Internet DRAFT - draft-wang-6man-ipv6-service-function-chain

draft-wang-6man-ipv6-service-function-chain






SFC WG                                                           C. Wang
Internet-Draft                                                   W. Meng
Intended status: Standards Track                         ZTE Corporation
Expires: July 9, 2016                                    January 6, 2016


                      IPv6 Service function Chain
             draft-wang-6man-ipv6-service-function-chain-01

Abstract

   Service function chain is the definition of an ordered set of service
   functions.  After instantiated, the service function path is created
   and the classified traffic is steered through the corresponding
   service function path and then forwarded to the final destination.
   This document tries to describe how to use IPv6 data plane and IPv6
   extension headers to realize service function chain in IPv6 network.

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
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   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on July 9, 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
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   (http://trustee.ietf.org/license-info) in effect on the date of
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as



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   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Convention and Terminology . . . . . . . . . . . . . . . . . .  4
   3.  An introduction on service function chain  . . . . . . . . . .  5
     3.1.  service function chain components  . . . . . . . . . . . .  5
     3.2.  data plane in service function chain . . . . . . . . . . .  5
   4.  An analysis on service function chain over IPv6 network  . . .  8
     4.1.  Routing header in IPv6 network . . . . . . . . . . . . . .  8
     4.2.  Destination options headers in IPv6 network  . . . . . . .  9
   5.  Service function path information header over IPv6 data
       plane  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
   6.  Metadata/Context headers over IPv6 data plane  . . . . . . . . 11
   7.  The procedures of IPv6 service function chain  . . . . . . . . 12
     7.1.  Example 1 (Identifier type= a list of addresses which
           identify SFFs and/or SFs)  . . . . . . . . . . . . . . . . 12
     7.2.  Example 2 (Identifier type = service function path
           identifier)  . . . . . . . . . . . . . . . . . . . . . . . 13
   8.  Service function chain simple offload over IPv6 network  . . . 15
   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 16
   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 17
   11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
     11.1. Normative References . . . . . . . . . . . . . . . . . . . 18
     11.2. Informative References . . . . . . . . . . . . . . . . . . 18
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19























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1.  Introduction

   Service function chain is the definition of an ordered set of service
   functions.  After instantiated, the service function path is created
   and the classified traffic is steered through the corresponding
   service function path and then forwarded to the final destination.

   This document tries to describe how to use IPv6 data plane and IPv6
   extension headers to realize service function chain in IPv6 network.
   Specifically, this document tries to provide:

   In section 3, an introduction on service function chain.

   In section 4, an analysis on service function chain over IPv6 network

   In section 5, service function path information header over IPv6 data
   plane

   In section 6, context headers over IPv6 data plane

   In section 7, the procedures of IPv6 service function chain

   In section 8, simple offload over IPv6 network

   In section 9, security for IPv6 service function chain


























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2.  Convention and Terminology

   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].

   The terms about SFC are all defined in [RFC7665].

   The terms about IPv6 are all defined in [RFC2460].










































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3.  An introduction on service function chain

3.1.  service function chain components

   Service function chain, defined in [RFC7665], defines several
   requisite components to implement SFC, including classifier, which
   performs classification for incoming packets, and Service Function
   Forwarder/SFF, which is responsible for forwarding traffic to one or
   more connected service functions according to the information carried
   in the SFC encapsulation, as well as handling traffic coming back
   from the SF and transporting traffic to another SFF and terminating
   the SFP.  And what's more, another significant component is Service
   Function/SF, which is responsible for specific treatment of received
   packets.

   Based on these SFC components, the service function paths are
   created.  Architecturally, within the same SFC-enabled domain, some
   SFPs may be fully specified, defining the exactly SFFs and SFs
   visited by classified packets, which are also named as Render Service
   Paths or RSPs.  While other SFPs may be relatively vague, some SFFs
   or SFs are not designated at the classifier, instead, SFFs can decide
   which attached SFs to visit when packets arrive.

3.2.  data plane in service function chain

   In SFC data plane, there also defines another important concept named
   SFC encapsulation.  The SFC encapsulation includes service function
   path information which determines how the packets are forwarded in
   the SFC domain, and metadata/context data information when such
   metadata is required.  In [I-D.ietf-sfc-nsh], the SFC encapsulation
   is defined as Network Service Header(NSH).

   In Figure 1, there is a Service Function Chain described as SFC1:
   Firewall(SF2) -- > DPI(SF4) -- > IPS(SF6).  After instantiated, SFC1
   is specified as a SFP:
   SFF1-->Firewall(SF2)-->SFF3-->DPI(SF4)-->SFF5-->IPS(SF6),which is
   identified by a SFPID.


                         +------+    +-------+    +-------+
                         |SF2/Fw|    |SF4/DPI|    |SF6/IPS|
                         +------+    +-------+    +-------+
                             |          |           |
         +-----------+    +----+      +----+      +----+        +------------+
         |Classifier |----|SFF1|------|SFF3|------|SFF5|--------| Destination|
         +-----------+    +----+      +----+      +----+        +------------+





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                           Figure 1: SFC Example

   In Figure 2, it illustrates the NSH format which is defined in
   [I-D.ietf-sfc-nsh].


        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |Ver|O|C|R|R|R|R|R|R|   Length  |    MD-type    | Next Protocol |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |          Service Path ID                      | Service Index |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Mandatory Context Header                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Mandatory Context Header                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Mandatory Context Header                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Mandatory Context Header                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       ~           Optional Variable Length Context Headers            ~
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 2: Network Service Header format

   When packets arrived at classifier, classification is triggered.
   Packets that satisfy classification rules are forwarded according to
   a specific SFP.  And also, there may be some metadata/context data
   resulted from the classification.  Then, the classifier encapsulates
   the SFP information and metadata information in the NSH, then
   encapsulates the NSH in the original packets, after that, chooses the
   appropriate overlay technology as transport layer to encapsulate the
   NSH packets, and forwards these encapsulated packets through overlay
   network to the next SFF.

   Packets arrive at an SFF from the overlay network.  The SFF
   determines the appropriate SF the packets should be forwarded to via
   SFP information carried in NSH.  After SF, the packets are returned
   to the SFF.  According to the SFP information, if the next hop is
   another SF associated with that SFF, packets then are forwarded to
   another SF.  If the next hop is not local SFs, packets then are
   encapsulated with appropriate overlay technology and forwarded to the
   next SFF along the path.  If there is no next hop and the last SF has
   been serviced, the SFF then removes the NSH and delivers the original
   packets to the network.




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   Sometimes, re-classification may occur on the SFF.  After re-
   classification, the service function path and/or the metadata
   information may change; new NSH then is encapsulated in the packets
   instead of original NSH.

   In some cases, there may be some SFC-unaware SFs attached to the SFF,
   and then the SFF acts as a SFC Proxy to remove the NSH and forward
   the packets to the SFC-unaware SF.  After receiving the served
   packets from the SFC-unaware SF, SFF then encapsulates the NSH again.

   Packets arrive at an SFC-aware SF from the attached SFF with NSH
   information.  The SF acquires the metadata if there is metadata
   information in the NSH, and then serves the packets.  If there is any
   requisite sharing metadata resulted from this SF, then this SF
   updates the metadata information in the NSH and then forwards the
   packets to the attached SFF.



































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4.  An analysis on service function chain over IPv6 network

   To achieve Service Function Chain, all the visited SFFs and SFs need
   recognize NSH.  Based on this new technology, there derives several
   new companion technologies to achieve integrated SFC, such as SFC
   Proxy, SFC OAM, SFC Loop Detection and avoidance, etc.

   In fact, in IPv6 network, there has an alternative method to realize
   service function chain, which may be easier to deploy service
   function chain function rapidly than SFC technology.

   In the following sections, how to rapidly realize service fucntion
   chain in IPv6 is proposed.  Specifically, the mechanism tries to
   encapsulate service function chain information in IPv6 extension
   headers of IPv6 packets, and then send the IPv6 packet along the path
   according to the service function chain informaiton.

4.1.  Routing header in IPv6 network

   Section 4.4 in [RFC2460] defines routing headers in IPv6 network.

   The routing header is used by an IPv6 source to list one or more
   intermediate nodes to be visited on the way to a packet's
   destination.  And the routing header is not examined or processed
   until it reaches the node identified in the Destination Address field
   of the IPv6 header.  The routing header is identified by a Next
   Header value of 43 in the immediately preceding header, and has the
   following format in Figure 3:


       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Next Header  |  Hdr Ext Len  |  Routing Type | Segments Left |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       .                                                               .
       .                       type-specific data                      .
       .                                                               .
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                 Figure 3: Routing header in IPv6 network

   Analyzing the mechanism of the routing header, it is a little similar
   to some features of service function chain.  For example, in IPv6
   network, the source node encapsulates routing header according to the
   packets' destination, and the information in the routing header is
   the forwarding path information.  Similarly, in SFC domain, the



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   classifier encapsulates NSH according to the packets' 3-tuple or
   5-tuple or other information in the packets, and the information in
   the NSH includes the forwarding path information.  Certainly, there
   are some differentiated feathers in SFC, such as re-classification,
   simple offload, bypass and so on.  There still has corresponding
   measures to work them out in IPv6 network.

4.2.  Destination options headers in IPv6 network

   Section 4.6 in [RFC2460] defines destination option headers in IPv6
   network.

   The destination option header is used to carry optional information
   that need be examined only by a packet's destination node(s), and has
   the following format in Figure 4:


       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Next Header  |  Hdr Ext Len  |                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
       |                                                               |
       .                                                               .
       .                            Options                            .
       .                                                               .
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


           Figure 4: Destination options headers in IPv6 network

   In SFC domain, metadata/context data is the context information
   shared between classifiers and SFs and among SFs, which means
   metadata only need be examined by classifiers and SFs.  As for
   classifier, it is the source of SFC packets.  As for SFs, they are
   intermediate destination nodes for SFC packets.

   Note that there are two possible ways to encode optional destination
   information in an IPv6 packet: either as an option in the Destination
   Option header, or as a separate extension header.












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5.  Service function path information header over IPv6 data plane

   To carry service function paths information in IPv6 network, this
   document tries to extend IPv6 routing header to carry them.  A new
   type of routing header is defined: the Service Function Chain routing
   type.  And it is illustrated as follow in Figure 5:


       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Next Header  |  Hdr Ext Len  |SFC RoutingType| Segments Left |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |Identifier Type|                Reserved                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       .                                                               .
       .             service function path information                 .
       .                                                               .
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


     Figure 5: service funciton path information header over IPv6 data
                                   plane

   Next Header: identifies the type of header immediately following the
   SFC routing header.

   Hdr Ext Len: identifies the length of the SFC routing header in
   8-octes units.

   SFC Routing Type: identifies the service function chain information
   is carried in the following data field, and need to be assigned by
   IANA.

   Segments Left: similar to service index in NSH.  Segments Left is
   decremented at each destination node and it is used as a service
   index to locate the next destination node along the service function
   path.

   Identifier Type: identifies how to describe the service function path
   information.  It may be a service function path identifier which
   identifies the service function path uniquely, or it may be a list of
   identifiers which identify the SFFs and/or SFs in the service
   function path, such as a list of addresses.

   Note that, except IPv6 routing header, carrying the service function
   paths information in a new IPv6 extension header can work out as
   well.





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6.  Metadata/Context headers over IPv6 data plane

   To carry metadata/context headers information in IPv6 network, this
   document tries to extend IPv6 destination option header to carry
   them.  A new option of destination option header is defined: Metadata
   Option.  And it is illustrated as follow in Figure 6:


         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
         |MD Option Type |  Opt Data Len |  Option Data
         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -


           Figure 6: metadata/context headers over IPv6 network

   Option data: identifies the metadata/context header information which
   needs to be shared between classifiers and SFs and among SFs.

   In order to distinguish different metadata type, here tries to define
   several metadata sub-options.  The format is as follow in Figure 7.
   For example, in Figure 8, there are network platform context
   information sub-option, network shared context information sub-
   option, service platform context information sub-option, service
   shared context information sub-option and some other optional
   variable length Context information sub-options.


        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - - - - - - - -
       |Net-Pla MD Type|  Sub-Opt Len  | Network Platform Metadata  ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - - - - - - - -
       |Net-Sha MD Type|  Sub-Opt Len  | Network Shared Metadata    ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - - - - - - - -
       |Ser-Pla MD Type|  Sub-Opt Len  | Service Platform Metadata  ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - - - - - - - -
       |Ser-Sha MD Type|  Sub-Opt Len  | Service Shared Metadata    ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - - - - - - - -
       ~                                                            ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - - - - - - - -


     Figure 7: sub-options for differentiated metadata/context headers

   Note that, except IPv6 destination option header, carrying the
   metadata/context headers in a new IPv6 extension header can work out
   as well.






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7.  The procedures of IPv6 service function chain

   This section tries to explain how to work out SFC in IPv6 network
   through IPv6 extension headers.

7.1.  Example 1 (Identifier type= a list of addresses which identify
      SFFs and/or SFs)

   Here consider the case of a source node S sending a packet to
   destination node D, after classification on the source node S, it
   turns out that the packet need to be served by SFC1: SF2 --> SF4.
   After instantiated, the exactly service function path is:
   SFF1-->SF2-->SFF3-->SF4.  Every SFFs and SFs are identified by an
   IPv6 address respectively.  So the packet is routed via intermediate
   nodes SFF1, SF2, SFF3, SF4 when traveling from the source node S to
   the destination node D. Here, tries to put SFF1/SF2/SFF3/SF4/D's IPv6
   addresses in a sequence list, and encapsulate this list of address in
   the extended IPv6 routing header defined in Section 5 in this
   document, which is illustrated in Figure 8.  What's more, the source
   node S may acquire some metadata/context headers information, which
   need to be encapsulated in the extended IPv6 routing header defined
   in Section 6 in this document.


       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Next Header  |  Hdr Ext Len  | Routing Type=5| Segments Letf |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Iden Type=2  |                Reserved                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                     Destination-IPv6                          ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                          SF4-IPv6                             ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                          SFF3-IPv6                            ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                          SF2-IPv6                             ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                          SFF1-IPv6                            ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


      Figure 8: a list of addresses to identify Service funciton path
                                information

   After that, mostly, the forwarding procedures are similar to the
   procedures defined in section 4.4 and section 4.6 in RFC2460.  Such
   as, SFFs and SFs as intermediate destination nodes need to process
   the metadata/context headers information in the destination option



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   headers, if needed, update the metadata/context headers information
   to be shared by the following nodes.  And also, SFFs and SFs as
   intermediate destination nodes need to analyze the service function
   path information and extract the next destination to update the IPv6
   destination address in IPv6 header.

   In some cases, the SFs' IPv6 address may be local IPv6 address, and
   then the SFFs need to recognize them and forward them correctly.

   In some other cases, the source node cannot get all the exactly SFFs/
   SFs' IPv6 addresses, then the intermediate nodes may need to update
   the IPv6 addresses list in the service function path information.

   Also, re-classification may be occurred in some intermediate nodes to
   re-steer the packets with updated list of addressed in service
   function path information and with updated metadata/context headers.

   What's more, sometimes, according to the IPv6 destination address,
   packets are forwarded to the next destination nodes may be through
   different transport layer protocols, such as native IPv6 transport
   layer protocol or MPLS transport layer protocol, or GRE transport
   layer protocol or other transport layer protocols.

7.2.  Example 2 (Identifier type = service function path identifier)

   Here still consider the case of a source node S sending a packet to
   destination node D, after classification on the source node S, it
   turns out that the packet need to be served by SFC1: SF2 --> SF4.
   After instantiated, the exactly service function path is:
   SFF1-->SF2-->SFF3-->SF4, which is correspond to a service function
   path identifier: SFPID1.  Here tries to encapsulate a SFPID to
   describe the whole service function path information in the IPv6
   extended header defined in section 5 in this document, which is
   relatively short and simple to carry and is illustrated in Figure 9.
   After acquiring the SFPID information, then acquire the corresponding
   metadata/context header, and encapsulate them in the extended IPv6
   routing header defined in Section 6 in this document.


       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Next Header  |  Hdr Ext Len  | Routing Type=5| Segments Left |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Iden Type=1  |                Reserved                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                             SFPID                             ~
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+





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                  Figure 9: Network Service Header format

   The source node S analyzes the SFPID and Segments Left in the routing
   header, and extracts the next SFF IPv6 address to update the IPv6
   destination address in IPv6 header, then forwards the packet to the
   destination through transport layer protocols, including native IPv6
   transport layer protocol or MPLS transport layer protocol, or GRE
   transport layer protocol or other transport layer protocols.

   When SFFs and/or SFs receive the packets, analyze the service
   function path information and metadata/context headers information,
   and take advantage of these information to determine the next
   destination node.  To help extract the next destination node, here
   may be need a service function path forwarding table corresponding to
   each SFPID to identifier where is the next station.

   Sometimes, re-classification may be occurred in some intermediate
   nodes to re-steer the packets with updated SFPID in service function
   path information and with updated metadata/context headers.
































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8.  Service function chain simple offload over IPv6 network

   TBD
















































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9.  Security Considerations

   TBD
















































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10.  IANA Considerations

   TBD
















































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11.  References

11.1.  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>.

   [RFC2460]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460,
              December 1998, <http://www.rfc-editor.org/info/rfc2460>.

   [RFC7665]  Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
              Chaining (SFC) Architecture", RFC 7665, DOI 10.17487/
              RFC7665, October 2015,
              <http://www.rfc-editor.org/info/rfc7665>.

11.2.  Informative References

   [I-D.ietf-sfc-nsh]
              Quinn, P. and U. Elzur, "Network Service Header",
              draft-ietf-sfc-nsh-01 (work in progress), July 2015.




























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Authors' Addresses

   Cui(Linda) Wang
   ZTE Corporation
   No.50 Software Avenue, Yuhuatai District
   Nanjing
   China

   Email: wang.cui1@zte.com.cn


   Wei Meng
   ZTE Corporation
   No.50 Software Avenue, Yuhuatai District
   Nanjing
   China

   Email: meng.wei2@zte.com.cn,vally.meng@gmail.com

































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