Internet DRAFT - draft-acee-ospf-geo-location
draft-acee-ospf-geo-location
Network Working Group A. Lindem, Ed.
Internet-Draft N. Shen
Intended status: Standards Track E. Chen
Expires: April 21, 2018 Cisco Systems
October 18, 2017
OSPF Extensions for Advertising/Signaling Geo Location Information
draft-acee-ospf-geo-location-05.txt
Abstract
This document specifies an OSPF Router Information (RI) TLV to
advertise the current Geo Coordinates of the OSPF router. For Point-
to-Point (P2P)) and Point-to-Multi-Point (P2MP) networks, the Geo
Coordinates can be used to dynamically computing the cost to
neighbors. This is useful both from the standpoint of auto-
configuration and situations where the OSPF routers are moving. The
Geo Coordinates are also useful for other applications such as
Traffic Engineering (TE) and network management.
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Notation . . . . . . . . . . . . . . . . . . 2
2. OSPF Geo Coordinates TLV . . . . . . . . . . . . . . . . . . 2
3. Link Advertisement of the OSPF Geo-Coordinates . . . . . . . 4
4. OSPFv2 Router Information (RI) Opaque LSA . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 5
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
8.1. Normative References . . . . . . . . . . . . . . . . . . 6
8.2. Informative References . . . . . . . . . . . . . . . . . 6
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
This document specifies an OSPF Router Information (RI) [OSPF-RI] TLV
to advertise the current Geo Coordinates of the OSPF router. For
Point-to-Point (P2P)) and Point-to-Multi-Point (P2MP) networks, the
Geo Coordinates can be used to dynamically computing the cost to
neighbors. This is useful both from the standpoint of auto-
configuration and situations where the OSPF routers are moving. The
Geo Coordinates are also useful for other applications such as
Traffic Engineering (TE)and network management.
1.1. Requirements Notation
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-KEYWORDS].
2. OSPF Geo Coordinates TLV
The Geo Coordinates TLV can be used to advertise the current location
of an OSPFv2 [OSPF] or OSPFv3 [OSPFV3] router using the OSPF Router
Information LSA [OSPF-RI]. The OSPF Router Information LSA can be
advertised in both link-scoped and area or AS scoped RI LSAs. The
fields specify the location of the OSPF router using the WGS-84
(World Geodetic System) reference coordinate system [WGS84]. The
value of the Geo Coordinates TLV consists of the following fields:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|N|E|A|M|R|K| Reserved | Location Uncertainty |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lat Degrees | Latitude Milliseconds |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Long Degrees | Longitude Milliseconds |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Altitude |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Radius | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| .. Optional Sub-TLVs
+-+-+-+-+-+-+-+-+-....
Where:
U-bit: If the U-bit is set, it indicates that the "Location
Uncertainty" field is specified. If the U-bit is clear,
it indicates the "Location Uncertainty" field is
unspecified.
N-bit: If the N-bit is set, it indicates the Latitude is
north relative to the Equator. If the N-bit is clear,
it indicates the Latitude is south of the Equator.
E-bit: If the E-bit is set, it indicates the Longitude is east
of the Prime Meridian. If the E-bit is clear, it indicates
the Longitude is west of the Prime Meridian.
A-bit: If the A-bit is set, it indicates the "Altitude" field is
specified. If the A-bit is clear, it indicates the
"Altitude" field is unspecified.
M-bit: If the M-bit is set, it indicates the "Altitude" is
specified in meters. If the M-bit is clear, it indicates
the "Altitude" is in centimeters.
R-bit: If the R-bit is set, it indicates the "Radius" field is
specified and the encoding is for a circular area. If
the R-bit is clear, it indicates the "Radius" field is
unspecified and the encoding is for a single point.
K-bit: If the K-bit is set, it indicates the "Radius" is specified
in kilometers. If the K-bit is clear, it indicates the
"Radius" is in meters.
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Reserved: These bits are reserved. They SHOULD be set to 0 when
sending protocol packets and MUST be ignored when
receiving protocol packets.
Location Uncertainty: Unsigned 16-bit integer indicating the
number of centimeters of uncertainty for
the location.
Latitude Degrees: Unsigned 8-bit integer with a range of 0 - 90
degrees north or south of the Equator (northern
or southern hemisphere, respectively).
Latitude Milliseconds: Unsigned 24-bit integer with a range of
0 - 3,599,999 (i.e., less than 60 minutes).
Longitude Degrees: Unsigned 8-bit integer with a range of 0 - 180
degrees east or west of the Prime Meridian.
Longitude Milliseconds: Unsigned 24-bit integer with a range of
0 - 3,599,999 (i.e., less than 60 minutes).
Altitude: Signed 32-bit integer containing the Height relative to
sea level in centimeters or meters. A negative height
indicates that the location is below sea level.
Radius: Unsigned 16-bit integer containing the radius of a
circle centered at the specified coordinates. The radius
is specified in meters unless the K-bit is specified
indicating specification in kilometers. If the radius is
specified, the geo-coordinates specify the entire area
of the circle defined by the radius and center point.
While the use cases herein do not make use of this field,
future use cases may.
Optional Sub-TLVs: No additional Sub-TLVs are defined in this
document.
OSPF Geo Coordinates TLV
3. Link Advertisement of the OSPF Geo-Coordinates
When the Geo Coordinates are used for cost computation, the
coordinates need to be advertised on the link using the encoding
specified in Section 2. For this application, a link-scoped OSPF
Router Information (RI) [OSPF-RI] is advertised on each link where
geo-location cost computation is utilized.
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When an OSPF router receives the Geo Coordinates TLV in a link-scoped
OSPF RI LSA from an adjacent neighbor, it can be used to calculate
the physical distance to neighbor. For P2P and P2MP networks, this
distance can be used to dynamically compute the cost of the link to
that neighbor. The mapping of the distance to advertised cost is not
specified in this document. However, all OSPF routers in the domain
SHOULD used the same algorithm. Computation of cost based on
physical distance can be useful both for autoconfiguration of these
networks types and dynamic cost computation when the routers are
moving.
The Geo location information can be statically provisioned or
dynamically acquired from a GPS capable device on the OSPF Router.
4. OSPFv2 Router Information (RI) Opaque LSA
The OSPF Geo Coordinates TLV may optionally be advertised in the OSPF
Router Information (RI) LSA [OSPF-RI]. It then may be used for
applications such as traffic engineering (TE) and network management
(e.g., the Find-My-Router application). The details of such
applications are beyond the scope of this document.
5. Security Considerations
Since the Geo Location coordinates provide the exact location of the
OSPF router, disclosure will make the OSPF router more susceptible to
physical attacks. In situations where this is a concern (e.g.,
military applications), confidentiality should be provided either
through a secure tunnel (e.g., [IP-ESP]) or protocol encryption
[OSPFV3-AUTH].
Additionally, in some situations, the topology of the network is
considered proprietary information. With the Geo Location
coordinates, the physical topology, as well as the IP topology, can
be discerned from the OSPF Router Information (RI) LSA. In these
situations, confidentiality should be assured.
Security considerations for the base OSPF protocol are covered in
[OSPF] and [OSPFV3].
6. Privacy Considerations
If the location of an OSPF router advertising geo location
coordinates as described herein can be directly correlated to an
individual, individuals, or an organization, the location of that
router should be considered sensitive and OSPF RI LSAs containing
such geo coordinates should be advertised confidentially as described
in Section 5. Additionally, OSPF network management facilities may
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require added authorization to view the contents of OSPF RI LSAs
containing geo-Location TLVs. Refer to [PRIVACY] for more
information.
The Uncertainty and Confidence metrics for geo-location information
as described in [GEO-PIDF-LO] are not included in the Geo Coordinates
TLV. In a future document, these may be considered for inclusion
with additional Geo Location Sub-TLVs dependent on both on
requirements and adoption of [GEO-PIDF-LO].
7. IANA Considerations
The document will require the following IANA actions:
1. A Router Information TLV type for the Geo Location TLV will be
allocated from the OSPF Router Information (RI) TLVs registry.
8. References
8.1. Normative References
[OSPF] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
[OSPF-RI] Lindem, A., Shen, N., Vasseur, J., Aggarwal, R., and S.
Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 7770, January 2016.
[OSPFV3] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, July 2008.
[RFC-KEYWORDS]
Bradner, S., "Key words for use in RFC's to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
8.2. Informative References
[GEO-PIDF-LO]
Thomson, M. and J. Winterbottom, "Representation of
Uncertainty and Confidence in the Presence Information
Data Location Object (PIDF-LO)", RFC 7459, February 2015.
[IP-ESP] Kent, S., "IP Encapsulation Security Payload (ESP)", RFC
4303, December 2005.
[LISP-GEO]
Farinacci, D., "LISP Geo-Coordinate Use-Cases", draft-
farinacci-lisp-geo-03 (work in progress), April 2017.
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[OSPFV3-AUTH]
Gupta, M. and S. Melam, "Authentication/Confidentiality
for OSPFv3", RFC 4552, June 2006.
[PRIVACY] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
Morris, J., Hansen, M., and R. Smith, "Privacy
Considerations", RFC 6973, July 2013.
[WGS84] National Imagery and Mapping Agency, "Department of
Defense World Geodetic System 1984, Third Edition", NIMA
TR83500.2, January 2000.
Appendix A. Acknowledgments
The RFC text was produced using Marshall Rose's xml2rfc tool.
The encoding of the Geo location is adapted from "LISP Geo-
Coordinates Use-Cases" [LISP-GEO]. We would like to thank the
author, Dino Farinacci, for subsequent discussions.
Thanks to Yi Yang for review and discussions of the Geo Coordinate
encoding.
The use-case for using OSPF to advertise the geo-location in OSPF was
first mentioned in an OSPF operator-defined TLV draft by Uma
Chunduri, Xiaohu Xu, Luis M. Contreras, Mohamed Boucadair, and Luay
Jalil.
Authors' Addresses
Acee Lindem (editor)
Cisco Systems
301 Midenhall Way
Cary, NC 27513
USA
Email: acee@cisco.com
Naiming Shen
Cisco Systems
821 Alder Drive
Milpitas, CA 95935
USA
Email: naiming@cisco.com
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Enke Chen
Cisco Systems
821 Alder Drive
Milpitas, CA 95935
USA
Email: enkechen@cisco.com
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