Patent Application
20100002700
Methods and systems of the present disclosure relate generally to geographic-based packet routing in an Internet Protocol (IP) network and other networks.
Various routing methods are known for computer network packets. For example, U.S. Pat. No. 4,939,726 entitled “Method for routing packets in a packet communication network,” which is incorporated by this reference, describes forwarding packets from a source node to a target node via a series of intermediates using the target node's geographic coordinates, which are made part of or derived from the target node address that is included in the packet headers. Each intermediate node selects a successor node using, among other things, the maximum forward geographic progress attainable, which is determined by calculating a metric incorporating the geographical distance between the coordinates of the target node and the coordinates of each potential successor node. U.S. Pat. No. 5,636,216, entitled “Method for translating IP addresses to other distributed network addressing schemes,” which is incorporated by this reference, describes using a network specific local address of a target node that incorporates the target's geographic coordinates.
Certain embodiments of the invention provide systems and methods for network packet routing using geographic routing information that is embedded in the address of a packet. For example, certain embodiments provide a method for assigning an IP address for routing packets in an IP communication network. One such method comprises assigning geographic location coordinates to a device of the IP communication network. The geographic location coordinates of the device identify the approximate geographic location of the device. This exemplary method also involves determining an IP address for the device, the IP address comprising (a) a subnet prefix and (b) a portion comprising an identifier indicative of the geographic location of the device. Such an IP address may also comprise additional information including, for example, information useful in distinguishing amongst devices located at the same location.
Certain embodiments of the present invention relate to systems and methods for routing packets of data. One method for facilitating the routing of a data packet comprises addressing a packet to a destination device of a plurality of devices by including an IP address of the destination device in the packet, the IP address of the destination device comprising (a) a subnet prefix and (b) a portion comprising an identifier indicative of the geographic location of the device. The geographic location of the destination device identifies the approximate geographic location of the destination device. The method may further comprise routing the packet from a source device to the destination device using the identifier indicative of the geographic location of the destination device.
Certain embodiments of the present invention provide interoperable networks that allow geographic based packet routing. One such system comprises a first subnet of IP compatible nodes and a second subnet of IP compatible nodes. One or more of these node devices are assigned an IP address comprising (a) a subnet prefix identifying its respective subnet and (b) a portion comprising an identifier indicative of its geographic location. One or more router nodes may be capable of using the geographic location of an IP address of a packet to route the packet, for example to select to which subsequent node to send the packet.
These embodiments are mentioned to provide examples and aid understanding. Additional embodiments and advantages are also discussed in the Detailed Description and will become readily apparent to those skilled in the art. As will be realized, the invention is capable of other and different embodiments, and its several details are not essential, but rather are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
The above described and other features, aspects, and advantages of the present disclosure are better understood when the following Detailed Description is read with reference to the accompanying drawings, wherein:
An exemplary embodiment of the present disclosure extends existing geographic routing mechanisms into the standard, interoperable Internet Protocol (IP). IP is a data-oriented, network layer protocol generally used for communicating data across a packet-switched inter-network. IP version 4 (IPv4) addresses are usually represented in dotted-decimal notation (four numbers, each ranging from 0 to 255). IP version 6 (IPv6) addresses are 128 bits and consists of eight, 16-bit fields, with each field containing a hexadecimal number bounded by a colon. IPv6 addresses are well suited for use in certain embodiments of the present invention and thus used in the following exemplary embodiments.
Specifically, the network 1 comprises a first internal network of routers 20, 30, and 40 connected by links 24, 34 and a second internal network of routers 60, 70, 80 connected by links 64, 74. Each link is populated by hosts and terminated by a router. Each boundary router 20, 60 runs a tunnel (providing a virtual path) 15, 55 to an ISP 10, 50, which provides Internet connectivity for the network 1.
A subnet is any administrative segment of an IP network. As examples, host node 26 is administered by subnet 25 and host nodes 36, 37 are administered by subnet 35. However, multilink subnets may be used, where nodes on more than one link can be components of a single subnet. For example host nodes 66, 67 on link 64 and host nodes 68, 69 on link 74 are administered as a single subnet 65. Nodes on a link can also be administered in separate subnets.
According to RFC 4291, “IP Version 6 Addressing Architecture,” some portion of an IPv6 address is reserved for “interface ID.” For example,
Certain embodiments of the present invention encode or otherwise embed geographic routing information into IP addresses, for example, by including such information in the interface ID portion 206 of an IP address 200. IPv6 nodes may have differing knowledge of the internal structure of the IP address, depending on the node's role, e.g., host versus router. As described in RFC 4291, a host may be aware of subnet prefix(es) for the link(s) it is attached to, where different addresses may have different values for n: subnet prefix (n bits); interface ID (128−n bits). Routers will generally have knowledge of one or more of the hierarchical boundaries for the operation of routing protocols. The known boundaries may differ from router to router depending on what position the router holds in a routing hierarchy. Also according to RFC 4291, except for knowledge about the subnet boundary, nodes will not make assumptions about the structure of an IPv6 address. According to RFC 4291, Interface IDs in IPv6 addresses are used to identify interfaces on a link. They are required to be unique within a subnet prefix and may be unique over a broader scope. In some cases, an Interface ID will be derived from that interface's link layer address. IPv6 interface ID field can include Ethernet layer address info, but under usual use of Ethernet layer that would not include geographic data.
Certain embodiments of the present invention utilize the capacity of the IPv6 addressing scheme (and perhaps other interoperable network addressing schemes) that provide sufficient address space and flexibility to include information about geographic routing and facilitate the routing of IP data with little or no routing overhead (i.e., one does not have to specify a complete path or involve the exchange of routing tables or routing packets) and thus little or no additional datagram bytes need be consumed.
For example, a geographic location may be entered or assigned at the time a node (or related) device is deployed, e.g., a handheld device or head end device could get the present street address and convert to latitude, longitude, altitude or any other useful geographic positioning information. This geographic information may then be associated with the node device and incorporated into the IPv6 interface ID created for that device. Obviously, various types of information can be used to assist with geographic routing, and thus such information is not limited to coordinate, direction, relative location, or any other specific type of such information, so long as such information can be used to route or assist with routing based on the node's geographic location. The geographic information may provide different levels of accuracy in differing dimensions and/or be used by routing algorithms that weight one geographic feature more than another in geographic-based routing decisions, e.g., by weighting latitude as more important than longitude. The geographic information may be encoded in one or more subsets of bits. A single subset of bits may represent a certain dimension, while another subset of bits represents another dimension. A single set of bits may encode multi-dimensional geographic information. Generally, the geographic information may be included, encoded, identified, referenced, or otherwise incorporated in an interface ID in a variety of alternative ways.
The method 300 also comprises determining an IP address for the device, as shown in block 320. The IP address comprising (a) a subnet prefix and (b) a portion comprising an identifier indicative of the geographic location of the device. It may comprise additional information as well. The subnet prefix may be used to allow routing to one or more subnets of the IP communication network.
The method 400 may further comprise routing the packet from a source device to the destination device using the identifier indicative of the geographic location of destination device, as shown in block 420. As previously described, such routing may employ a variety of suitable techniques, including but limited to, routing the packet via a series of intermediates using the geographic coordinates of the destination, where each intermediate node selects a successor node by determining, among potentially other things, the maximum forward geographic progress attainable by candidate successor nodes.
In certain embodiments, methods and systems address the situation in which a packet comprising an IP address with a geographic location identifier is routed on a network that does not use geographic routing. In one exemplary method, a packet destined for a network that does use geographic routing traverses a network that does not. In this exemplary method, the geographic information in the IP address need not affect the normal behavior of the network being traversed.
The foregoing description of the embodiments of the invention has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. The techniques of the invention are not limited to particular systems, networks, or any other particular network configuration or protocol. Thus, in general, numerous modifications and adaptations are apparent to those skilled in the art without departing from the spirit and scope of the invention. For example, while
