One document matched: draft-nomad-mobileip-filters-04.txt

Differences from draft-nomad-mobileip-filters-03.txt



   Mobile IP Working Group                      N. A. Fikouras (editor) 
   INTERNET DRAFT                                            A. Udugama 
                                                               C. Goerg 
                                              ComNets-ikom, Uni. Bremen 
                                                               W.Zirwas 
                                                        J. M. Eichinger 
                                                             Siemens AG 
                                                              July 2003 
                                      
                                      
                Filters for Mobile IPv4 Bindings (NOMADv4) 
                    draft-nomad-mobileip-filters-04.txt 
    
    
   Status of this Memo 
    
   This document is an Internet-Draft and is in full conformance 
   with all provisions of Section 10 of RFC2026. 
    
    
   Internet-Drafts are working documents of the Internet Engineering 
   Task Force (IETF), its areas, and its working groups.  Note that      
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   Drafts. 
    
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   at any time.  It is inappropriate to use Internet-Drafts as 
   reference material or to cite them other than as "work in progress." 
    
   The list of current Internet-Drafts can be accessed at 
        http://www.ietf.org/ietf/1id-abstracts.txt 
   The list of Internet-Draft Shadow Directories can be accessed at 
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   Abstract 
    
   Filters for Mobile IPv4 bindings enables mobile nodes to associate 
   one or more Filters with mobility bindings during registration. 
   Flows that match a Filter will be processed as defined by the 
   Filter. In this manner, it is possible for a mobile node to 
   distribute flows or packets of a flow among its available points of 
   attachment, or to request that such flows are dropped before 
   reaching the mobile node. 
    
    
    
    
    
    
    
    
    
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Table of Contents 
 
   2 Terminology......................................................3 
   3 NOMADv4 Protocol Overview........................................5 
 3.1 Protocol Description............................................5 
 3.2 Model of Operation..............................................7 
   4 Backwards compatibility with RFC3344.............................9 
 5 Support for Multihoming...........................................9 
   6 Associating Filters with Mobility Bindings......................10 
 6.1 Mobile Node Considerations.....................................10 
  Filters for Mobile IPv4 Bindings Registration Flag................10 
  Creating a new mobility binding with Filters......................11 
  Replacing a Filter of a mobility binding by Index.................11 
  Adding new Filters to an existing mobility binding................11 
  Renewing a mobility binding with Filters..........................11 
  Deleting a Filter for a mobility binding..........................11 
  Deleting all Filters for a mobility binding.......................12 
  Transferring a Filter between mobility bindings...................12 
 6.2 Filtering Agent Considerations.................................12 
  Processing Filtering Requests.....................................12 
  Processing Filtering Replies......................................12 
  Applying Filters..................................................13 
 6.3 Home Agent Considerations......................................13 
  Filters for Mobile IPv4 Bindings Flag.............................14 
 Regional Registration Considerations...............................14 
  GFA/RFA Considerations............................................14 
   7 NOMADv4 Extensions to RFC3344 Registration Messages.............14 
 7.1 Behavior Aggregate Filters (BAF) Extension.....................16 
 7.2 Protocol Extension.............................................16 
 7.3 Source Address Extension.......................................17 
 7.4 Source Network Extension.......................................17 
 7.5 Source Port Extension..........................................18 
 7.6 Source Port Range Extension....................................18 
 7.7 Destination Port Extension.....................................19 
 7.8 Destination Port Range Extension...............................19 
 7.9 Free-Form Extension............................................20 
 7.10 Filter Control Extension......................................21 
 7.11 Filter Deletion Extension.....................................21 
 7.12 Filter Reply Extension........................................21 
  Code Values for Filter Reply Extension............................22 
   8 Intellectual Property Considerations............................22 
   8 Acknowledgements................................................23 
   References........................................................23 
   A. Changes from Previous Versions.................................23 
 A.1. Updates from version 02.......................................23 
 A.2. Updates from version 03.......................................24 
   Authors' Addresses................................................25 
     
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1 Introduction 
    
   This document extends the Mobile IPv4 [1] protocol by providing the 
   means for mobile nodes to notify Filtering Agents (Mobile IPv4 
   entities that can maintain simultaneous bindings with Filters) of an 
   association between Filters and specific mobility bindings. As such, 
   traffic intercepted by a Filtering Agent will be filtered and 
   individual flows will be handled as indicated by the control 
   information of the Filter. In the most typical scenario, individual 
   flows will be redirected to the (collocated) care-of address 
   indicated by the respective binding. This enables mobile nodes to 
   distribute active flows among their available points of attachment. 
   Alternatively, the mobile node may request when registering bindings 
   and filters that it does not wish to receive certain flows (it 
   wishes to have them dropped, with or without notification to 
   source). 
    
   Home Agents are unable to distinguish between individual flows and 
   therefore redirect all intercepted traffic for a mobile node to the 
   (collocated) care-of address indicated by its binding. Consequently, 
   as the binding is updated with every hand-off, the total of a mobile 
   node's active flows are redirected to the most recently registered 
   (collocated) care-of address. Furthermore, if a mobile node requests 
   for simultaneous bindings, it will receive at each registered 
   (collocated) care-of address a duplicate copy of every active flow. 
   However, a mobile node that maintains multiple points of attachment 
   may wish to associate certain flows with specific access interfaces. 
   As these access interfaces vary their (collocated) care-of address a 
   mobile node should be able to perform a Mobile IPv4 (IP-layer) hand-
   off for only a subset of its active flows. 
    
   Filters for bindings require that a mobile node includes in its 
   registration requests or binding updates a list of Filters. In this 
   manner, Filtering Agents (Home or Hierarchy Agents) become aware of 
   the relationship between certain flows and specific bindings. 
   However, the existence of those Filters does not affect in any way 
   the mobile node's choice on the point of attachment to be utilized 
   for the return path. 
    
    
2 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 RFC-2119 [2]. 
    
   This document uses the following terms: 
    
   Domain   A collection of networks sharing a common network  
            administration. 
    
   Home domain 
            As defined in [5]. 
    
     
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   Visited domain 
            The domain where the mobile node has one or more points of 
            attachment. 
    
   Home Agent (HA) 
            As defined in [1]. 
    
   Correspondent Node (CN) 
            As defined in [1]. 
    
   Gateway Foreign Agent (GFA) 
            As defined in [5]. 
    
   Regional Foreign Agent (RFA) 
            As defined in [5]. 
    
   Home Network 
            As defined in [1]. 
    
   Mobile Node (MN) 
            As defined in [1]. 
    
   Mobility Binding 
            As defined in [1]. 
    
   Filtering Agent (FLA) 
            Mobile IPv4 entities that can maintain Filters for mobility  
            bindings such as the HA, RFA, and GFA. 
    
   Filter Module (FLM) 
            The smallest module from which complex Filters are  
            defined. 
    
   Filter (FL) 
            A collection of Filter Modules and control information  
            describing how a flow(s) should be handled. 
    
   Filtering Request (FLRQ) 
            Mobile IPv4 signaling (registration request, binding  
            update) with the purpose of establishing a new mobility  
            binding that contains one or more Filters. 
    
   Filtering Reply (FLRP) 
            Mobile IPv4 signaling (registration reply, binding  
            acknowledgment) for returning the result of a Filtering  
            Request. 
    
   Default Filter (DF) 
            A special Filter applicable for all flows not matching any  
            other Filter. Is either defined by mobile node or  
            automatically allocated from Filtering Agents to the  
            lowest defined Index of zero. 
    
   Idle Mobility Binding (IMB) 
     
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            A mobility binding without Filters. 
    
    
3 NOMADv4 Protocol Overview 
    
   This section provides an overview of how Filters for Mobile IPv4 
   bindings can be realized. 
    
3.1 Protocol Description 
    
   Mobile nodes that wish to associate Filters with a (collocated) 
   care-of address are required to issue a registration request or 
   binding update with the æNÆ bit set, containing a list of Filters 
   that indicate which flows are associated with the registered 
   (collocated) care-of address. Such signaling is termed as Filtering 
   Requests. 
    
   A Filter is consisted of one or more Filter Modules and is 
   terminated by a Filter Control Extension. A Filter Module may 
   contain several predicates. There is an OR relationship between 
   predicates of a Filter Module. Moreover, there is an AND 
   relationship between Filter Modules of the same Filter. 
   Consequently, in order for a flow to match a Filter it is required 
   to qualify for all of the Filter Modules contained in the Filter. 
    
   Filter management is performed with the help of the Filter Control 
   Extension. It contains a FilterÆs Index and a Weight field. The 
   Index identifies uniquely a Filter for a given mobile node while the 
   Weight field indicates the relative amount of traffic for which a 
   Filter is applicable. If the Weight field is set to zero then all 
   matching flows will be dropped without notification to their source. 
   For any other value of Weight, matching flows will get forwarded to 
   the point of attachment indicated by the corresponding mobility 
   binding. In the case of overlapping Filters, packets of matching 
   flows will get distributed between multiple points of attachment 
   with respect to the Weight value of each Filter. 
    
   If a mobile node needs to delete a Filter, then it is required to 
   add a Filter Deletion Extension at the end of all Filter 
   declarations. The Filter Deletion Extension contains a list of 
   Filter indexes that the mobile node wants to have deleted. 
    
   A mobile node may define more than one Filters for a specific 
   mobility binding. The declaration of these Filters may take place 
   during one or more Filtering Requests. 
    
   Filtering Requests will be processed by one or more Filtering 
   Agents. A Filtering Agent can be any Mobile IPv4 entity that can 
   maintain mobility bindings with Filters, like a HA, RFA or GFA. 
    
   Flows that fail to match any of the defined Filters are handled as 
   defined by the Filter with the lowest possible Index of zero, termed 
   as Default Filter. A mobile node may define some of the attributes 
   of the Default Filter such as the associated mobility binding and 
     
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   its Weight field by issuing a Filtering Request. Otherwise, these 
   will be configured by each Filtering Agent. In that case, the 
   Default Filter is associated with the mobility binding with the 
   longest outstanding lifetime and the Weight will be set to the value 
   of 1. However, different Filtering Agents may use different 
   algorithms to determine the Default Filter. 
    
   A mobile node may issue Filters corresponding to flows that do not 
   yet exist. When such a flow is initiated it will be handled by the 
   Filtering Agents as indicated by the respective Filter. 
    
   A Filtering Agent that receives a Filtering Request is required to 
   establish a mobility binding and set up a tunnel as per [1]. Newly 
   declared Filters should be associated with the registered mobility 
   binding. 
    
   Binding management is performed with the help of the æSÆ bit as 
   described in [1]. RFAs and GFAs receiving Filtering Requests 
   containing new Filter definitions or Solo Filter Control Extensions 
   are required to handle them as Home Registrations [5] and forward 
   them all the way to the HA. In this manner it is assured that 
   Filtering Agents throughout the registration path maintain a 
   consistent set of Filters for a mobile node. In the case that an RFA 
   or GFA receives a Filtering Request with the purpose of transferring 
   one or more known Filters between two mobility bindings within its 
   hierarchy then it is required to handle it locally and issue a 
   Filtering Reply. 
    
   A Filtering Reply is a registration reply with the æNÆ bit set. 
   Filtering Replies are used in order to relay the results of a 
   Filtering Request. As such, a Filtering Reply contains a Filter 
   Reply Extension for each of the Filters contained in the 
   corresponding Filtering Request indicating the Index of a Filter 
   along with a Code signifying the result. The Code is used to relay 
   success or the reason of rejection to the mobile node. 
    
   Successive updates to the Filters of a mobility binding may lead to 
   a mobility binding without any Filters. Such bindings remain idle 
   until either allocated a Filter, expire or deregistered by the 
   mobile node. A mobility binding in that state is termed as an Idle 
   Mobility Binding. When a Filtering Agent maintains exclusively Idle 
   Mobility Bindings for a mobile node then it is required to act as 
   per [1] and to ignore the behavior presented in this document. 
    
   A Filter remains valid for the lifetime of the corresponding 
   mobility binding. If the lifetime of a binding expires or it is 
   cancelled by the registration of another mobility binding then all 
   associated Filters are deleted from record. When renewing a mobility 
   binding a mobile node is not required to include any reference to 
   any Filters. If a mobile node wishes to reuse a deleted Filter then 
   it will have to reissue a Filtering Request. 
    
   The rules by which a mobile node decides on the set of Filters are 
   considered beyond the scope of this document. The extensions 
     
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   presented in this document do not affect in any way the mobile 
   nodeÆs choice on the point of attachment to be used when returning 
   traffic. 
    
3.2 Model of Operation 
    
   Filters for Mobile IPv4 Bindings has two modes of operation that can 
   be seamlessly combined but for the sake of simplicity are covered in 
   this section separately. The first model of operation concerns the 
   management of whole flows while the second model addresses the 
   problem of load balancing the individual packets of flows between 
   points of attachment. 
    
   Figure 1 illustrates the first model of operation. It shows a mobile 
   node with two home addresses each originating from a different home 
   network (multihoming). The mobile node maintains multiple points of 
   attachment in several visited domains. A visited domain may consist 
   of several different IP administrative domains (subnetworks). The 
   extensions presented do not provide any restriction as to how many 
   points of attachment a mobile node may maintain within a visited 
   domain as long as each point of attachment belongs to a different 
   subnetwork. When a mobile node acquires point of attachment in the 
   home network then it is required to give up all other points of 
   attachment. 
    
   In figure 1, the mobile node has two separate points of attachment 
   in the Mobile IPv4 hierarchy of visited domain A. In addition, the 
   mobile node maintains two more points of attachment through visited 
   domains B and C. The mobile node maintains five incoming flows from 
   correspondent nodes CN1, CN2 and CN3. Flows associated with CN1 are 
   denoted with 'a' and 'b' while the respective flows for CN2 are 
   denoted with 'c' and 'd'. The flow associated with CN3 is denoted 
   with 'e'. 
    
   Communications originating CN1 are addressed at the mobile nodeÆs 
   home address from home network 1. For that home address the mobile 
   node maintains two simultaneous mobility bindings at the GFA each 
   associated with a Filter indicating that flows 'a' and 'b' should be 
   delivered to different points of attachment. The Filtering Requests 
   that established these mobility bindings and defined the 
   corresponding Filters where treated by the GRA as Home Registrations 
   and where forwarded to the HA1. As such, the GFA as well as the HA1 
   maintain a list of Filters for the mobile node. The difference is 
   that the GFA maintains two separate simultaneous mobility bindings 
   with Filters for two different registered (collocated) care-of 
   addresses while HA1 maintains a single mobility binding with two 
   Filters, indicating the GFA as the care-of address. In this manner, 
   Filter information is kept in all Filtering Agents in the 
   registration path but filtering occurs at the most appropriate 
   Filtering Agent. That is, flows denoted with 'a' and 'b' are 
   distributed between the available points of attachment at the GFA, 
   as this is the last common Filtering Agent on their path to the 
   mobile node. 
    
     
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   Flows denoted with 'c', 'd' and 'e' are addressed at the mobile 
   nodeÆs home address from home network 2. These are filtered at HA2 
   and tunneled to different visited domains. The mobile node has 
   indicated in its Filters that it does not wish to receive flow 'e'. 
   As such, flow 'e' is terminated at the HA2 as this the first 
   Filtering Agent encountered in the path to the mobile node and there 
   is no need for that traffic to propagate further into the network. 
   The rejection of a flow will take place either without any 
   notification to its source. 
    
   To return traffic a mobile node may choose any of the available 
   points of attachment. 
    
              +---------------------+   +-------------+     +-------+   
              |  Visited Domain  A  |   |             |     |  CN1  |   
              |                     |   |             |     +-------+   
              |                     |   |             |         a|      
     a a a a a a +------+ a a a     |   |             |         b|      
      -----------|  FA  |-----      |   |             |   +-----a|----+ 
    a|        |  +------+     |a        |             |   |     b|    | 
     |        |           +-------+     |             |   |  +------+ | 
    a|        |           |  GFA  |--------------------------| HA1  | | 
     |        |           +-------+ babababababababababababab+------+ | 
    a|        |  +------+     |b    |   |             |   |           | 
     |   --------|  FA  |-----      |   |             |   |   Home    | 
    a|  |b b b b +------+b b b b    |   |             |   | Network 1 | 
     |  |     |                     |   |             |   +-----------+ 
    a|  |b    +---------------------+   |   Public    |                 
   +------+                             |   Network   |   +-----------+ 
   |  MN  |   +---------------------+   |             |   |   Home    | 
   +------+   |  Visited Domain  B  |   |             |   | Network 2 | 
     |d |c    |                     |   |             |   |           | 
     |  |  c c c +------+ c c c c c c c c c c c c c c c c c c c c c   | 
     |d  --------|  FA  |-----------------------------------------    | 
     |        |  +------+           |   |    d d d d d d d d d d  |c  | 
     |d       |                     |   |  d ------------------   |   | 
     |        |                     |   |   |         |   |    |d |c  | 
     |d       |                     |   |  d|   dcdcdcdcdcdc +------+ | 
     |        +---------------------+   |   |  c ------------| HA2  | | 
     |d                                 |  d|  d|     |   |  +------+ | 
     |        +---------------------+   +-- |--c|-----+   |     e|    | 
     |d       |                     |      d|  d|         +------|----+ 
     | d d d d d d d d d d d d d d d d d d  |  c|               e|      
      --------------------------------------   d|                |      
              |                     |          c|               e|      
              |  Visited Domain C   |       +-------+       +-------+   
              |                     |       |  CN2  |       |  CN3  |   
              +---------------------+       +-------+       +-------+   
    
   Figure 1: A mobile node with multiple points of attachment in 
             different visited domains. Incoming flows are redirected  
             by the respective Filtering Agents to a different  
             (collocated) care-of address. In addition, mobile node  
             chooses to have its HA2 block flow 'e' . Blocking a flow  
     
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             occurs without notification to the sender. 
    
   Figure 2, illustrates the second model of operation. It shows a 
   mobile node that maintains two points of attachment in visited 
   domains A and B. In addition, the mobile node maintains one active 
   flow from CN1, denoted with 'a'. It can be seen that this flow gets 
   distributed at the HA and variable amounts of the flow are delivered 
   to a different point of attachment. 
    
                                        +-------------+     +-------+   
                                        |   Public    |     |  CN1  |   
                                        |   Network   |     +-------+   
              +---------------------+   |             |          |a     
              |  Visited Domain  A  |   |             |          |      
              |                     |   |             |   +------|a---+ 
      a  a  a |a  a  a  a  a  a  a  a  a| a  a  a  a  a  a| a    |    | 
       ------------------------------------------------------- a |a   | 
     a|       |                     |   |             |   |   |  |    | 
      |       +---------------------+   |             |   |   |a |a   | 
   +------+                             |             |   |  +------+ | 
   |  MN  |   +---------------------+   |             |   |  |  HA  | | 
   +------+   |                     |   |             |   |  +------+ | 
     |a       | a         a         a   |     a       | a |   |       | 
      --------------------------------------------------------        | 
              |                     |   |             |   |    Home   | 
              |  Visited Domain  B  |   |             |   |  Network  | 
              +---------------------+   +-------------+   +-----------+ 
    
   Figure 2: A mobile node with multiple points of attachment in 
             different visited domains. A single incoming flow is  
             distributed by the respective Filtering Agents to a   
             different (collocated) care-of address. 
    
    
4 Backwards compatibility with RFC3344 
    
   A domain that supports Filters for Mobile IPv4 Bindings should also 
   be backwards compatible. In Mobile IPv4, mobile nodes issue 
   registration requests without any Filters and without the æNÆ bit 
   set. Any such registration request would cause a Filtering Agent to 
   act as per [1] and to provide normal Mobile IPv4 services. In 
   addition, it is stated that a Filtering Agent maintaining only Idle 
   Mobility Bindings for a mobile is required to act as per [1] and to 
   ignore the behavior presented in this document. 
  
  
5 Support for Multihoming 
    
   The extension presented in this document are compatible with the 
   multihoming support of Mobile IPv4. In multihoming support a mobile 
   node may use different home addresses in order to distribute 
   incoming flows from different CNs. Filters for Mobile IPv4 Bindings 
   builds on top of that to enable mobile nodes to distribute flows 
     
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   addressed to the same home address from same or different CNs, for 
   one or more home addresses. 
    
    
6 Associating Filters with Mobility Bindings 
    
   This section gives a detailed description of the steps taken by a 
   mobile node that wishes to associate Filters with its mobility 
   bindings. Furthermore, it is presented how a Filtering Agent reacts 
   to the receipt of a Filtering Request. 
    
6.1 Mobile Node Considerations 
    
   A mobile node that acquires a (collocated) care-of address within a 
   visited domain may issue a Filtering Request with the æNÆ bit set, 
   containing a list of Filters. All included Filters will be 
   associated with the registered (collocated) care-of address at all 
   Filtering Agents encountered on the path to the HA. A mobile node 
   that maintains multiple points of attachment may request for 
   simultaneous mobility bindings by setting the æSÆ bit in its 
   Filtering Requests. 
    
 Filters for Mobile IPv4 Bindings Registration Flag 
    
   The only change to the Registration Request defined in [1] is a flag 
   indicating that the mobile node wishes to receive Filters for Mobile 
   IPv4 Bindings services. The flag is inserted after the flags defined 
   in [5]. 
    
       0                   1                   2                   3 
       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 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |     Type      |S|B|D|M|G|r|T|N|          Lifetime             | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                          Home Address                         | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                           Home Agent                          | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                        Care-of Address                        | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |                                                               | 
      +                         Identification                        + 
      |                                                               | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      | Extensions ... 
      +-+-+-+-+-+-+-+- 
    
   The flag is defined as follows: 
    
        N   NOMADv4 Extension. The mobile node wishes to receive  
            Filters for Mobile IPv4 Bindings, services 
    
     
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   Filter declarations and Filter Deletion Extensions are included in a 
   Registration Request after any security extensions. In addition, a 
   Filter Deletion Extension may follow any Filter declarations. 
    
   A Filtering Reply is a Registration Reply with the æNÆ bit set 
   containing a Filter Reply Extension for each Filter contained in the 
   respective Filtering Request indicating the Index of the Filter that 
   it refers to along with its result Code. 
    
   For the management of Filters seven scenarios are identified. These 
   are presented along with the actions to be undertaken by the mobile 
   node. 
    
 Creating a new mobility binding with Filters 
    
   In order to create a new mobility binding with associated Filters 
   the mobile node must issue a Filtering Request including one or more 
   full Filter definitions (one or more Filter modules with a Filter 
   Control Extension). Each of the Filters must be allocated a 
   different Index number. 
    
   The destination of the Filtering Request is identified as described 
   in [1] or [5]. If the mobile node already maintains a mobility 
   binding that it wishes to keep then it should set the æSÆ bit in the 
   Filtering Request. 
    
 Replacing a Filter of a mobility binding by Index 
    
   In order for a mobile node to replace an existing Filter it is 
   required to issue a Filtering Request with a full definition of the 
   new Filter. The Filter Control Extension of the Filter must indicate 
   the Index of the Filter to be replaced. 
    
 Adding new Filters to an existing mobility binding 
    
   In order for a mobile node to add new Filters to an existing 
   mobility binding it is required to act as if creating a new mobility 
   binding with Filters. It is necessary for the new Filter to adopt an 
   unallocated Index number otherwise it would be replacing the 
   existing Filter with that Index. 
    
 Renewing a mobility binding with Filters 
    
   Periodically, a mobile node is required to renew its mobility 
   bindings in order to extend their lifetime. Renewing a mobility 
   binding may occur as described in [1] or [5]. Registration Requests 
   with the purpose of renewing Filters and mobility binding are 
   required to set the æNÆ bit but not include any reference to the 
   Filters associated with the mobility binding. 
    
 Deleting a Filter for a mobility binding 
    
   In order for a mobile node to delete an existing Filter for a 
   mobility binding, it is required to issue a Filtering Request from 
     
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   any (collocated) care-of address. The Filtering Request must include 
   a Filter Deletion Extensions indicating the Index of each Filter to 
   be deleted. 
    
 Deleting all Filters for a mobility binding 
    
   In order for a mobile node to delete all existing Filter for a 
   mobility binding, it is required to issue a Filtering Request from 
   any (collocated) care-of address. The Filtering Request must include 
   a Filter Deletion Extensions with the Index field set to zero. 
    
 Transferring a Filter between mobility bindings 
    
   In order for a mobile node to transfer an existing Filter between 
   two mobility bindings it is required to act as if creating a new 
   mobility binding with Filters and send out a Filtering Request from 
   the point of attachment to which it wants to have the Filter 
   transferred. The Filtering Request must contain the full Filter 
   definition. RFAs and GFAs receiving Filtering Requests with the aim 
   of transferring known Filters between mobility bindings must issue a 
   Filtering Reply and avoid forwarding to the HA. 
    
6.2 Filtering Agent Considerations 
    
   This section contains general considerations for Filtering Agents. 
   These are Mobile IPv4 entities that can maintain mobility bindings 
   such as HAs GFAs and RFAs. 
    
 Processing Filtering Requests 
    
   Filtering Agents that receive a Filtering Request containing one or 
   more previously unknown Filter declarations or a Filter Deletion 
   Extension are required to cache them and forward the Filtering 
   Request to the next Filtering Agent until it reaches the HA. In this 
   manner it is ensured that all Filtering Agents in the registration 
   path maintain the same record of Filters for a mobile node. The 
   address of the next Filtering Agent is determined with the 
   mechanisms described in [5]. 
    
   Filtering Requests that do not contain any Filter declarations or a 
   Filter Deletion Extensions are intended for refreshing the lifetime 
   of a mobility binding and its Filters and need to be forwarded to 
   the next Filtering Agent until they reach the HA. If the mobile node 
   does not maintain any Filters for this mobility binding then the 
   Filtering Agent must issue a Filtering Reply including a Filter 
   Reply Extension with the Index set to zero and the Code field set to 
   the NO FILTERS error code indicating that the mobile node does 
   maintain any Filters. 
    
 Processing Filtering Replies 
    
   Upon receiving a Filtering Reply, a Filtering Agent needs to look 
   into the attached Filter Reply Extensions in order to determine the 
   outcome of the Filtering Request. That is, if the Filtering Agent 
     
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   encounters a Filter Reply Extension with the Code field set to the 
   error code UNKNOWN FILTER (section 7.12) then it is required to 
   flush all Filters of all mobility bindings for the mobile node and 
   immediately forward the Filtering Reply to the next Filtering Agent. 
   For every Filter Reply Extension with a successful code, the 
   Filtering Agent is required to apply the corresponding Filter. For 
   Filter Reply Extensions with error codes, the Filtering Agent is 
   required to take no action. Once all Filter Reply Extensions have 
   been processed, a Filtering Agent may proceed with the processing of 
   Filter Deletion Extensions and the deletion of all Filters whose 
   Indexes are enlisted in the extension. . If the Index field is set 
   to zero then all Filters of the corresponding mobility binding must 
   be deleted. If the Index does not correspond to any defined Filter 
   then no Filter is deleted. Finally, a Filtering Agent must forward 
   the Filtering Reply to the next Filtering Agent until it reaches the 
   mobile node. 
   no Filter is deleted. 
    
 Applying Filters 
    
   When a Filtering Agent intercepts a packet for a mobile node for 
   which it maintains a mobility binding it is required to identify 
   whether the packet matches any of the Filters associated with the 
   mobility binding. If so, then the packet is forwarded to the 
   respective point of attachment with respect to the Weight value of 
   the Filter. If the Weight value is zero then the flow gets dropped 
   without any notification to its source. If no matching Filter is 
   found then the packet is handled as indicated by the Default Filter. 
   If a flow matches more then one Filter then its packets are 
   distributed between the multiple points of attachment with respect 
   to the Weight value of each Filter. 
    
   When a mobility binding expires or is deregistered by a mobile node 
   then all associated Filters are deleted. Mobility bindings that have 
   been stripped of their Filters are considered to be Idle Mobility 
   Bindings. This means that they remain unused until either allocated 
   a Filter or expire. 
    
6.3 Home Agent Considerations 
    
   When a HA receives a Filtering Request that contains one or more 
   Filter declarations then these Filters must be associated with the 
   registered (collocated) care-of address.  
   Following that, all Solo Filter Control Extensions must be 
   processed. Then the HA is required to issue a Filtering Reply 
   including a Filter Reply Extension for each Filter in the Filtering 
   Request indicating the Index of the Filter and its result Code. 
    
   When a HA receives a Filtering Request without any Filter 
   declarations and Filter Deletion Extensions then it is required to 
   renew the lifetime of the corresponding mobility binding along with 
   its Filters and to issue a Filtering Reply. If the mobility binding 
   has no associated Filters then the HA must issue a Filtering Reply 
   including a Filter Reply Extension with the Index set to zero and 
     
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   the Code field set to the NO FILTERS error code indicating that the 
   mobile node does maintain any Filters. 
    
   For each Filter in a Filtering Request, a Filtering Agent must 
   include a Filter Reply Extension indicating its Index and its result 
   Code. If authentication of the Filtering Request fails then none of 
   the Filters must be applied. 
    
 Filters for Mobile IPv4 Bindings Flag 
    
   The only change to the Mobility Agent Advertisement Extension 
   defined in [1] is a flag indicating that the HA supports Filters for 
   Mobile IPv4 Bindings. The flag is inserted after the flags defined 
   in [5]. 
    
      0                   1                   2                   3 
      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 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |     Type      |    Length     |        Sequence Number        | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |           Lifetime            |R|B|H|F|M|G|V|T|S|I|N|reserved | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |     zero or more (collocated) care-of addresses               | 
      |                              ...                              | 
    
   The flag is defined as follows: 
    
        N   NOMADv4 Extension. This domain supports Filters for Mobile  
            IPv4 Bindings as specified in this document. 
    
Regional Registration Considerations 
    
 GFA/RFA Considerations 
 
   All Filtering Requests with the aim of defining, updating or 
   deleting Filters must be handled as Home Registrations and be 
   forwarded all the way to the HA. RFAs and GFAs receiving Filtering 
   Requests with the aim of transferring known Filters between mobility 
   bindings must issue a Filtering Reply and avoid forwarding to the 
   HA. 
    
    
7 NOMADv4 Extensions to RFC3344 Registration Messages 
    
   In this section the new Mobile IPv4 registration extensions required 
   for the support of Filters for Mobile IPv4 bindings are specified. 
    
   In NOMADv4, twelve types of extensions are defined. To form a valid 
   Filter, at least one of the extensions 1 to 9, termed as Filter 
   Modules, must be included. Extension 10 must appear once in every 
   Filter following all Filter Modules. Extension 11 may appear only 
   once in a Filtering Request after any Filter declarations. Finally, 
   extension 12 may appear several times within a Filtering Reply. 
    
     
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   Filter Modules of the same type may not appear in a Filter more than 
   once. However, a Filter Module may include one or more predicates. 
   There is an OR relationship between Filter Module predicates. That 
   is, in order for a flow to match a Filter Module it is required to 
   qualify for any of its predicates. In addition, there is an AND 
   relationship between Filter Modules of a Filter. As such, in order 
   for a flow to match a Filter it is required to qualify for all its 
   Filter Modules.  
    
   All extensions defined in this document follow the short extension 
   format defined in [1]. In Filter Modules, the leftmost bit of the 
   Sub-Type field is used to determine whether the rules included in 
   the Filter Module are positive or negative. In the first case a flow 
   is required to match exactly the predicates included in the Filter 
   Module while in the second, the inverted (NOT) rule. 
    
   1. Behavior Aggregate Filters Extension (BAF) 
      Specifies to Filters data packets dependent of the content of the 
      DSCP field. 
    
   2. Protocol Extension 
      Specifies one or more protocols to be filtered. 
    
   3. Source Address Extension 
      Specifies one or more source adresses to be filtered. 
    
   4. Source Network Extension 
      Specifies one or more source networks (i.e. a interval of 
      IP addresses) to be filtered. 
    
   5. Source Port Extension 
      Specifies one or more source ports to be filtered. 
    
   6. Source Port Range Extension 
      Specifies one or more ranges of source ports to be filtered. 
    
   7. Destination Port Extension 
      Specifies one or more destination ports to be filtered. 
    
   8. Destination Port Range Extension 
      Specifies one or more ranges of destination ports to be filtered. 
    
   9. Free-Form Extension 
      It allows for the definition of complex Filters based on the 
      value of an area anywhere within a packet. The mobile node 
      is required to provide the packet offset, the qualifying 
      value as well as a mask. 
    
   10. Filter Control Extension 
       It contains a FilterÆs unique identifier, called the Index along  
       with the FilterÆs Weight factor. 
    
   11. Filter Deletion Extension 
       It contains a list of Filter Index numbers to be deleted. 
     
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   If a Filter contains a Protocol Extension with the Protocol field 
   set to the corresponding value for ICMP then the Filter may not 
   include any of the Filter Modules from 5-8 as they refer to sender 
   and receiver port numbers that are not applicable for ICMP. Should a 
   Filtering Agent receive a Filtering Request with that configuration 
   of Filtering Modules, it is required to issue a Filtering Reply with 
   a Filter Control Extension indicating the FilterÆs Index and the 
   error code INVALID SYNTAX (section 7.12). 
    
7.1 Behavior Aggregate Filters (BAF) Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |    Length     |I|  Sub-Type   |    DSCP   |RSV| 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Length    (N), where N is the number of DSCP entries 
    
         Sub-Type  0 for given predicates, 128 for inverted predicates. 
    
         I (INVERT)A single bit at the beginning of the Sub-Type field  
                   used to invert predicates of Filter Module. Due to  
                   this bit two different Sub-Type values are given. 
    
         DSCP      Differentiated Services CodePoint 
    
   In Differentiated Services (DS) [7] the DS header field is defined 
   as a replacement for the IPv4 TOS [6] octets. Six bits of the DS 
   field are used as a codepoint (DSCP) to select the per-hop-behavior 
   that a packet receives at each node. For the purposes of NOMADv4 the 
   DSCP along with other header fields is used to construct Filters 
   that identify a specific flow or groups of them. 
    
   This Filter Module does not in any way alter or affect the DSCP 
   value of intercepted packets. 
    
7.2 Protocol Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |    Length     |I|  Sub-Type   |   Protocol    | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Length    (N), where N is the number of Protocol fields 
    
     
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         Sub-Type  1 for given predicates, 129 for inverted predicates 
    
         I (INVERT)A single bit at the beginning of the Sub-Type  
                   field used to invert predicates of Filter Module.  
                   Due to this bit two different Sub-Type values are  
                   given. 
    
         Protocol  Identifies the next level protocol used in the data 
                   portion of the internet datagram. The values for  
                   various protocols are specified in [4]. 
    
7.3 Source Address Extension 
    
   The Source Address Extension is defined for IPv4 and IPv6. 
    
      0                   1                   2                   3 
      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   
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |I|  Sub-Type   |             Length            | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |                       Source IP Address                       | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Length    (4*N), where N is the number of source IP address  
                   Fields. 
    
         Sub-Type  2 for given predicates, 130 for inverted predicates. 
    
         I (INVERT)A single bit at the beginning of the Sub-Type field  
                   used to invert predicates of Filter Module. Due to  
                   this bit two different Sub-Type values are given. 
    
   Source IP Address 
                   Identifies the source IP address contained in the IP  
                   header of an incoming flow. 
    
7.4 Source Network Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |I|  Sub-Type   |             Length            | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |                       Source IP Address                       | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |                     Source IP Address Mask                    | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
     
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         Sub-Type  3 for given predicates, 131 for inverted predicates. 
    
         I (INVERT)A single bit at the beginning of the Sub-Type  
                   field used to invert predicates of Filter Module.  
                   Due to this bit two different Sub-Type values are  
                   given. 
    
         Length   (8*N), where N is the number of pairs of a 
                   source IP address and a corresponding source 
                   IP address mask entry. 
    
   Source IP Address 
                   Identifies the base network IP address of a range of  
                   source IP addresses. 
    
   Source IP Address Mask 
                   Based on the source IP address field, identifies the  
                   range of source IP addresses. 
    
7.5 Source Port Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |I|  Sub-Type   |             Length            | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |          Source Port          | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Sub-Type  4 for given predicates, 132 for inverted predicates. 
    
         I (INVERT)A single bit at the beginning of the Sub-Type  
                   field used to invert predicates of Filter Module.  
                   Due to this bit two different Sub-Type values are  
                   given. 
    
         Length    (2*N), where N is the number of port entries. 
    
         Source Port 
                   Identifies the source port number contained in the 
                   IP header of an incoming flow. 
    
7.6 Source Port Range Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |I|  Sub-Type   |             Length            | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |        Source Port Min        |        Source Port Max        | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     
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         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Sub-Type  5 for given predicates, 133 for inverted predicates. 
    
         I         Invert. A single bit at the beginning of the Sub-
   Type  
                   field used to invert predicates of Filter Module.  
                   Due to this bit two different Sub-Type values are  
                   given. 
    
         Length    (4*N), where N is the number of port range entries. 
    
         Source Port Number Min 
                   Defines the start point of a range of source port 
                   numbers. 
    
         Source Port Number Max 
                  Defines the end point of a range of source port  
                  Numbers. 
    
7.7 Destination Port Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |I|  Sub-Type   |             Length            | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |        Destination Port       | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Sub-Type  6 for given predicates, 133 for inverted predicates. 
    
         I (INVERT)A single bit at the beginning of the Sub-Type  
                   field used to invert predicates of Filter Module.  
                   Due to this bit two different Sub-Type values are  
                   given. 
    
         Length    (2*N), where N is the number of port entries 
    
         Destination Port 
                   Identifies the destination port number contained in  
                   the IP header of an incoming flow. 
    
7.8 Destination Port Range Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |I|  Sub-Type   |             Length            | 
     
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     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |      Destination Port Min     |      Destination Port Max     | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Sub-Type  7 for given predicates, 134 for inverted predicates. 
    
         I (INVERT)A single bit at the beginning of the Sub-Type  
                   field used to invert predicates of Filter Module.  
                   Due to this bit two different Sub-Type values are  
                   given. 
    
         Length    (4*N), where N is the number of port range entries 
    
         Destination Port Number Min 
                   Defines the start point of a range of destination  
                   port numbers 
    
         Destination Port Number Max 
                   Defines the end point of a range of destination port 
                   numbers 
    
7.9 Free-Form Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |I|  Sub-Type   |             Length            | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |             Offset            |              Value              
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
                                   .... 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |                              Mask                               
                                   .... 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Sub-Type  7 for given predicates, 134 for inverted predicates. 
    
         I (INVERT)A single bit at the beginning of the Sub-Type  
                   field used to invert predicates of Filter Module.  
                   Due to this bit two different Sub-Type values are  
                   given. 
    
         Length    Is variable, depends on the length of Value and  
                   Mask. 
    
         Offset    Indicates a location within a packet to be filtered 
                   in bytes. 
    
     
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   The area indicated by the offset and for a length equivalent to that 
   of Mask is compared against Mask with the bitwise operator AND. The 
   result of this operation is compared against Value. A match would 
   indicate that the packet qualifies the filter. 
    
   Value and Mask fields MUST have exactly the same size. However, this 
   size may vary with every free-form filter. For the sizes of Value 
   and Mask the following condition holds: 
    
   Value = Mask = (Length - 2) / 2 
    
7.10 Filter Control Extension 
    
      0                   1                   2                   3 
      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 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |    Sub-Type   |    Length     |     Index     | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |    Weight     | 
     +-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Sub-Type  125. 
    
         Length    2. 
    
         Index     FilterÆs index number 
    
         Weight    Relative amount of traffic for which forwarding  
                   Filter is applicable 
    
7.11 Filter Deletion Extension 
    
      0                   1                   2       
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |    Sub-Type   |     Index     | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Sub-Type  126 
    
         Length    N, where N is the number of Index entries 
    
         Index     A FilterÆs index number 
    
7.12 Filter Reply Extension 
    
      0                   1                   2                   3 
      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 
     
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     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Type      |    Sub-Type   |    Length     |      Code     | 
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
     |     Index     | 
     +-+-+-+-+-+-+-+-+ 
    
         Type      The type, which describes a collection of extensions 
                   having a common data type. (To Be Defined). 
    
         Sub-Type  127. 
    
         Length    2. 
    
         Index     A FilterÆs index number. 
    
    
 Code Values for Filter Reply Extension 
    
   In this section the values to use within the Code field of the 
   Filter Control Extension are defined: 
    
   Successful Filtering Request Codes: 
    
         Code Name                Value   Section of Document 
         ----------------------   -----   ------------------- 
         REQUEST ACCEPTED         TBD 
    
   Failed Filtering Request Codes: 
    
         Error Name               Value   Section of Document 
         ----------------------   -----   ------------------- 
         NO FILTERS               TBD 
         TOO MANY FILTERS         TBD 
         INVALID FILTER SYNTAX    TBD 
         UNKNOWN FILTER           TBD 
         CAN NOT DROP MIP SIG     TBD 
    
   The Error Code CAN NOT DROP MIP SIG is used when the mobile node 
   issues a Filtering Request requesting the drop of flows 
   corresponding to Mobile IPv4 signaling such as Agent Advertisements 
   or Registration Requests and Replies. 
    
    
8 Intellectual Property Considerations 
    
   This proposal is in full conformity with [9]. 
    
   Siemens may have patent rights on technology described in this 
   document which employees of Siemens contribute for use in IETF 
   standard discussions. In relation to any IETF standard incorporating 
   any such technology, Siemens hereby agrees to license on fair, 
   reasonable and non-discriminatory terms, based on reciprocity, any 
   patent claims it owns covering such technology, to the extent such 
   technology is essential to comply with such standard. 
     
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8 Acknowledgements 
    
   The editor of this document would like to thank Mrs. Koojana 
   Kuladinithi for her precious input to this version of the draft. In 
   addition, the authors would like to thank all reviewers for their 
   help. 
    
    
References 
    
[1]     C. Perkins. IP Mobility Support. RFC (Proposed Standard) 3344,  
        IETF, August 2002. 
[2]     S. Bradner. Key words for use in RFCs to Indicate Requirement  
        Levels. RFC 2119, IETF, March 1997. 
[3]     C. Perkins and D. Johnson. Route Optimization in Mobile IP. 
        (work in progress). draft-ietf-mobileip-optim-11.txt, 
        IETF, September 2001. (expired; not updated) 
[4]     J. Reynolds and J. Postel. Assigned Numbers. Request for 
        Comments 1700, STD 2, IETF, October 1994. 
[5]     E. Gustafsson, A. Jonsson and C. Perkins. Mobile IP Regional  
        Registration. (work in progress). 
        draft-ietf-mobileip-reg-tunnel-07.txt, IETF, October 2002. 
[6]     Postel, J. Internet Protocol. STD 5, RFC 791, IETF, 
        September 1981. 
[7]     K. Nichols, S. Blake, F. Baker, and D. Black. Definition of 
        the Differentiated Services Field (DS Field) in the IPv4 and 
        IPv6 Headers. RFC 2474, IETF, December 1998. 
[8]     S. Deering and R. Hinden, Internet Protocol, Version 6 (IPv6)  
        Specification. RFC 2460, IETF, December 1998. 
[9]     S. Brander. The Internet Standards Process -- Revision 3. RFC  
        2026, IETF, October 1996 
 
 
A. Changes from Previous Versions 
    
   The following updates and changes were made in this version of the 
   Filters for Mobile IPv4 Bindings draft, compared to earlier 
   versions. 
    
A.1. Updates from version 02 
    
   Version 3 is almost a complete rewrite of version 2, based on 
   experience acquired from the implementation of version 2. 
    
   Renamed Binding Agents to Filter Agents and Binding Requests & 
   Replies to Filtering Requests & Replies. 
    
     
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   Defined in section 3.2 Model of operation that a mobile node may not 
   maintain more then one points of attachment in a single subnetwork. 
   Should the mobile node acquire one point of attachment in the home 
   network then all other must be given up. 
    
   Defined in section 3.1 Protocol Description and in the beginning of 
   section 5 NOMADv4 Extensions to RFC3344 Registration Messages the 
   structure of a Filter and the relation between Filter Module 
   predicates, Filter Modules and Filters. In addition, the Filter 
   Control Extension was renamed as Filter Target Extension while a new 
   extension by the name Filter Control Extension was defined. Removed 
   Action field from Filter Target Extension and increased Target and 
   Index fields to occupy 8 bits. 
    
   Removed P and A bits from Free Form Filter. 
    
   Added section 4 Backwards compatibility with RFC3344 
    
   Extended section on Mobile Node Considerations and Filtering Agent 
   Considerations in section 5 Associating Filters with Mobility 
   Bindings. Described specific actions undertaken by mobile node. 
    
   Renamed Default Binding to Default Filter and redefined it. Now 
   Fitlerless mobility bindings may not be Default Bindings. 
    
   Clarified that Index number denotes priority. 0 is lowest priority. 
   Index 0 is reserved for Default Filter. 
    
   Introduced the Filter Reply Extension for the relay of success and 
   error codes from Filtering Agents to mobile nodes. Defined success 
   and error codes. 
    
   Included INVERT flag in Filter Modules. 
    
   Introduced destination port and destination port range Filter 
   Modules. 
    
   Remove all reference to Filters for Mobile IPv6 bindings as this be 
   the purpose of a separate Internet draft. 
    
A.2. Updates from version 03 
    
   Removed all reference to Mobile IPv4 routing optimization. 
    
   Merged the Filter Target and Filter Control Extensions. 
    
   Introduced the æNÆ bit in the Registration Request and Reply 
   messages. 
    
   Removed the Target field from the Filter Control Extension 
    
   Introduced the Weight field in the Filter Control Extension. 
    
   Introduced the Filter Deletion Extension 
     
   NOMADv4               Expires January 2004                       24 
   Internet Draft     Filters for Mobile IPv4 Bindings       July 2003 
    
    
Authors' Addresses 
    
   Niko A. Fikouras 
   Department of Communication Networks (ComNets) 
   Center for Information and Communication Technology (ikom) 
   University of Bremen         Phone:  +49-421-218-3339 
   D-28219 Bremen, Germany      Email:  niko@comnets.uni-bremen.de 
    
   Asanga Udugama 
   Department of Communication Networks (ComNets) 
   Center for Information and Communication Technology (ikom) 
   University of Bremen         Phone:  +49-421-218-8665 
   D-28219 Bremen, Germany      Email:  adu@comnets.uni-bremen.de 
    
   Carmelita Goerg 
   Department of Communication Networks (ComNets) 
   Center for Information and Communication Technology (ikom) 
   University of Bremen         Phone:  +49-421-218-2277 
   28219, Bremen, Germany       Email:  cg@comnets.uni-bremen.de 
    
   Wolfgang Zirwas 
   Siemens AG 
   ICM N MR-ST 8 
   Werner-von-Siemens Ring 20 
   D-85630 Grasbrunn            Phone:  +49-89-722-34369 
   Germany                      Email:  wolfgang.zirwas@icn.siemens.de 
    
   Josef Martin Eichinger 
   Siemens AG 
   ICM N PG SP RC FR 
   Gustav-Heinemann Ring 11 
   D-81730 M’nchen              Phone:  +49-89-636 44838 
   Germany                      Email:  josef-m.eichinger@siemens.com 
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
     
   NOMADv4               Expires January 2004                       25 
   Internet Draft     Filters for Mobile IPv4 Bindings       July 2003 
    
    
     
   NOMADv4               Expires January 2004                       26 

PAFTECH AB 2003-20262026-04-22 23:18:42