Title of Invention

A METHOD OF ROUTE OPTIMIZATION WITH DUAL MIPV6 NODE IN IPV4-ONLY NETWORK

Abstract

This invention related to achieving Route Optimization when dual capable MIPv6 Mobile node is connected with V4 only network. Route optimization allows packets To tranverse a shorter route than the default one thought the home agent using bidirectional tunneling thus leading to better bandwidth utilization. This invention explains a method of route optimization with dual MIPV6 node inIPV4-only network comprising the steps of: updating HA with V4 address and deregistering BU with CN via HA; MN informing its IPV4 addr to CN and getting CN’s IPV4 address in reply Checking reachability of CN in its V4 address using v6-in-v4 tunnel; and sending and receiving Ipv6 data packets to/from CN using v4 tunnel.

Full Text

FIELD OF THE INVENTION This invention is related to Achieving Route Optimization when dual capable MIPv6 mobile node is connected with V4 only network. Route optimization allows packets to traverse a shorter route than the default one through the Home Agent using bidirectional tunneling, thus leading to better bandwidth utilization. More particularly the present invention relates to a method of route optimization with dual mipv6 node in ipv4-only network. DESCRIPTION OF THE RELATED ART Currently the route optimization is not available. Using existing solutions, communication between MN and CN is possible only using bidirectional tunneling via HA. Following subsections describe existing communication path between MN and CN, when MN is connected with IPv4-only network. Referring to Figure 1: • When a MIPv6 capable dual node enters an IPv4 only network, the node obtains an IPv4 Address. • On not receiving any RA, MN realizes it is IPv4 only network. It sends a Binding Update containing the IPv4 address of the node to its Home Agent. • On receiving the IPv4 address of MN, a bidirectional tunnel is established between the HA and the node in IPv4 only network. • All packets to and from the node goes via the established bidirectional tunnel. However there are following limitations to the above : "" 1. All the packets to and from MN, traverses via bidirectional tunnel between HA and MN, thus adding overhead to HA. 2. If the Home Agent does not support IPv6-over-IPv4 tunneling, the mobile host cannot communicate with any CN. SUMMARY OF THE INVENTION When MN gets attached with V 4 only network, all the traffic to and from MN should traverse via Bidirectional tunnel to HA. Thus adding overhead to Home Agent. This invention allows packets to and from MN to go directly to CN using V6-in-V4 tunnel. To achieve this, MN must be Dual capable. The purpose of the invention is to achieve direct packet delivery (Route Optimization) between MN and CN avoiding bidirectional tunnel path via Home Agent, when dual capable MIPv6 node moves to IPv4-only network. RO is achieved by making use of IPv4 capability of CN or router that is on link with CN (which can act on behalf of CN) by forming V4 tunneling. IPv6 packets originating from MN are encapsulated/tunneled inside IPv4 header and decapsulated by CN/Router (on behalf of CN) on reception. We assume that MN, CN and HA are dual capable. Instead of CN any dual router connected with CN can act on behalf of CN. Similarly instead of HA any dual router supporting IPv6-over-IPv4 tunnel is present within the Home Administrative Domain of the Home Network. In addition MN is expected to have IPv4 address of Home Agent. Accordingly this invention explains a method of route optimization with dual MIPV6 node in IPV4-only network comprising the steps of: (a) updating HA with V4 address and deregistering BU with CN Via HA; (b) MN informing its IPv4 addr to CN and getting CN's IPv4 address in reply; (c) checking reachability of CN in its V4 address using v6-in-v4 tunnel; and ^ (d) sending and receiving Ipv6 data packets to/from CN using v4 tunnel. Updating HA with V4 address involves MN sending a BU packet to HA, encapsulated in V4 header. The said packet has outer source as MN's global visited V4 addr and outer destination as HA's V4 addr where the inner packet is a normal BU packet. On receiving the said packet, HA removes binding cache if any existing for the said MN and stores the required tunneling parameters. HA tunnels the packets to and from CN to MN in V4 packet and MN tunnels all the packets destined to CN using HA's V4 address. Deregistering BU with CN Via HA involves MN deregistering its previous binding update with CN, by sending a normal BU to CN encapsulated in V4 packet via HA. The said packet has outer source as MN's visited v4 global addr, outer destination as HA's V4 addr, inner source as MN's V6 HoA and inner destination as CN's V6 addr and BU. The said packet, CN removes its binding cache for this MN and start communicating with MN using its HoA. Informing CN with V4 address involves MN sending a packet to CN via HA, including its V4 address and asking for CN's v4 address. CN stores MN's V4 address to be used for data packet tunneling. CN replies back with its V4 address if it is dual capable or router addr which is dual and on link with CN. Checking reachability of CN through its V4 address involves MN sending a direct v6-in-v4 packet destined to CN. On receiving the said packet, CN sends response packet directly to MN. Sending and receiving Ipv6 data packets to/from CN using v4 tunnel involves MN starts sending data packets to CN tunneled in V4 packet once the reachability is verified. In return CN sends data packets tunneled directly to MN's V4 address. These and other objects, features and advantages of the present invention will become more readily apparent from the detailed description taken in conjunction with the drawings and the claims. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS ^ Figure 1 shows an existing communication path between MN and CN when MN attached with IPv4 only network. Figure 2 illustrates a new messages via HA and then direct delivery of data packets. Figure 3 illustrates the present invention operation sequence when attached to IPv4-only network. Figure 4 shows a sample packet format of NEW messages using new Mobility Header types. DETAILED DESCRIPTION OF THE INVENTION The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail. Figure 1 shows packet exchanges between MN and HA and between MN and CN via HA, when MN moves to IPv4-only network. The Figure depicts handover of a dual capable node from IPv6 network to IPv4 only network. Figure 2 shows a new message exchanges between MN and CN via HA to achieve Route Optimization. IPv4 address is exchanged between CN and MN using bidirectional tunnel via HA and Reachability test messages and further data packets are sent directly using v6-in-v4 tunnel. Once MN gets attached to v4 only network, it gets new v4 address. Then MN updates its HA with new IPv4 address. Thus HA makes a binding entry for this MN with v4 address and here onwards, HA tunnels the packets received for MN's home address to its new v4 addr.MN updates CN, via HA about its new V4 address. Thus CN updates its binding entry. This communication is shown using PIPE and lines colored RED. After updating HA, MN sends out a new message to CN giving its V4 address and asking CN's v4 address ( if its dual), via HA. Packet is v6inv4 tunnel packet. HA detunnels and forwards inner packet to CN. Then CN replies back with v4 address (if its capable) to MN's home address, which is tunneled by HA to MN's new V4 address. Once MN knows CN's V4 address, it does address reachability test for direct delivery.After getting reply from CN for both, MN starts sending data packets directly to CN using V6-in-V4 tunnels.This communication is shown using PIPE and lines colored BLUE.Finally, Data packet communication is shown with direct BLUE lines from MN and CN. Figure 3 shows message sequence flow between MN, HA and CN. It depicts tunneled and decapsulated packets in differentiate manner.lt shows the message flow after MN gets attached to foreign network and got new IPv4 address.Lines covered with green box denote V6-in-V4 tunnel packets. Direct lines show packets that are not tunneled, mainly plain packets between CN and HA.First 2 packet exchanges are to update HA with MN's move. Next 2 packet exchanges are to update CN with MN's move. Via HA. Next 2 packet exchanges are informing MN's V4 address and asking CN to give its V4 address.Next 2 packet exchanges are to test reachability of CN's V4 address for direct delivery.Final 2 packet exchanges show how data packets are transmitted between MN and CN. Figure 4 shows sample formats of new messages introduced by this invention, when MN moves to IPv4-only network. This shows sample implementation of the idea using new Mobility header option. New option is Type-Length-value option carrying, V4 address to and from MN and CN. First 2 packets formats, denotes new mobility header for informing MN's V4 address to CN and getting back reply from CN with its V4 address. Next 2 packets formats, denotes New mobility header for testing reachability of V4 address of CN. 4 new mobility header options are defined. 2 for exchanging IPv4 address from MN to CN and CN to MN, 2 more for Reachability test of v4 address from MN to CN and CN to MN. Operation of the invention • When Dual capable MN is connected to IPv4 only network, it gets configured with visited IPv4 address (global) from the router it is connected with. • Updating HA with V4 address: o MN sends a BU to HA, encapsulated in V4 header, o Packet details (Outer source - MN's Global visited V4 addr, Outer destination - HA's V4 addr. Inner Packet is normal BU packet.) o On Receiving this packet, HA removes binding cache (if any) existing for this MN and stores the required tunneling parameters (i.e.., MN's IPv4 address) o Now, HA tunnels the packets to and from CN to MN in V4 packet and MN tunnels all the packets destined to CN using HA's V4 address. • Deregistering BU with CN (Via HA): o MN should deregister its previous binding update with CN, by sending a normal BU to CN encapsulated in V4 packet (via HA) o Packet details (Outer source - MN's visited v4 addr ( global), Outer destination - HA's V4 addr, Inner source - MN's V6 HoA, Inner destination - CN's V6 addr and BU) o On receiving this packet, CN removes its binding cache for this MN and start communicating with MN using its HoA. • Updating CN with V4 address ^ o MN sends a packet to CN via HA, including its V4 address and asking for CN's v4 address, o CN stores MN's V4 address to be used for data packet tunneling, o CN replies back with its V4 address (if it is dual capable) or router addr which is dual and on link with CN. • Checking reachability of CN through its V4 address ( COTI-COT like): o MN sends a direct v6-in-v4 packet destined to CN. o On receiving this packet, CN sends response packet directly to MN. • Ipv6 data packets o Once the reachability is verified, MN starts sending data packets to CN tunneled in V4 packet, o Similarly CN sends data packets tunneled directly to MN's V4 address. The above-presented description is of the best mode contemplated for carrying out the present invention. The manner and process of making and using it is in such a full, clear, concise and exact terms as to enable to any person skilled in the art to which it pertains to make and use this invention. New embodiments in particular, which also lie within the scope of the invention can be created, in which different details of the different examples can in a purposeful way be combined with one another. This invention is however, susceptible to modifications and alternate constructions from that disclosed above which are fully equivalent. Consequently, it is not the intention to limit this invention to the particular embodiment disclosed. On the contrary, the intention is to cover all modifications and alternate constructions coming within the spirit and scope of the invention as generally expressed by the following claims which particularly point out and distinctly claim the subject matter of the invention. GLOSSARY OF THE TERMS AND DEFINITIONS THEREOF CoA: Care of Address HoA: Home Address HA: Home Agent CN: Correspondent node MN: Mobile Node RA: Router Advertisement MH: Mobility Header MIPv6: Mobile IPv6 RO: Route Optimization BU: Binding Update CoTI: Care-of Test Init CoT: Care-of Test Reference [IPv4 CoA Registration] Ryuji Wakikawa, Vijay Devarapalli, Carl E. Williams, "IPv4 Care-of Address Registration", draft-wakikawa-nemo-v4tunnel-01 .txt [NEMO] V.Devarapalli, R. Wakikawa, A. Petrescu, P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005. [MIPv6] D. Johnson, C. Perkins and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004. [IPv6] Deering S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. WE CLAIM 1. A method of route optimization with dual MIPV6 node in IPV4-only network comprising the steps of: (a) updating HA with V4 address and deregistering BU with CN Via HA; (b) MN informing its IPv4 address to CN and getting CN's IPv4 address in reply; (c) checking reachability of CN in its V4 address using v6-in-v4 tunnel; and (d) sending and receiving Ipv6 data packets to/from CN using v4 tunnel. 2. A method as claimed in claim 1 wherein updating HA with V4 address involves MN sending a BU packet to HA, encapsulated in V4 header. 3. A method as claimed in claim 2 wherein the said packet has outer source as MN's global visited V4 address and outer destination as HA's V4 address where the inner packet is a normal BU packet. 4. A method as claimed in claim 2 wherein on receiving the said packet, HA removes binding cache if any existing for the said MN and stores the required tunneling parameters. 5. A method as claimed in claim 2 wherein HA tunnels the packets to and from CN to MN in V4 packet and MN tunnels all the packets destined to CN using HA's V4 address. 6. A method as claimed in claim 1 wherein deregistering BU with CN Via HA involves MN deregistering its previous binding update with CN, by sending a normal BU to CN encapsulated in V4 packet via HA. ^ 7. A method as claimed in claim 6 wherein the said packet has outer source as MN's visited v4 global addr, outer destination as HA's V4 addr, inner source as MN's V6 HoA and inner destination as CN's V6 address and BU. 8. A method as claimed in claim 6 wherein on receiving the said packet, CN removes its binding cache for this MN and start communicating with MN using its HoA. 9. A method as claimed in claim 1 wherein informing CN with V4 address involves MN sending a packet to CN via HA, including its V4 address and asking for CN's v4 address. 10. A method as claimed in claim 9 wherein CN stores MN's V4 address to be used for data packet tunneling. 11. A method as claimed in claim 9 wherein CN replies back with its V4 address if it is dual capable or router addr which is dual and on link with CN. 12. A method as claimed in claim 1 wherein checking reachability of CN through its V4 address involves MN sending a direct v6-in-v4 packet destined to CN. 13. A method as claimed in claim 12 wherein on receiving the said packet, CN sends response packet directly to MN. 14. A method as claimed in claim 1 wherein sending and receiving Ipv6 data packets to/from CN using v4 tunnel involves MN starts sending data packets to CN tunneled in V4 packet once the reachability is verified. 15. A method as claimed in claim 14 wherein in return CN sends data packets tunneled directly to MN's V4 address. 16.A method of route optimization with dual MIPV6 node in IPV4-only network substantially described particularly with reference to the accompanying drawings.

Documents:

1552-CHE-2005 AMENDED PAGES OF SPECIFICATION 01-08-2012.pdf

1552-CHE-2005 AMENDED CLAIMS 01-08-2012.pdf

1552-CHE-2005 EXAMINATION REPORT REPLY RECEIVED 01-08-2012.pdf

1552-CHE-2005 FORM-13 19-06-2006.pdf

1552-CHE-2005 FORM-3 01-08-2012.pdf

1552-CHE-2005 FORM-6 01-08-2012.pdf

1552-CHE-2005 OTHER PATENT DOCUMENT 01-08-2012.pdf

1552-CHE-2005 POWER OF ATTORNEY 01-08-2012.pdf

1552-CHE-2005 ABSTRACT.pdf

1552-CHE-2005 CLAIMS.pdf

1552-CHE-2005 CORRESPONDENCE OTHERS.pdf

1552-CHE-2005 DESCRIPTION (COMPLETE).pdf

1552-CHE-2005 DRAWINGS.pdf

1552-CHE-2005 FORM 1.pdf

1552-CHE-2005 FORM 18.pdf

1552-CHE-2005 POWER OF ATTORNEY.pdf