Re: I-D Action: draft-ietf-dmm-requirements-07.txt

Sri,

Regarding your comments on the requirements, the motivation of REQ2 has been revised in version 08. The responses to your comments are in-line.  Please check.

5.2.  Transparency to Upper Layers when needed

   REQ2:  Transparency to Upper Layers when needed

          DMM solutions MUST provide transparent mobility support above
          the IP layer when needed.  Such transparency is needed, for
          example, when, upon change of point of attachment to the
          network, an application flow cannot cope with a change in the
          IP address.  However, it is not always necessary to maintain a
          stable home IP address or prefix for every application or at
          all times for a mobile node.

          Motivation: The motivation of this requirement is to enable
          more efficient routing and more efficient use of network
          resources by selecting an IP address or prefix according to
          whether mobility support is needed and by not maintaining
          context at the mobility anchor when there is no such need.

   This requirement addresses the problem PS5 as well as the related
   problem PS6 stated in Section 4.

The following have contributed to the revisions in draft 08: Pierrick, Dapeng, and Jouni


From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Sri Gundavelli (sgundave)
Sent: Sunday, August 25, 2013 10:04 PM
To: [email protected]<mailto:[email protected]>
Subject: Re: [DMM] I-D Action: draft-ietf-dmm-requirements-07.txt

Please see inline for some comments.


5.  Requirements



   After comparing distributed mobility management against centralized

   deployment in Section 3, this section identifies the following

   requirements:



5.1.  Distributed processing



   REQ1:  Distributed processing



          IP mobility, network access and routing solutions provided by

          DMM MUST enable distributed processing for mobility management

          so that traffic does not need to traverse centrally deployed

          mobility anchors and thereby avoid non-optimal routes.



          Motivation: This requirement is motivated by current trends in

          network evolution: (a) it is cost- and resource-effective to

          cache and distribute content by combining distributed mobility

          anchors with caching systems (e.g., CDN); (b) the

          significantly larger number of mobile nodes and flows call for

          improved scalability; (c) single points of failure are avoided

          in a distributed system; (d) threats against centrally

          deployed anchors, e.g., home agent and local mobility anchor,

          are mitigated in a distributed system.



   This requirement addresses the problems PS1, PS2, PS3, and PS4

   described in Section 4.  (Existing route optimization is only a host-

   based solution.  On the other hand, localized routing with PMIPv6

   addresses only a part of the problem where both the MN and the CN are

   located in the PMIP domain and attached to a MAG, and is not

   applicable when the CN is outside the PMIP domain.)



[Sri] I'm still stuck on the CDN example driving this requirement.



The requirements are general. In addition, whether specific solutions are sufficient is the role of the separate draft on gap analysis



5.2.  Transparency to Upper Layers when needed



   REQ2:  Transparency to Upper Layers when needed



          DMM solutions MUST provide transparent mobility support above

          the IP layer when needed.  Such transparency is needed, for

          example, when, upon change of point of attachment to the

          network, an application flow cannot cope with a change in the

          IP address.  However, it is not always necessary to maintain a

          stable home IP address or prefix for every application or at

          all times for a mobile node.





[Sri] Please reflect the two key aspects of this requirement:

*        Network can assign IP addresses with different properties; It carries those properties

*        Applications have different requirements and will pick the address with the correct property.



          Motivation: The motivation of this requirement is to enable

          more efficient use of network resources and more efficient

          routing by not maintaining context at the mobility anchor when

          there is no such need.

   This requirement addresses the problem PS5 as well as the related

   problem PS6 stated in Section 4.

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