handle
   the traffic that goes through their networks more effectively.  [PCC]
   and [PCF] are some of the work that helps ISPs to solve the problems
   in data traffic operation.

   Meanwhile, internet content providers (ICPs) which provide the
   applications are gradually realizing the necessity of cooperation
   with the ISPs rather than having them be the dumb pipe.  By utilizing
   the ability of agile traffic management and classification provided
   by the network, ICPs intends to receive better treatment and
   differentiation on the traffic of their products, so as to meet user
   requirement and expectation, enhance user experience and viscosity,
   thus increase their revenue.

   Unlike the past time when they are performing independently without
   concern for each other, there is growing needs for ICPs and ISPs to
   build collaborative connections, which will benefit both of them as
   well as users.  There are also emerging operational models that
   reflect this connection.

   o  Content based charging offers customized, application specific
      billing strategy compared with traditional flat rate or time/
      volume based charging.

   o  Application based traffic optimization, such as QoS guarantee and
      firewalling, also requires the knowledge of the type of the
      traffic.

   One of the challenges ISPs meet in data traffic operation is to
   perceive the traffic in a finer granularity.  A traditionally widely
   used approach is to deploy content aware devices which are



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   specialized in identifying application information of the traffic
   flows using technics like DPI (Deep Packet Inspection) or DFI (Deep
   Flow Inspection).  Because of the tentative and deductive nature,
   these devices have met precision and timeliness limitation in
   practical deployment.  If an ICP can actively notify its
   characteristics to the network, traffic identification will be much
   more applicable and precise, and no dedicated identification devices
   are needed.

2.  Problem Statement

   Current common approach to identify traffic flows of applications in
   a network is to rely on dedicated content aware devices.  These
   devices not only parse fields on the IP and transport layers but also
   recognize application related information above transport layer.
   Content awareness ability mainly utilizes DPI function, which
   inspects characteristic signature (e.g. key string, binary sequence,
   etc.), and DFI function, which analyzes statistical characteristic
   and connection behavior of traffic flows, to identify application.
   However, there are limitations in deployment and operation of the
   ability.

   o  Since both DPI and DFI are essentially deductive methods difficult
      to fully grasp the characteristics of applications, accuracy of
      application identification cannot be guaranteed.  Error or
      omission is inevitable.

   o  Internet applications are apt to change frequently, so are the
      characteristics of themselves.  There will be a time latency to
      complete application traffic analysis and update signature
      database when a new application or version appears, which also
      contributes to the inaccuracy of identification.

   o  Content aware devices usually act as a black box.  There is no
      standard way in implementation or benchmarking.  So the ability
      highly depends on vendors.  Different boxes are likely to give
      different identification results to the same traffic.

   o  Content aware functions require parsing the payload of packets,
      leading to very high device resource consumption.  Built-in
      content aware function modules in network elements like GGSN/BRAS
      will affect the forwarding performance and thus impact data
      transmission.

   o  Investment cost cannot be neglected.  Sometimes the cost to
      identify the traffic is no less than that to forward the traffic.
      Operational cost of the additional identifying nodes is also an




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      important issue.  More potential failure points and possible
      optical power split will affect network quality.

   Another simpler approach is to identify traffic by IP addresses.  An
   example would be a white list of IP addresses of an application of
   the ICP, and network can match traffic with the list to pick the
   volume of the application.  This approach will have limitations when
   dealing with more complex scenarios.

   o  More granular traffic handling cannot be satisfied.  If part of
      the application traffic or traffic of some of the users is to be
      treated separately, IP based identification is too coarse.  For
      example, traffic for http://www.example.com/text/ and http://
      www.example.com/video/ is likely to receive different treatment
      but target to the same IP address; traffic from two users to the
      same server is a similar case.

   o  If cache/CDN is deployed in the network, then different users are
      likely to visit different addresses, and the addresses are likely
      to be different from the original addresses of ICPs.  Managing the
      list will have to consider the IP addresses of caches and CDN
      nodes deployed.

   o  Configuring the IP address list is not always extensible as the
      addresses may change, and sometimes it is not supposed to expose
      the addresses of ICPs.

3.  Use Cases

   If there is a way for an application to actively notify its
   information to the network, passive inspection devices will not be
   needed.  Bridging of application and network is also believed to be
   effective, precise and helpful in cooperation between ISPs and ICPs.
   Here we describe two use cases which benefit from active negotiation
   of application and network.

3.1.  Content based charging

   Commonly used billing method for mobile subscribers, e.g. volume
   based charging, does not distinguish from the angle of applications.
   It introduces difficulty for users to use applications consuming
   large volume in this billing model.  ICPs also have to strive for
   volume apart from preference and time of users.  Content based
   charging takes content related information into account and enables
   smarter pricing strategy.  Operators can place different prices for
   different types of traffic, and help ICPs build tight relationship
   with their users, e.g. wholesaling the data volume of an application




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   to its developer ICP so that users can use the application free of
   charge.

   An application intending to benefit from content based charging can
   notify its existence to the network and have its traffic charged in
   the desired way.  The following diagram shows an architecture of
   content based charging in 3GPP mobile network.

                            PCRF             CG/BOSS
                          +-----+           +-----+
                          |     |           |     |
                          +-----+----    ---+-----+
                             |       \  /
                             |        \/
                             |        /\
                             |       /  \
         +-----+          +-----+----    ---+-----+
         |     |----------|     |-----------|     |
         +-----+          +-----+           +-----+
           UE             GGSN/P-GW           ICP

   A typical process of content based charging for an application is as
   follows:

   1.  ICP applies for content based charging for its application to
       PCRF.  Information notified may include application identifier,
       description of flows needing special charging (e.g. signature, 5
       tuples), intended charging model (e.g. data volume of the
       application is free of charge), etc.

   2.  PCRF configures matching rules on GGSN/P-GW.

   3.  End user uses the application.

   4.  GGSN/P-GW receives and matches the traffic of the application,
       and provides charge records of the application to billing unit CG
       /BOSS.

3.2.  QoS ability opening

   QoS ability opening is provided by the network to enable dynamic
   access acceleration, priority guarantee and other service
   differentiation for ICPs, and new application based QoS selling
   business for operators.

   QoS opening can be realized in mobile networks as well as fixed
   broadband networks.  The following diagram depicts an architecture of
   open QoS ability in broadband access networks.  Current QoS in



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   broadband access networks is usually circuit or user based, achieved
   by configuring policies on network nodes like an edge router, and is
   not dynamic, on-demand or application specific.  If application
   characteristics are signaled to the network, network will be able to
   know the exact application information of the traffic, and thus
   perform QoS accordingly.  By signaling characteristics, application
   can decide when and how to request the network to provide QoS for its
   traffic.

                       Strategy Server
                           +-----+
                           |     |
                           +-----+
                              |
                              |
                              |
                              |
         +-----+           +-----+         +-----+
         |     |-----------|     |---------|     |
         +-----+           +-----+         +-----+
    User Application        BRAS       Application Server

   A typical process of the application initiated QoS can be described
   as follows:

   1.  End user application initiates data traffic.  The application may
       be a downloading service, online video service, etc.

   2.  Application decides that QoS is needed for its traffic, e.g. the
       user is logged as VIP.

   3.  Application signals information of the traffic needing QoS to the
       strategy server in the network.  Information signaled may include
       application identifier, flow description (e.g. 5 tuples),
       subscribed QoS contract, etc.

   4.  Strategy server validates the request from application and the
       contract with the ICP, and sends corresponding configuration to
       forwarding devices (e.g. BRAS) to perform requested QoS.

3.3.  Application experience enhancement

   There are many ICPs today providing internet based home products to
   users.  For example, an internet TV box uses WiFi to connect the
   internet and provides video programs to users.  ICPs wish to
   cooperate with ISPs providing the access service to improve the
   experience of their services, as access network is often congested
   due to extensive internet usage nowadays.  But currently classifying



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   the traffic of the services is rather complex when the traffic is
   mixed with other normal traffic in a single pipe (e.g. WiFi).
   Collaboration of ICP and ISP can solve the problem.

                      Authorization Server
                           +-----+
                           |     |
                           +-----+
                              |
                              |
                              |
                              |
         +-----+           +-----+              +-----+
         |     |    (((    |     |--------------|     |
         +-----+           +-----+              +-----+
       ICP Product         HGW/MiFi            ICP Server

   A typical process of this enhancement can be described as follows:

   1.  ICP product communicates with access gateway (e.g. HGW, MiFi) to
       request special treatment of its traffic.  Information signaled
       may include product identifier, authorization token, desired
       treatment (e.g. high priority, bandwidth reservation), etc.

   2.  Access gateway forwards the information to the authorization
       server, and authorization server signals back the result.

   3.  Access gateway coordinates with backhaul network to tag and
       classify the traffic of the product (can be specified by the
       address of the product).

4.  Informative References

   [PCC]      3GPP Technical Specification 23.203, , "Policy and
              charging control architecture", March 2012.

   [PCF]      BBF STRAW BALLOT WT-134, , "Broadband Policy Control
              Framework (PCF)", February 2012.

Authors' Addresses

   Peng Fan
   China Mobile
   32 Xuanwumen West Street, Xicheng District
   Beijing  100053
   P.R. China

   Email: fanpeng@chinamobile.com



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   Hui Deng
   China Mobile
   32 Xuanwumen West Street, Xicheng District
   Beijing  100053
   P.R. China

   Email: denghui@chinamobile.com












































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