One document matched: draft-singh-autoconf-adp-02.txt
Differences from draft-singh-autoconf-adp-01.txt
MANET Autoconfiguration (AUTOCONF) S. Singh
Internet-Draft J. Kim
Expires: April 23, 2006 Samsung AIT, Comm Lab
C. Perkins
Nokia Research Center,
Communications Systems Laboratory
T. Clausen
LIX, Ecole Polytechnique
P. Ruiz
University of Murcia
October 24, 2005
Ad hoc network autoconfiguration: definition and problem statement
draft-singh-autoconf-adp-02
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of 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 August 5, 2005.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
A Mobile Ad Hoc NETwork (MANET) is formed by the association of
Singh, et al. Expires August 5, 2005 [Page 1]
Internet-Draft ADP February 2005
mobile devices, usually wireless and capable of multi-hop
communication among themselves even if there is no networking
infrastructure available. MANET properties such as multi-hop,
autonomous, etc requires separate autoconfiguration mechanism. This
document gives definition, problem statement and goals
for ad hoc network autoconfiguration.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Problem statement . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Stand-alone ad hoc network . . . . . . . . . . . . . . . . 7
4.2. Ad hoc network at the edge of infra-structure network . . 8
4.3. Temporarily hybrid ad hoc network . . . . . . . . . . . . 9
4.4. Network merger and partitioning . . . . . . . . . . . . . 9
5. Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
Appendix A. Normative References . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
Intellectual Property and Copyright Statements . . . . . . . . . . 14
Singh, et al. Expires August 5, 2005 [Page 2]
Internet-Draft ADP February 2005
1. Introduction
A Mobile Ad Hoc NETwork (MANET) is formed by the association of
mobile devices, usually wireless and capable of multi-hop
communication among themselves even if there is no networking
infrastructure available. However, it is generally expected that, if
some MANET nodes are connected to external IP networks (e.g.
Internet), they might act as gateways towards those networks.
Several independent solutions have been proposed on interconnecting
MANETs and the Internet[4][5][7]. Most of the solutions are tightly
related to the issue of discovering Internet gateways and auto-
configuring global addresses that are routable within the Internet.
Usually, autoconfiguration of addresses in MANET is also required
even when the MANET is isolated from external networks.
Currently there is no standard definition for commonly used MANET
autoconfiguration related terminologies such as standalone MANET,
MANET local address, etc. This document provides definition of these
terminologies, in addition to problem statement and goals
for ad hoc network autoconfiguration.
Singh, et al. Expires August 5, 2005 [Page 3]
Internet-Draft ADP February 2005
2. Terminology
The keywords "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 [5].
Mobile Ad hoc Network (MANET) Mobile Ad hoc Network (MANET) - A
network formed dynamically in an arbitrary manner by a collection
of mobile devices equipped with one or more wireless interfaces.
Normally, nodes are characterized by random mobility and support
multi-hop communication. Multi-hop property requires that each
node should act as a "host" as well as a "router". Network
topology is dynamic in nature due to the mobile nature of MANET
nodes.
MANET Node - A device with one or more wireless interfaces and
associated IP address(es) which is used by the MANET routing
protocol in use.
MANET local address - An IP address configured on a MANET node and
valid for communication among MANET nodes that are part of the
same ad hoc network. Nodes MUST NOT communicate with other nodes
outside the MANET using this address.
Global address - An IP address configured on a MANET node and valid
for communication among MANET nodes as well as with the nodes
located on the Internet.
Internet gateway - An edge node connected to MANET as well as to the
Internet and capable of providing global addresses and
bidirectional connectivity to MANET nodes. Internet gateways
should provide topologically correct IPv6 prefixes. Internet
gateway mostly runs ad hoc routing protocols as well as
infrastructure network protocols such as OSPF.
Duplicate Address Detection (DAD) - The process by which a node
confirms the uniqueness of an address it wishes to configure or
has already configured. A node already equipped with an IP
address participates in DAD in order to protect its IP address
from being used by another node.
Standalone ad hoc network - A network formed by a group of MANET
nodes capable of spontaneously forming a multi-hop ad hoc network
and has no connection (either direct of via gateways) to other IP
networks such as the Internet.
Singh, et al. Expires August 5, 2005 [Page 4]
Internet-Draft ADP February 2005
Hybrid ad hoc network - A network formed by a group of MANET nodes,
capable of spontaneously forming a multi-hop ad hoc network, in
which one or more of the nodes act as Internet Gateways providing
access to other the Internet. They can be envisioned as a
standalone MANET with one or more Internet Gateways taking part in
both MANET and the Internet.
Network merger - The process by which two or more ad hoc networks
(either standalone or hybrid), previously disjoint, get connected.
In general, this proccess happens as a consequence of the node
mobility.
Network partitioning - The process by which an ad hoc network (either
standalone or hybrid) splits into two or more disconnected ad hoc
networks. In general, this proccess happens as a consequence of
the mobility of the nodes. When this happens, some of the routes
in MANET nodes become invalid hence some nodes may become
unreachable.
Network merger detection - The process by which MANET nodes detect
"network merger.
Network partition detection - The process by which MANET nodes detect
network partition.
Singh, et al. Expires August 5, 2005 [Page 5]
Internet-Draft ADP February 2005
3. Assumptions
o Routes between nodes in the ad hoc network MUST NOT leak into the
Internet.
o Network routes (those valid for an entire network prefix instead
of just a single node) require reachability to every node which
exists within the prefix, just as within the Internet.
o A gateway can be treated as a default router for the Internet.
o A gateway SHOULD maintain active routes for all nodes within the
MANET which are actively engaged in communications with their
partners in the Internet.
o Nodes within the Internet cannot distinguish whether or not a
gateway offers connectivity to an ad hoc network or some other
sort of stub network.
o If two gateways advertise connectivity to the same routing prefix,
then those two gateways MUST coordinate their routing tables so
that they exhibit equal reachability for all nodes within that
routing prefix.
o Multiple gateways may offer several different routing prefixes. A
node may choose which gateway's routing prefix to use for
autoconfiguration according to any convenient criterion; the
methods for making the determination are not constrained to be
only those specified within a MANET autoconfiguration protocol
specification.
o Autoconfigured addresses are likely to have lifetimes associated
with them, and after the lifetime expires use of the address
should be immediately discontinued.
o When duplicate addresses are detected, the node which has had the
address for the least amount of time MUST discontinue.
Alternatively, BOTH nodes MUST discontinue using this address.
Singh, et al. Expires August 5, 2005 [Page 6]
Internet-Draft ADP February 2005
4. Problem statement
Several specifications have been developed for address
autoconfiguration in the traditional IP based network e.g. RFC 2462,
RFC 2461, RFC 3315, etc. However, these specifications cannot be
used as-is by the MANET nodes due to their unique properties. Unlike
in traditional IP networks, each MANET node, besides being traffic
end-point, normally expected to be capable of forwarding traffic
traffic destined for other hosts i.e each ad hoc node normally acts
as a "router" as well as a "host". Additionally, the notion of all
nodes being able to access a shared communication medium fails in
MANET; since all nodes in a MANET do not share the same physical
link. In MANET, a single transmission does not suffice for a
broadcast or link-local multicast to reach all nodes. Transmissions
which are otherwise not supposed to be forwarded by routers, such as
limited broadcast and link-local multicast, are forwarded by the
nodes in order to reach all the MANET nodes. In other words, nodes
constituting an ad-hoc network do not share access to a single
multicast-capable link for signaling. The address autoconfiguration
related protocol specifications such as RFCs 2462, 2461, etc as used
in traditional IP networks, assume that subnet-local signals (e.g.
link-local multicast signals) are received by each of the hosts on
the particular subnet without being forwarded by the routers defining
the subnet boundary.
Ad hoc networks can either be deployed as an standalone MANET or as
an edge network, attached to the Internet. Indeed, IETF MANET WG has
this point of view for developing the MANET routing protocols.
There is a growing requirement for a standard address
autoconfiguration solutions in the MANET environment that can be used
by MANET nodes constituting standalone networks as well as edge
networks. However, the solutions should be designed with a minimal
modification, if any, and should be compliant with the specifications
that are widely used in the traditional IP networks.
The autoconfiguration protocol has to carefully distinguish between
cases when a gateway offers a routing prefix, from the case when a
"local" prefix has to be used since no routing prefix is available
for the purpose. In this way, a single addressing solution is
obtained, but just as within the Internet there are different kinds
of addresses. However, there may be differences which are discovered
as more development occurs towards the specification of the address
autoconfiguration protocol.
4.1. Stand-alone ad hoc network
Examples of standalone ad hoc networks are conference-room networks,
Singh, et al. Expires August 5, 2005 [Page 7]
Internet-Draft ADP February 2005
battlefield networks, surveillance networKs, etc. For these
networks, IP address auto-configuration mechanism is needed.
These addresses should be routable only within the particular ad hoc
network and should be unique even in situations where two or more
networks, initially disjoint, merge together to form a single
network. Network merger can occur anytime and this makes the address
uniqueness maintenance quite challenging in such situations.
4.2. Ad hoc network at the edge of infra-structure network
H1
|
+---------------+
| Internet |
+---------------+
* *
* *
GW1* *
| GW2
| |
---N1 |
/ | |
N4 | N2--- N5
| |
N3-----------N6
Fig. 1: Hybrid ad hoc network connected to Internet.
Hybrid networks can be envisioned as an standalone network connected
to the Internet via one or more Internet Gateways. These gateways
are located between the two networks and are capable of providing
globally routable addresses as well as bi-directional connectivity to
the ad hoc nodes connected to it either directly (1-hop) or via one
or more intermediate nodes. These gateways may either be fixed or
mobile, single or multiple, equipped with wired and/or wireless
interfaces.
Fig.1. shows an ad hoc network deployed at the edge of the Internet.
Ad hoc nodes may use Internet gateway for global prefix allocation
and configuration of globally routable addresses. However, it
introduces issues such as how MANET nodes receive and/or Internet
gateway provides globally routable prefixes, etc. Hence, for such
network sufficient but limited detail about Internet gateway
discovery and operation is required, along with an address
autoconfiguration solution.
Singh, et al. Expires August 5, 2005 [Page 8]
Internet-Draft ADP February 2005
4.3. Temporarily hybrid ad hoc network
Temporarily hybrid MANET scenario arises due to the situation where
an ad hoc network may be sometimes stand-alone and sometimes
connected to the Internet e.g. a car or subway network connected
while parked or at station and disconnected otherwise.
Basically, the problems in this case are similar to those introduced
in the above two cases. However, in this case, ad hoc nodes should
detect the lack of reachability to the Internet and SHOULD maintain
their allocated addresses for the lifetime which has been assigned
during the autoconfiguration process. For local addresses, no such
lifetime is necessary, but could anyway be assigned as a minimal
protection against partitioning.
4.4. Network merger and partitioning
By the nature of MANET, two or more ad hoc networks which are
initially isolated, can merge together or a single ad hoc network can
get partitioned into two or more separate networks, at any moment in
time. While network partitioning may not cause any problem in the
MANET's operation, it may be needed that network partitioning is
detected so that the resources (e.g. limited number of addressed) can
be re-used among the nodes.
Network merger imposes challenges to maintain the address uniqueness.
Normally, once an address is allocated to a node, it continues using
it and at the same time defending its own address from being
allocated to any other node. However, since initially isolated
networks had allocated addresses independent with each other, there
remains some probability of more than one node using same address.
Worst possible scenario can occur when number of address conflicts
after merger are as many as number of nodes. This can happen if, for
example, addresses were allocated within initially independent MANETs
from the same address-range.
Singh, et al. Expires August 5, 2005 [Page 9]
Internet-Draft ADP February 2005
5. Goals
Goals listed below are by no means exhaustive. Additional goals may
be found necessary as the protocol design, implementation and
deployment takes place. Below listed goals is an effort to
give a bigger scope and as such may or may not fall within the scope
of the AUTOCONF WG. These goals include:
- As mentioned in the above sections, MANETs can be either
standalone or connected to the Internet via one or more Internet
gateways. MANET nodes MUST implement a mechanism to
configure "local address(es)" when standalone. It MAY also configure
global address(es) when connected to the Internet. Nodes MUST
ensure address uniqueness, explained under next bullet, before
configuring them to their interfaces. It MAY be required that
the configured global addresses are usable even after connectivity
with the Internet is lost.
- Each node MUST perform duplicate address detection test on
addresses before configuring them to their interfaces - ensuring
uniqueness of the tentative addresses. If the particular address
is being used by some other node, either or both nodes MUST not
use the address. In this situation an alternative address MAY be
generated and tested for uniqueness.
- As mentioned in section 4.4, network Merger is quite possible in
MANETs. This may or may not result in multiple nodes using same
address. However, each node SHOULD run a mechanism to ensure the
uniqueness of its current address-in-use.
- Network partitioning is equally probably scenario in MANET.
While network partitioning may not cause any problem in the
MANET's ongoing operation, it MAY be needed that network
partitioning is detected so that the resources such as
IP addresses can be re-used among the nodes. Hence,
MANET nodes MAY need a mechanism, either independent or
integrated with the the main protocol, to detect network
partitioning.
- Protocol should be designed to avoid as many security pitfalls
as can be avoided. This may involve using collaboration histories
and out-of-band mechanisms requiring user interventions.
Singh, et al. Expires August 5, 2005 [Page 10]
Internet-Draft ADP February 2005
6. Security Considerations
Since this document does not specify any protocol, no additional
security vulnerabilities are created. However, experience with other
address autoconfiguration protocols indicates that it is difficult to
expect a very high degree of security. This is especially true in an
ad hoc network using manet-local addresses, since it may be
unfeasible to interact with any pre-existing security infrastructure.
Nevertheless, the protocols should be designed to avoid as many
security pitfalls as can be avoided. This may involve using
collaboration histories and out-of-band mechanisms requiring user
interventions.
Singh, et al. Expires August 5, 2005 [Page 11]
Internet-Draft ADP February 2005
Appendix A. Normative References
o [1] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
o [2] Thomson, S. and T. Narten, "IPv6 Stateless Address
Autoconfiguration", RFC 2462, December 1998.
o [3] Engelstad, P., Tonnesen, A., Hafslund, A. and G. Egeland,
"Internet Connectivity for Multi-Homed Proactive Ad Hoc Networks",
First IEEE International Conference on Sensor and Ad hoc
Communications and Networks, October 2004.
o [4] Ryuji Wakikawa et. al. Global connectivity for IPv6 Mobile Ad
Hoc Networks, IETF "draft-wakikawa-manet-globalv6-03.txt"
o [5] Shubhranshu Singh, Kim, JH., Choi, YG., Kang, KL. and YS.
Roh, "Mobile multi-gateway support for IPv6 mobile ad hoc
networks" I-D draft-singh-manet-mmg-00.txt, June 2004.
o [6] Perkins, C., Malinen, J., Wakikawa, R. and E. Belding-Royer,
"IP Address Autoconfiguration for Ad Hoc Networks", I-D
draft-perkins-manet-autoconf-01.txt, November 2001.
o [7] Cha, H., Park, J. and H. Kim, "Extended Support for Global
Connectivity for IPv6 Mobile Ad Hoc Networks", October 2003.
o [8] Jeong, J., Park, J., Kim, H. and D. Kim, "Ad Hoc IP Address
Autoconfiguration", I-D draft-jeong-adhoc-ip-addr-autoconf-02.txt,
February 2004.
o [9] Paakkonen, P., Rantonen, M. and J. Latvakoski, "IPv6
addressing in a heterogeneous MANET-network", I-D
draft-paakkonen-addressing-htr-manet-00.txt, December 2003.
o [10] Jelger, C., Noel, T. and A. Frey, "Gateway and address
autoconfiguration for IPv6 adhoc networks", I-D
draft-jelger-manet-gateway-autoconf-v6-02.txt, April 2004.
o [11] Sun, Y. and E. Belding-Royer, "A study of dynamic addressing
techniques in mobile ad hod networks", I-D Wireless communication
and mobile computing, May 2004.
o [12] Engelstad, P., Tonnesen, A., Hafslund, A. and G. Egeland,
"Internet Connectivity for Multi-Homed Proactive Ad Hoc Networks",
First IEEE International Conference on Sensor and Ad hoc
Communications and Networks, October 2004.
Singh, et al. Expires August 5, 2005 [Page 12]
Internet-Draft ADP February 2005
Authors' Addresses
Shubhranshu Singh
Samsung AIT, Comm Lab, S. Korea
Phone: +82 31 280 9569
Email: Shubhranshu@gmail.com
JaeHoon Kim
Samsung AIT, Comm Lab, S. Korea
Phone: +82 31 280 9532
Email: jaehoonk@samsung.com
Charles E. Perkins
Nokia Research Center,
Comm Systems Laboratory, U.S.A
Phone: +1 650 625 2986
Email: charliep@iprg.nokia.com
Thomas Heide Clausen
LIX, Ecole Polytechnique, France
Phone: +33 6 6058 9349
Email: T.Clausen@computer.org
URI: http://www.lix.polytechnique.fr/Labo/Thomas.Clausen/
Pedro M. Ruiz
University of Murcia, Spain
Phone: +34 968367646
Email: pedrom@dif.um.es
Singh, et al. Expires August 5, 2005 [Page 13]
Internet-Draft ADP February 2005
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Disclaimer of Validity
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The Internet Society (2005). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
Singh, et al. Expires August 5, 2005 [Page 14]
| PAFTECH AB 2003-2026 | 2026-04-23 11:05:33 |