Title of Invention

METHOD FOR OPTIMIZING ROUTE WHEN A DUAL MOBILE IPv4 NODE IS CONNECTED TO AN IPv6-ONLY NETWORK

Abstract

The invention generally deals with wireless communication technology and particularly to a method for achieving route optimization when dual capable MIPv4 mobile node is connected with V6 only network wherein the 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. This invention explains a method for route optimization with dual MIPv4 node in IPv6-only network comprising the steps of: getting configured with visited IPv6 address from a router when Dual capable MN is connected to IPv6 only network; updating HA with V6 address; deregistering BU with CN Via HA; updating CN with V6 address; checking reachability of CN through its V6 address; MN starts sending data packets to CN tunneled in V6 packet once the reachability is verified; and CN sending data packets tunneled directly to MN's V6 address.

Full Text

FIELD OF THE INVENTION The invention generally deals with wireless communication technology and particularly to a method for achieving route optimization when dual capable MIPv4 mobile node is connected with V6 only network wherein the 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. DESCRIPTION OF RELATED ART An IP address is used to identify both node and its location inside an IP network. It is obvious that whenever a mobile node moves inside the network, its IP address must also change. Many approaches have been proposed to support mobility in IP networks, sometimes designed to solve only specific problems. Handover latency, signaling and packet loss are the major issues need to be addressed. Using the existing technology route optimization is not available and the 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 IPv6-only network. The various steps undergone in the existing technology can be stated as follows: i) When a MIPv4 capable dual node enters an IPv6 only network, the node obtains an IPv6 Address. ii) On receiving RA, MN realizes it is IPv6 only network. It sends a Binding Update containing the IPv6 address of the node to its Home Agent. iii) On receiving the IPv6 address of MN, a bidirectional tunnel is established between the HA and the node in IPv6 only network. iv) All packets to and from the node goes via the established bidirectional tunnel. Since all the packets that pass to and from MN, traverses via bidirectional tunnel between HA and MN, HA is overheaded. If the Home Agent does not support IPv4-over-IPv6 tunneling, the mobile host cannot communicate with any CN. One of the patent publications describes the route optimization of a dual stack MIPv4 node in an IPv6- only network. The MN registers its new CoA with the Home agent (HA). The MN performs route optimization by sending BU message to CN via edge router, wherein IPv4 data is encapsulated in IPv6 packet. The edge router decapsulates the tunneled packet and forwards the data packet to CN. Once the CoA of other nodes is known, they establish direct communication between them without the need of HA. Another patent publication describes a technique of MN registering with its HA after moving into a foreign network. The CN sends a data packet incorporating its CoA to the MN via HA. The HA intercepts packets directed to MN from CN, and, retransmits the decapsulated packet to the MN. The MN extracts CoA and sends a direct registration request to CN. The CN extracts CoA of MN and establishes direct transmission of packets to the MN. However, this patent publication does not explicitly describe the roaming MN as an MIPv4 dual node in an IPv6 only network. Yet another patent publication describes direct transmission of messages between MN and CN employing care-of address. The CN initiates the process by sending its CoA in a tunneled packet to the MN via HA. The HA decapsulates the packet and retransmits the CoA of CN to MN. The MN replaces its destination address with the received CoA of CN and sends a direct binding update message incorporating its unique CoA as source address to the CN. Once, both the nodes exchange their CoA address, a direct communication between them is established. However, in the current invention, MN initiates the process by transmitting a tunneled packet to the CN. Moreover, the testing message is sent prior to the data packets to confirm their reachability. SUMMARY OF THE INVENTION The objective of the proposed invention is to achieve direct packet delivery (Route Optimization) between MN and CN avoiding bidirectional tunnel path via Home Agent, when dual capable MIPv4 node moves to IPv6-only network. RO is achieved by making use of IPv6 capability of CN or router that is on link with CN (which can act on behalf of CN) by forming V6 tunneling. IPv4 packets originating from MN are encapsulated/tunneled inside IPv6 header and decapsulated by CN/Router (on behalf of CN) on reception. It is assumed 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 IPv4-over-IPv6 tunnel is present within the Home Administrative Domain of the Home Network. In addition MN is expected to have IPv6 address of Home Agent. Accordingly this invention explains a method for route optimization with dual MIPv4 node in IPv6-only network comprising the steps of: (a) getting configured with visited IPv6 address from a router when Dual capable MN is connected to IPv6 only network; (b) updating HA with V6 address; (c) deregistering BU with CN Via HA; (d) updating CN with V6 address; (e) checking reachability of CN through its V6 address; (f) MN starts sending data packets to CN tunneled in V6 packet once the reachability is verified; and (g) CN sending data packets tunneled directly to MN's V6 address. Updating HA with V6 address involves MN sending a BU packet to HA, encapsulated in V6 header. The said packet details involves outer source having MN's Global visited V6 addr, Outer destination having HA's V6 addr and the inner Packet being a normal BU packet. On receiving the packet, HA removes binding cache if any existing for this MN and stores the required tunneling parameters which is , MN's IPv6 address . HA tunnels the packets to and from CN to MN in V6 packet and MN tunnels all the packets destined to CN using HA's V6 address. Deregistering BU with CN Via HA involves MN deregistering its previous binding update with CN, by sending a normal BU packet to CN encapsulated in V6 packet via HA. The said packet details involves outer source having MN's visited v6 global address, outer destination having HA's V6 address , inner source having MN's V4 HoA and inner destination having CN's V4 address and BU. On receiving the said packet, CN removes its binding cache for the said MN and start communicating with MN using its HoA. Udating CN with V6 address involves MN sending a packet to CN via HA, including its V6 address and asking for CN's v6 address. CN stores MN's V6 address to be used for data packet tunneling. CN replies back with its V6 address or router address which is dual and on link with CN. Checking reachability of CN through its V6 address involves MN sending a direct v4-in-v6 packet destined to CN. On receiving the said packet, CN sends response packet directly toMN. These and other objects, features and advantages of the present invention will become more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS Figure 1 shows packet exchanges between MN and HA and between MN and CN via HA, when MN moves to IPv6-only network. Figure 2 shows a new message exchanges between MN and CN via HA to achieve Route Optimization. Figure 3 shows message sequence flow between MN, HA and CN. Figure 4 shows sample formats of new messages introduced by this invention, when MN moves to IPv6-only network. 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. A mobile IPv4 only node can use Mobile IPv4 [MIPv4] to maintain connectivity while moving between IPv4 subnets. Similarly, a mobile IPv6 only node can use Mobile IPv6 [MIPv6] to maintain connectivity while moving between IPv6 subnets. One of the ways of migrating to IPv6 is to deploy dual stack node running both IPv4 and IPv6. Such a node will be able to get both IPv4 and IPv6 addresses and thus can communicate with the current IPv4 Internet as well as any IPv6 nodes and networks as they become available. A dual stack node can use Mobile IPv4 for its IPv4 stack and Mobile IPv6 for its IPv6 stack so that it can move between IPv4 and IPv6 subnets. The present invention relates a method for achieving route optimization when dual capable MIPv4 mobile node is connected with V6 only network where the 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. The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. The following description and drawings are illustrative of the invention and are not to be construed as limiting the innovation. Numerous specific details are described to provide a through understanding of the present 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 IPv6-only network. The Figure depicts handover of a dual capable node from IPv4 network to IPv6 only network. Figure 2 shows a new message exchanges between MN and CN via HA to achieve Route Optimization. IPv6 address is exchanged between CN and MN using bidirectional tunnel via HA and Reachability test messages and further data packets are sent directly using v4-in-v6 tunnel. Once MN gets attached to v6 only network, it gets new v4 address. Then MN updates its HA with new IPv6 address. Thus HA makes a binding entry for this MN with v6 address and here onwards, HA tunnels the packets received for MN's home address to its new v6 address. MN updates CN, via HA about its new V6 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 V6 address and asking CN's v6 address (if its dual), via HA. Packet is v4inv6 tunnel packet. HA detunnels and forwards inner packet to CN. Then CN replies back with v6 address (if its capable) to MN's home address, which is tunneled by HA to MN's new V6 address. Once MN knows CN's V6 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 V4-in-V6 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. It shows the message flow after MN gets attached to foreign network and got new IPv6 address. Lines covered with green box denote V4-in-V6 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 V6 address and asking CN to give its V6 address. Next 2 packet exchanges are to test reachability of CN's V6 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 IPv6-only network. This shows sample implementation of the idea using new Mobility header option. New option is Type-Length-value option carrying, V6 address to and from MN and CN. First 2 packets formats, denotes New mobility header for informing MN's V6 address to CN and getting back reply from CN with its V6 address. Next 2 packets formats, denotes New mobility header for testing reachability of V6 address of CN. 4 new mobility header options are defined. 2 for exchanging IPv6 address from MN to CN and CN to MN, 2 more for Reachability test of v6 address from MN to CN and CN to MN. When MN gets attached with V6-only network, all the traffic to and from MN should traverse via Bidirectional tunnel to HA. Thus adding overload to the Home Agent. This invention allows packets to and from MN to go directly to CN using V4-in-V6 tunnel and to achieve this, MN must be Dual capable. The method of this invention transverse through the following steps: 1. When Dual capable MN is connected to IPv6 only network, it gets configured with visited IPv6 address (global) from the router it is connected with. 2. Updating HA with V6 address: i) MN sends a BU to HA, encapsulated in V6 header. ii) Packet details (Outer source - MN's Global visited V6 addr, Outer destination - HA's V6 addr. Inner Packet is normal BU packet.) iii) On Receiving this packet, HA removes binding cache (if any) existing for this MN and stores the required tunneling parameters ( i. e., MN's IPv6 address ) iv) Now, HA tunnels the packets to and from CN to MN in V6 packet and MN tunnels all the packets destined to CN using HA's V6 address. 3. Deregistering BU with CN ( Via HA): i) MN should deregister its previous binding update with CN, by sending a normal BU to CN encapsulated in V6 packet (via HA) ii) Packet details (Outer source - MN's visited v6 addr ( global), Outer destination - HA's V6 addr, Inner source - MN's V4 HoA, Inner destination - CN's V4 addr and BU) iii) On receiving this packet, CN removes its binding cache for this MN and start communicating with MN using its HoA. 4. Updating CN with V6 address i) MN sends a packet to CN via HA, including its V6 address and asking for CN's v6 address. ii) CN stores MN's V6 address to be used for data packet tunneling. iii) CN replies back with its V6 address (if it is dual capable) or router addr which is dual and on link with CN. 5. Checking reachability of CN through its V6 address ( COTI-COT like): i) MN sends a direct v4-in-v6 packet destined to CN. ii) On receiving this packet, CN sends response packet directly to MN. 6. Ipv4 data packets i) Once the reachability is verified, MN starts sending data packets to CN tunneled in V6 packet. ii) Similarly CN sends data packets tunneled directly to MN's V6 address. It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a microchip, microprocessor, handheld communication device, computer, rendering device or a multi function device. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom. GLOSSARY OF 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 MIPv4: Mobile IPv4 RO: Route Optimization BU: Binding Update CoTI: Care-ofTestlnit CoT: Care-of Test REFERENCES [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. [MIPv4] "IP Mobility", RFC 3344, Aug 2002. WE CLAIM 1. A method for route optimization with dual MIPv4 node in IPv6-only network comprising the steps of: (a) getting configured with visited IPv6 address from a router when Dual capable MN is connected to IPv6 only network; (b) updating HA with V6 address; (c) deregistering BU with CN Via HA; (d) updating CN with V6 address; (e) checking reachability of CN through its V6 address; (f) MN starts sending data packets to CN tunneled in V6 packet once the reachability is verified; and (g) CN sending data packets tunneled directly to MN's V6 address. 2. A method as claimed in claim 1 wherein updating HA with V6 address involves MN sending a BU packet to HA, encapsulated in V6 header. 3. A method as claimed in claim 2 wherein the said packet details involves outer source having MN's Global visited V6 addr, Outer destination having HA's V6 addr and the inner Packet being a normal BU packet. 4. A method as claimed in claim 3 wherein on receiving the packet, HA removes binding cache if any existing for this MN and stores the required tunneling parameters which is, MN's IPv6 address. 5. A method as claimed in claim 4 wherein, HA tunnels the packets to and from CN to MN in V6 packet and MN tunnels all the packets destined to CN using HA's V6 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 packet to CN encapsulated in V6 packet via HA. 7. A method as claimed in claim 6 wherein the said packet details involves outer source having MN's visited v6 global address, outer destination having HA's V6 address, inner source having MN's V4 HoA and inner destination having CN's V4 address and BU. 8. A method as claimed in claim 7 wherein on receiving the said packet, CN removes its binding cache for the said MN and start communicating with MN using its HoA. 9. A method as claimed in claim 1 wherein updating CN with V6 address involves MN sending a packet to CN via HA, including its V6 address and asking for CN's v6 address. 10. A method as claimed in claim 9 wherein CN stores MN's V6 address to be used for data packet tunneling. 11. A method as claimed in claim 10 wherein CN replies back with its V6 address or router address which is dual and on link with CN. 12. A method as claimed in claim 1 wherein checking reachability of CN through its V6 address involves MN sending a direct v4-in-v6 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 for route optimization with dual MIPv4 node in lPv6-only network substantially described particularly with reference to the accompanying drawings.

Documents:

1956-CHE-2005 AMENDED PAGES OF SPECIFICATION 08-05-2013.pdf

1956-CHE-2005 AMENDED CLAIMS 05-08-2013.pdf

1956-CHE-2005 AMENDED CLAIMS 08-05-2013.pdf

1956-CHE-2005 EXAMINATION REPORT REPLY RECEIVED 08-05-2013.pdf

1956-CHE-2005 EXAMINATION REPORT REPLY RECEIVED 05-08-2013.pdf

1956-CHE-2005 FORM-1 05-08-2013.pdf

1956-CHE-2005 FORM-1 08-05-2013.pdf

1956-CHE-2005 FORM-13 08-05-2013.pdf

1956-CHE-2005 FORM-3 08-05-2013.pdf

1956-CHE-2005 FORM-5 08-05-2013.pdf

1956-CHE-2005 OTHER PATENT DOCUMENT 08-05-2013.pdf

1956-CHE-2005 OTHER PATENT DOCUMENT 1 08-05-2013.pdf

1956-CHE-2005 OTHERS 05-08-2013.pdf

1956-CHE-2005 POWER OF ATTORNEY 05-08-2013.pdf

1956-CHE-2005 POWER OF ATTORNEY 08-05-2013.pdf

1956-CHE-2005 FORM-13 19-06-2006.pdf

1956-che-2005-abstract.pdf

1956-che-2005-claims.pdf

1956-che-2005-correspondnece-others.pdf

1956-che-2005-description(complete).pdf

1956-che-2005-drawings.pdf

1956-che-2005-form 1.pdf

1956-che-2005-form 13.pdf

1956-che-2005-form 26.pdf