US 5,251,205 A · Multiple protocol routing

Abstract

A method for connecting a network so that TCP/IP and OSI 8473 packets may be routed in the same domain. The independence of the addresses is maintained: one device in the network may be assigned only a TCP/IP address, and another device may be assigned only a ISO 8473 address. Furthermore, all of the routers share link state information by using a common link state packet format (such as the ISO 10589 format); thus routes through the network may be computed without regard for the protocols supported by the routers along the route. Where necessary, packets are encapsulated and forwarded through routers which are not capable in the protocol of the packet. In some disclosed embodiments, all of the routers in a given area support a given protocol (or, in fact, have identical capabilities, in which case encapsulation is not required). In these embodiments, the encapsulation is performed by suitable modifications to each router's packet forwarding procedures. In other disclosed embodiments, these topological restrictions are removed, and the network is expanded to support additional protocols. In these embodiments, the Dijkstra algorithm is also modified to generate information on how to encapsulate and forward packets through the network.

Claims24

Dependent claims

A method of calculating routes for sending user data packets via information handling devices which forward data packets through a communications network, comprising

including in at least a first and a second user data packet, destination address information conforming to two or more different addressing conventions of two or more different independent protocol suites,
determining routes for said first and said second user data packets using a route calculation algorithm corresponding to a single routing protocol, chosen from an arbitrary protocol suite, regardless of the addressing convention to which the destination address information in said user data packet conforms,
said route being determined using the destination address information in said user data packets without converting said destination address information from the addressing convention to which it forms to another addressing convention.

A method for calculating routes for sending user data packets via information handling devices which forward data packets through a communications network, said information handling devices including (a) single-protocol information handling devices capable of recognizing and forwarding only user data packets which conform to a single protocol suite, and (b) multi-protocol information handling devices capable of recognizing and forwarding user data packets which conform to any one of two or more protocol suites, comprising

using a routing protocol to automatically predetermine whether to encapsulate a packet, at which information handling devices to encapsulate and to decapsulate said packet, and which protocol to use to encapsulate said packet, wherein
said network includes (a) single-protocol information handling devices capable of recognizing and forwarding only user data packets which conform to a first protocol suite, (b) single-protocol information handling devices capable of recognizing and forwarding only user data packets which conform to a second different protocol suite, and (c) at least one multi-protocol information handling device capable of recognizing and forwarding user data packets which conform to at least said first and second protocol suites.

A network of information handling devices which forward user data packets through communications links each said packet including an address indicating the packet's destination, said network comprising

a first information handling device capable of interpreting addresses formatted in accordance with a first addressing scheme, said first addressing scheme defining one or more address fields that are assigned values to form an address,
a second information handling device capable of interpreting addresses formatted in accordance with a second addressing scheme, said second addressing scheme defining different address fields than said first addressing scheme, wherein
at least one address formatted in accordance with said first addressing scheme dose not identify the same destination as any address formatted in accordance with said second addressing scheme, and
said first and second devices exchange control packets which specify:
the links connected to the device which originates the control packet,
the addresses, formatted in accordance with said first addressing scheme, of those destinations that are attached to the originating device and have an address corresponding to said first addressing scheme, and
the addresses, formatted in accordance with said second addressing scheme, of those destinations that are attached to the originating device and have an address corresponding to said second addressing scheme.

4 more elements

Dependencies are inferred from the claim text.

Multiple protocol routing

Life of this patent

Multiple protocol routing

Life of this patent

Abstract

Claims24