One document matched: draft-jeyatharan-netext-pmip-bulkpbu-bitmap-00.txt
NetExt Working Group M. Jeyatharan
Internet-Draft C. Ng
Intended status: Informational Panasonic
Expires: April 19, 2010 October 16, 2009
Bulk PBU using Bitmaps
draft-jeyatharan-netext-pmip-bulkpbu-bitmap-00
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 19, 2010.
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of
publication of this document (http://trustee.ietf.org/license-info).
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
Abstract
In Proxy Mobile Internet Protocol version 6 (PMIPv6), each mobile
node attached to a mobile access gateway (MAG) requires separate
signaling. This might result in excessive network signaling if there
Jeyatharan & Ng Expires April 19, 2010 [Page 1]
Internet-Draft BulkPBU-Bitmaps October 2009
a large number of mobile nodes attached to a MAG. In this draft we
outline a bulk PBU optimization approach based on bitmap, in order to
reduce the signaling load tied to numerous PBUs originating at the
same time.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Bulk PBU Optimization Approaches . . . . . . . . . . . . . . . 4
2.1. Conventional bulk PBU Approach . . . . . . . . . . . . . . 4
2.2. Bitmap based bulk PBU Approach . . . . . . . . . . . . . . 5
3. Synergy with other Approaches . . . . . . . . . . . . . . . . . 7
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.1. Normative Reference . . . . . . . . . . . . . . . . . . . . 8
6.2. Informative Reference . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8
Jeyatharan & Ng Expires April 19, 2010 [Page 2]
Internet-Draft BulkPBU-Bitmaps October 2009
1. Introduction
The Proxy Mobile IPv6 protocol (RFC-5213 [1]) allows a mobile access
gateway (MAG) to perform a PBU on behalf of a mobile node that is
served by the MAG. The PBU originating from the MAG can be of
different types such as initial registration PBU, handoff PBU, re-
registration PBU and de-registration PBU, all representing the
attachment state of a mobile node. If there are numerous mobile
nodes being served by the MAG, and each PBU associated with the
mobile node has multiple mobility options attached, then multiple
such PBUs originating from the MAG increases network signaling load.
It is preferable to reduce such signaling load for better network
operation and maintenance.
Rather than performing a simple concatenation of multiple PBUs tied
to multiple mobile nodes, a bulk PBU with only a single instance of a
given mobility option type attached and an additional bitmap option
used to locate the usage of the attached mobility option type by a
mobile node tied to the bulk PBU is described in this draft.
Conceptually, the bitmap is a matrix whose fields represent whether a
particular mobility option (can be mandatory or optional mobility
option) type is used by the mobile node that is tied to the bulk PBU.
Since bitmaps collapse multiple instances of a given mobility option
type (or value) to a single instance, it is considered as a
compressed identifier of multiple mobility options and hence provides
better optimization for bulk PBU. The bitmap based optimization
approach discussed in this draft is a general approach for bulk PBU
optimization, and it can be used at any instance when bulk PBU needs
to be sent from the MAG.
Although the bitmap based approach described in this draft can be
used independently to optimize signaling efficiency, it can also be
used with other bulk PBU approaches as well. For instance, [2]
illustrates a PBU with MN group ID option attached that is used to
perform either bulk re-registration or bulk de-registration of the
mobile nodes that are grouped by a group ID. Additionally, [3] also
describes a similar approach which uses a bulk set ID option in the
PBU to perform bulk re-registration of multiple mobile nodes which
are reference by a single bulk set ID. As will be discussed later,
the bitmap based bulk PBU optimization approach described in this
draft can be used together with these approaches described in [2] and
[3].
Section 2 describes the conventional bulk PBU optimization approach
and bitmap based bulk PBU optimization approach. Following that in
Section 3, we illustrate how this bitmap based bulk PBU optimization
approach can be combined or interwork with the MN group ID mechanism
that is described in [2] and also briefly highlight the differences
Jeyatharan & Ng Expires April 19, 2010 [Page 3]
Internet-Draft BulkPBU-Bitmaps October 2009
between the bitmap based optimization approach the MN group ID based
optimization approach.
2. Bulk PBU Optimization Approaches
In this section, two bulk PBU optimization approaches are described.
The first one is the conventional bulk PBU optimization approach or
conventional approach and the second one is the bitmap based bulk PBU
optimization approach. The conventional bulk PBU optimization
approach is mainly described to understand the benefits tied the
bitmap approach.
2.1. Conventional bulk PBU Approach
The conventional way of combining multiple PBU messages for different
mobile nodes is to have a single IPv6 header and a single PBU
mobility header, and insert all the mobility options for each mobile
node into the bulk PBU message. This takes advantage of sequential
processing of the bulk PBU message at the LMA, as if multiple
individual PBU messages are being processed. In such an arrangement,
the mobility options associated with each mobile node are inserted
into the PBU message together sequentially, with the Mobile Node
Identifier option inserted first. Hence, it can be treated as if the
appearance of a Mobile Node Identifier option signals the start of
another individual PBU (which shares the same PBU mobility header).
For example, the bulk PBU for mobile nodes MN1 and MN2 will appears
as follows:
IPv6 Header
Mobility Header
PBU Header
Mobility Options
Mobile Node Identifier option for MN1
Other mobility options for MN1
Mobile Node Identifier option for MN2
Other mobility options for MN2
The main disadvantage of this approach is that although there is
packet size savings in terms of the number of IPv6 headers and the
number PBU mobility headers (only one IPv6 header and one PBU
mobility header), the mobility options of the same type (or value)
are repeated in the bulk PBU message. For example, one of MN1's
mobility option can be Handoff Indicator option of value "2" and the
MN2 may also use the same Handoff Indicator option with the same
value "2". This may lead to the resulting bulk PBU packet size being
too big, and thus the packet may be dropped en-route or will need to
be broken into multiple PBU messages to overcome the path MTU.
Jeyatharan & Ng Expires April 19, 2010 [Page 4]
Internet-Draft BulkPBU-Bitmaps October 2009
2.2. Bitmap based bulk PBU Approach
The bitmap approach is such that only one mobility option of a
certain type (or value) is attached to the bulk PBU message
regardless of the number of mobile nodes that are tied to the
message. Similar to the conventional approach, the bulk PBU message
will have only one IPv6 header and one PBU mobility header. After
the PBU mobility header, the mobility options will be attached. The
MAG will attach the union of all the mobility options used by all the
mobile nodes tied to the bulk PBU. To indicate the association of
the mobility options with each mobile node, a bitmap mobility option
will be attached in the bulk PBU.
To better illustrate this, we assume that a bulk PBU message will
contain registration for mobile nodes MN1, MN2 and MN3. It is
assumed that the mobility options for each mobile node are:
MN1:
Mobile Node Identifier option: MN1-ID
Access Technology Type option: ATT1
Home Network Prefix option: HNP=P1
Home Network Prefix option: HNP=P2
mobility option X
Handoff Indicator option: HI=1
MN2:
Mobile Node Identifier option: MN2-ID
Access Technology Type option: ATT2
Home Network Prefix option: HNP=P3
Home Network Prefix option: HNP=P4
mobility option X
Handoff Indicator option: HI=1
MN3:
Mobile Node Identifier option: MN3-ID
Access Technology Type option: ATT2
Home Network Prefix option: HNP=P5
mobility option Y
Handoff Indicator option: HI=2
Using the bitmap approach, the resulting PBU will be:
Jeyatharan & Ng Expires April 19, 2010 [Page 5]
Internet-Draft BulkPBU-Bitmaps October 2009
IPv6 Header
Mobility Header
PBU Header
Mobility Options
Mobile Node Identifier option: MN1-ID
Mobile Node Identifier option: MN2-ID
Mobile Node Identifier option: MN3-ID
Home Network Prefix option: HNP=P1
Home Network Prefix option: HNP=P2
Home Network Prefix option: HNP=P3
Home Network Prefix option: HNP=P4
Home Network Prefix option: HNP=P5
Handoff Indicator option: HI=1
Handoff Indicator option: HI=2
Access Technology Type option: ATT1
Access Technology Type option: ATT2
mobility option X
mobility option Y
Bitmap option = 11000101010 00110100110 00001010101
It can be seen that for certain type and value only single mobility
option is attached using the bitmap based approach. For example, if
conventional bulk PBU method of combining is used, then for HI and
ATT, 6 mobility options will be used. However, using the bitmap
approach only 4 mobility options to represent HI and ATT are used in
the bulk PBU message. The trick lies in the Bitmap option, which
indicates the association of each Mobile Node Identifier option with
the other mobility options. Figure 1 provides the illustration on
how the association is derived from the Bitmap option.
+=======================================================+
| | P1| P2| P3| P4 | P5|HI1 | HI2 | ATT1| ATT2 |X |Y |
|----|---|---|---|----|---|----|-----|-----|------|--|--|
| MN1| 1 | 1| 0| 0 | 0| 1 | 0 | 1 | 0 |1 |0 |
| MN2| 0 | 0| 1| 1 | 0| 1 | 0 | 0 | 1 |1 |0 |
| MN3| 0 | 0| 0| 0 | 1| 0 | 1 | 0 | 1 |0 |1 |
+=======================================================+
Figure 1: Bitmap Illustration
The LMA will use the bitmap shown in Figure 1 to determine the
mobility options associated to a particular mobile node. To obtain
the bitmap, the LMA will use the number of mobility options that are
not Mobile Node Identifier option in the PBU to determine the number
of columns in the bitmap and will use the number of Mobile Node
Identifier options to determine the number of rows. Each row then
contains the association information to form the binding cache entry
for each mobile node.
Jeyatharan & Ng Expires April 19, 2010 [Page 6]
Internet-Draft BulkPBU-Bitmaps October 2009
3. Synergy with other Approaches
The bitmap approach described in this draft is a general approach of
optimization and can work along with the mobile node group ID
approach described in [2] and [3] as well. Three such use cases are
outlined below to highlight such combined usage:
o Use Case 1: MAG sending a bitmap based bulk PBU to LMA and
requesting the LMA to associate the MNs to the attached MN group
identifier(s). For example, if there are mobile nodes MN1 and MN2
that are going to be tied to group GID1 and mobile nodes MN3 and
MN4 are going to be tied to group GID2, then the bitmap based bulk
PBU message will contain a union of all the mobile nodes related
mobility options, followed by Group Identifier options for GID1
and GID2. The bitmap option in the message will indicate the
association of each mobile node to the group IDs.
o Use Case 2: MAG sending mobility options for multiple groups in a
single bulk PBU. In this case, the bitmap option can indicate the
association of mobility options to each group (i.e. rows in the
bitmap matrix will contain the association information for each
group).
o Use Case 3: MAG sending a bulk PBU containing information
pertaining to both groups and un-grouped mobile nodes. Hence the
bulk PBU will contain Mobile Node Identifier options, Group
Identifier options, and other related mobility options. For
example, a bulk PBU may contain indications for newly handed over
mobile nodes and re-registration for existing groups of mobile
nodes. In such a combination, the bitmap matrix rows are tied to
the Mobile Node Identifier and Group Identifier options.
To differentiate between the three use cases, the bitmap option can
contain a flag to indicate whether (a) only Mobile Node Identifier
options, (b) only Group Identifier options, or (c) both Mobile Node
Identifier and Group Identifier options are used to as rows in the
derived bitmap matrix.
4. IANA Considerations
This memo highlights a need for a new mobility option to carry the
bitmap matrix and IANA needs to assign an appropriate type for it.
5. Security Considerations
The bitmap approach described in this memo highlights a need for a
Jeyatharan & Ng Expires April 19, 2010 [Page 7]
Internet-Draft BulkPBU-Bitmaps October 2009
new mobility option which will be tied to the PBU message and thus
the security considerations tied to PMIPv6 protocol as given in (RFC-
5213 [1]) applies here as well.
6. References
6.1. Normative Reference
[1] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and
B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
6.2. Informative Reference
[2] Gundavelli, S., Leung, K., Patil, B., and D. Premec, "Mobile
Node Group Identifier option",
draft-gundavelli-netext-mn-groupid-option-01 (work in progress),
June 2009.
[3] Premec, D., Patil, B., and S. Krishnan, "Bulk Re-registration
for Proxy Mobile IPv6",
draft-premec-netlmm-bulk-re-registration-02 (work in progress),
March 2009.
Authors' Addresses
Mohana Dahamayanthi Jeyatharan
Panasonic Singapore Laboratories Pte Ltd
Blk 1022 Tai Seng Ave #06-3530
Tai Seng Industrial Estate
Singapore 534415
SG
Phone: +65 65505494
Email: mohana.jeyatharan@sg.panasonic.com
Chan-Wah Ng
Panasonic Singapore Laboratories Pte Ltd
Blk 1022 Tai Seng Ave #06-3530
Tai Seng Industrial Estate
Singapore 534415
SG
Phone: +65 65505420
Email: chanwah.ng@sg.panasonic.com
Jeyatharan & Ng Expires April 19, 2010 [Page 8]
| PAFTECH AB 2003-2026 | 2026-04-23 20:38:27 |