Non-broadcast multiple access inverse next hop resolution protocol (INHRP)
The present invention is a method and apparatus for obtaining information transmitted between a source station and a destination station in a non broadcast multiple access network. A connection between the source station and a server for the destination station is established. The server has a cache containing the information. The source station transmits a request packet having parameters relating to the information to the server. The source station receives a reply packet containing the information from the server. The reply packet matches the parameters of the request packet.
1. A method of providing, to a source station in a first IP sub-network of a non-broadcast multiple access (NBMA) network, an internetwork layer address for a destination station in a second IP sub-network of the IP sub-network of the NBMA network using an inverse next hop resolution protocol, the method comprising:
sending, from the source station to a server of the first IP sub-network, a resolution request identifying an NBMA network address of the destination station;
receiving the resolution request at the server of the first IP sub-network;
determining an internetwork layer address corresponding to the NBMA network address of the destination station at the server of the first IP sub-network;
sending from the server of the first IP sub-network to the source station, a resolution response indicating the internetwork layer address corresponding to the NBMA network address of the destination station; and
receiving the resolution response at the source station.
2. The method of claim 1 , further comprising caching at the source station information mapping the NBMA network address of the destination station to the internetwork layer address corresponding to the NBMA network address of the destination station.
3. The method of claim 1 , further comprising using the internetwork layer address corresponding to the NBMA network address of the destination station to send packets from the source station to the destination station.
4. The method of claim 1 , wherein determining an internetwork layer address corresponding to the NBMA network address of the destination station comprises determining the internetwork layer address based on information mapping the NBMA network address of the destination station to the internetwork layer address, the information being cached at the server of the first IP sub-network.
5. The method of claim 1 , wherein determining an internetwork layer address corresponding to the NBMA network address of the destination station comprises:
sending a resolution request from the server of the first IP sub-network to at least one server of at least one other IP sub-network;
receiving the resolution request at a server of the second IP sub-network, the server of the second IP sub-network having information mapping the NBMA network address of the destination station to an internetwork layer address associated with the destination station;
sending a resolution response from the server of the second IP sub-network to the server of the first IP sub-network, the resolution response comprising information mapping the NBMA network address of the destination station to the internetwork layer address associated with the destination station; and
receiving the resolution response at the server of the first IP sub-network.
6. The method of claim 5 , further comprising caching, at the server of the first IP sub-network, the information mapping the NBMA network address of the destination station to the internetwork layer address associated with the destination station.
7. The method of claim 5 , further comprising:
sending a registration request from the destination station to the server of the second IP sub-network; and
caching the information mapping the NBMA network address of the destination station to the internetwork layer address associated with the destination station at the server of the second IP sub-network responsive to the registration request.
8. The method of claim 7 , wherein the destination station sends the registration request upon joining the second IP sub-network.
9. The method of claim 7 , wherein the registration request includes the NBMA network address of the destination station.
10. The method of claim 7 , wherein the server of the second IP sub-network sends a registration response to the destination station confirming registration of the destination station at the server of the second IP sub-network.
11. The method of claim 1 , wherein sending the resolution request from the source station to the server of the first IP sub-network comprises sending the resolution request via at least one client router of the first IP-subnetwork.
12. The method of claim 11 , wherein sending the resolution response from the server of the first IP sub-network to the source station comprises sending the resolution response via the at least one client router of the first IP sub-network.
13. The method of claim 1 , wherein sending the registration request from the destination station to server of second IP sub-network comprises sending the registration request via at least one client router of second IP sub-network.
14. The method of claim 3 , wherein using the internetwork layer address corresponding to the NBMA network address of the destination station to send packets from the source station to the destination station comprises sending the packets via at least one client router of the first IP sub-network.
15. The method of claim 3 , wherein using the internetwork layer address corresponding to the NBMA network address of the destination station to send packets from the source station to the destination station comprises sending the packets via at least one client router of the second IP sub-network.
16. The method of claim 1 , wherein the resolution response comprises at least one instance of resource information.
17. The method of claim 16 , wherein the resource information comprises resource availability and upper layer address information.
18. The method of claim 16 , further comprising caching the resource information at the source station.
19. The method of claim 16 , further comprising caching the resource information at the server of the first IP subnetwork.