METHODS AND APPARATUS FOR BROADCAST OPTIMIZATION IN MOBILE IP

• US 20120281612A1
• Filed: 07/13/2012
• Published: 11/08/2012
• Est. Priority Date: 09/25/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Patel, Alpesh, Leung, Kent K.
• Granted Patent: US 8,755,354 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/14 Backbone network devices

Abstract

In accordance with various embodiments, a Home Agent receives a registration request and sends a registration reply having a network mask extension including a network mask associated with the home address of the Mobile Node. Once the Mobile Node has obtained its network mask, it may send packets such as broadcast packets, as well as roam to its Home Agent. Additionally, in accordance with various embodiments, when a Home Agent receives a broadcast packet, it forwards the broadcast packet to a care-of address of the broadcast packet without duplicating the broadcast packet. Instead, the Foreign Agent obtains the subnet from the broadcast packet, identifies the Mobile Node(s) on that subnet, and duplicates the broadcast packet for transmission to the identified Mobile Node(s).

Claims

1. A Foreign Agent supporting Mobile IP, comprising:

a processor; and

a memory, at least one of the processor or the memory being adapted for;

receiving a broadcast data packet addressed to a subnet;

obtaining the subnet from the broadcast data packet;

identifying two or more Mobile Nodes on the obtained subnet from a table; and

duplicating the broadcast data packet and transmitting each duplicate broadcast data packet to a different one of the two or more Mobile Nodes.

2. The Foreign Agent as recited in claim 1, at least one of the processor or the memory being adapted for performing steps, further comprising:

receiving a packet from a Home Agent, the packet including a network mask associated with a Mobile Node;

obtaining the network mask associated with the Mobile Node from the packet, the network mask enabling a subnet of the Mobile Node to be determined;

updating a table entry in the table with information indicating the subnet of the Mobile Node.

3. In a Foreign Agent supporting Mobile IP, a method, comprising:

receiving a broadcast data packet addressed to a subnet;

obtaining the subnet from the broadcast data packet;

identifying two or more Mobile Nodes on the obtained subnet from a table; and

duplicating the broadcast data packet and transmitting each duplicate broadcast data packet to a different one of the two or more Mobile Nodes.

4. The method as recited in claim 3, further comprising:

receiving a packet from a Home Agent, the packet including a network mask associated with a Mobile Node;

obtaining the network mask associated with the Mobile Node from the packet, the network mask enabling a subnet of the Mobile Node to be determined; and

updating a table entry in the table with information indicating the subnet of the Mobile Node.

5. The method as recited in claim 4, wherein the packet comprises a registration reply.

6. The method as recited in claim 4, wherein the packet comprises a network mask extension including the network mask associated with the Mobile Node;

wherein obtaining the network mask comprises obtaining the network mask associated with the Mobile Node from the network mask extension of the packet.

7. The method as recited in claim 4, further comprising:

determining the subnet of the Mobile Node from a home address of the mobile node using the network mask.

8. The method as recited in claim 3, wherein the broadcast data packet is a subnet directed broadcast data packet.

9. The method as recited in claim 8, wherein duplicating the broadcast data packet and transmitting the duplicated broadcast data packet to the two or more Mobile Nodes comprises:

modifying a destination IP address of the broadcast data packet from a subnet directed broadcast address to a link local broadcast address or a unicast address.

10. The method as recited in claim 8, wherein duplicating the broadcast data packet and transmitting the duplicated broadcast data packet to the two or more Mobile Nodes comprises:

transmitting the subnet directed broadcast data packet to the two or more Mobile Nodes.

11. The method as recited in claim 3, wherein the table is a visitor table, wherein identifying two or more Mobile Nodes on the obtained subnet from the table comprises:

obtaining a network mask from one of a plurality of entries in the visitor table;

obtaining a home address from the one of the plurality of entries in the visitor table;

identifying a subnet from the network mask and the home address; and

determining whether the subnet is identical to the obtained subnet.

12. The method as recited in claim 4, wherein the information indicating the subnet of the Mobile node comprises the network mask.

13. The method as recited in claim 3, wherein the destination IP address of the received broadcast data packet is a link local broadcast address, the method further comprising:

modifying the destination IP address to a subnet-directed broadcast address prior to forwarding the broadcast data packet via the care-of address.

14. In a Home Agent supporting Mobile IP, a method of processing a registration request, comprising:

receiving a registration request, the registration request identifying a Mobile Node and a care-of address of the Mobile Node;

updating a mobility binding table with the care-of address of the Mobile Node;

composing and sending a registration reply to the care-of address of the Mobile Node;

receiving a broadcast data packet; and

forwarding the broadcast data packet via the care-of address without duplicating the broadcast data packet.

15. The method as recited in claim 14, wherein forwarding the broadcast data packet via the care-of address is performed without encapsulating the broadcast data packet when the care-of address is a collocated care-of address.

16. The method as recited in claim 14, wherein the destination IP address of the broadcast data packet is a link local broadcast address or a subnet-directed broadcast address.

17. A Home Agent supporting Mobile IP and adapted for processing a registration request, comprising:

a processor; and

a memory, at least one of the processor or the memory being adapted for;

receiving a registration request, the registration request identifying a Mobile Node and a care-of address of the Mobile Node;

updating a mobility binding table with the care-of address of the Mobile Node;

composing and sending a registration reply to the care-of address of the Mobile Node;

receiving a broadcast data packet; and

forwarding the broadcast data packet via the care-of address without duplicating the broadcast data packet.

18. The Home Agent as recited in claim 17, wherein forwarding the broadcast data packet via the care-of address is performed without encapsulating the broadcast data packet when the care-of address is a collocated care-of address.

19. The Home Agent as recited in claim 17, wherein the destination IP address of the broadcast data packet is a link local broadcast address or a subnet-directed broadcast address.

20. The Home Agent as recited in claim 17, the registration reply having a network mask extension including a network mask associated with the home address of the Mobile Node.

21. A Foreign Agent supporting Mobile IP, comprising:

means for receiving a broadcast data packet addressed to a subnet;

means for obtaining the subnet from the broadcast data packet;

means for identifying two or more Mobile Nodes on the obtained subnet from a table; and

means for duplicating the broadcast data packet and transmitting each duplicate broadcast data packet to a different one of the two or more Mobile Nodes.