Methods and apparatus for broadcast domain interworking
View Patent ↗A P device interworks CE devices connected to the P device using different types of data links. The P device learns the address of a local CE device by monitoring the control messages, such as address resolution messages, originating from the local device. The P device may share the address of a local CE device with another local CE device by initiating a control message or responding to a control message issued by one of the local CE devices. This latter mechanism in effect hides the heterogeneous nature of the network.
1. In a device bridging data link layer protocols and network layer protocols, a method of resolving network addresses between network devices on a heterogeneous network, the method comprising:
gathering information from a control message concerning a first device in communication with a first data link;
responding to the control message using information gathered by the device, if available;
receiving packets from a second device in communication with a second data link, the first and second data links using different data link layer protocols; and
transmitting the packets to the first device using the gathered information concerning the first device, wherein one of the first and second data links is a bridging data link and the other data link is a point-to-point data link.
2. The method of claim 1 wherein the control message is an address resolution message.
3. The method of claim 1 wherein the gathered information is at least one of the first device's IP address, circuit information, a VC or VPN MPLS label, or the IP address for the second device associated with that label.
4. The method of claim 1 wherein the first data link is a gigabit Ethernet data link.
5. The method of claim 4 wherein the control message is an RDP message.
6. The method of claim 1 wherein the first data link is a frame relay data link.
7. The method of claim 6 wherein the control message is an IARP message.
8. The method of claim 1 wherein the first data link is a PPP data link.
9. The method of claim 8 wherein the control message is an IPCP message.
10. The method of claim 1 wherein the first data link is an ATM data link.
11. The method of claim 10 wherein the control message is an INATMARP message.
12. The method of claim 1 wherein the first data link is an HDLC data link.
13. The method of claim 1 wherein transmitting the packets comprises prepending a header identifying the second device to a received packet.
14. The method of claim 1 further comprising responding to the control message using a placeholder value.
15. A system that resolves network addresses between network devices on a heterogeneous network, the system comprising:
a first device bridging data link layer protocols and network layer protocols;
a second device in communication with the first device using a first data link; and
a third device in communication with the first device using a second data link, the first and second data links using different data link layer protocols,
wherein the first device gathers information concerning the second and third devices from control messages sent by the second and third devices, one of the first and second data links is a bridging data link, and the other data link is a point-to-point data link; and wherein the first device is adapted to respond to the control messages using the information gathered.
16. The system of claim 15 wherein the control messages are address resolution messages.
17. The system of claim 15 wherein the first data link is a gigabit Ethernet data link.
18. The system of claim 15 wherein the first data link is a frame relay data link.
19. The system of claim 15 wherein the first data link is a PPP data link.
20. The system of claim 15 wherein the first data link is an ATM data link.
21. The system of claim 15 wherein the first data link is a HDLC data link.