Network interconnecting apparatus having a separate forwarding engine object at each interface

• US 5,951,649 A
• Filed: 03/08/1996
• Issued: 09/14/1999
• Est. Priority Date: 03/22/1994
• Status: Expired due to Term

• Current Assignee: Enterasys Networks Incorporated (Extreme Networks, Inc.)
• Original Assignee: Cabletron Systems Incorporated (Extreme Networks, Inc.)
• Inventors: Cormier, Len, Haggerty, William, Simoneau, Paul, Dobbins, Kris, Soczewinski, Rich, Dobbins, Kurt, Yohe, Kevin
• Primary Examiner(s): Kim, Kenneth S.
• Application Number:
  US08/611,333
• Time in Patent Office: 1,285 Days
• Field of Search: 370/60, 370/94.1, 370/351, 370/428, 395/700.15, 395/683, 395/200.53, 395/200.68, 395/200.79, 709/238, 709/250
• US Class Current: 709/238
• CPC Class Codes: H04L 12/46 Interconnection of networks
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/0233 Object-oriented techniques, for representation of network management data, e.g. common object request broker architecture [CORBA]
• CPC Class Codes: H04L 41/082 the condition being updates or upgrades of network functionality
• CPC Class Codes: H04L 41/0856 by backing up or archiving configuration information
• CPC Class Codes: H04L 41/28 Restricting access to network management systems or functions, e.g. using authorisation function to access network configuration
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/42 Centralised routing
• CPC Class Codes: H04L 45/44 Distributed routing
• CPC Class Codes: H04L 45/52 Multiprotocol routers
• CPC Class Codes: H04L 45/56 Routing software
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

An interconnecting apparatus includes one or more interfaces. Each interface connects to a network. The interconnecting apparatus interconnects the networks attached to the interfaces. The device utilizes distributed autonomous forwarding engines on each interface in that each interface has a forwarding engine corresponding to it. Each forwarding engine only knows the configuration information and how to receive and transmit packets on the one interface to which it corresponds. Each forwarding engine acts independently to process packets, yet each interacts together to collectively provide packet forwarding which is protocol independent, interface independent, and scalable.

Claims

1. In an interconnecting apparatus having a plurality of interfaces for providing data forwarding services between a plurality of communication networks, wherein each interface is capable of attaching to at least one of the plurality of communication networks, and wherein a forwarding and service engine in a source interface is used to determine a destination interface positioned in a path from a source communication network to a destination communication network, the source interface being operable to forward a plurality of data packets to the destination interface within the interconnecting device, the improvement comprising:

an object-oriented program stored in a memory of the interconnecting apparatus and executed by the interconnect apparatus, wherein data and operations are united into fundamental logical building blocks of classes and objects;

an interface object instantiated for each media device driver at each interface of the interconnecting apparatus, each interface object representing a logical interface and being bound to its associated media device driver each media device driver to operate with a respective communication medium attached to the respective interface of the interconnecting apparatus; and

a plurality of separate forwarding and service engine objects, each instantiated and bound to a respective one of the interface objects, and each being operable to forward the plurality of data packets received at the respective interface of the interconnecting apparatus to the destination interface.

2. The apparatus of claim 1, wherein the interface objects include:

a plurality of base interface objects for the registration and transmittal of network packets; and

a plurality of protocol-specific interface objects derived from the base objects and specific to a particular media device driver.

3. The system of claim 1, wherein the forwarding and service engine objects provide:

a. interface to the network;

b. unique framing of network packets to each subnet;

c. processing packets for each network protocol, including encoding and decoding;

d. forwarding packets, including determination of the next hop;

e. filtering packets, including discarding packets if a service is unavailable or denied;

f. utilizing a data cache of active next hops; and

g. address resolution at the last hop to map a network address to a media address.

4. In a method of providing data forwarding services between a plurality of communication networks including forwarding of a data packet from a source network to a destination network, the improvement comprising:

in an interconnecting apparatus having a plurality of interfaces for providing data forwarding services between the plurality of communication networks, instantiating an interface object for each media device driver on each interface of the interconnecting apparatus, each interface object representing a logical interface and being bound to its associated media device driver, each media device driver to operate with a respective communication medium attached to the respective interface of the interconnecting apparatus;

instantiating and binding a separate forwarding engine object to each separate interface object;

in response to receipt of a data packet on a source interface of the interconnecting apparatus, the interface object for the source interface calling a service method in its bound forwarding engine object;

the service method removing the sublayer framing on the data packet;

the service method performing validation and extraction of the destination address from the data packet;

the service method providing a next hop determination by looking up the destination address in a cache memory of active addresses to determine a destination forwarding engine object handle identifying the engine object to which the data packet is forwarded, and, if the destination address is not located in the cache memory, accessing a forwarding lookup table for the best route to the destination address and updating the cache memory; and

returning the determined destination forwarding engine object handle to the interface object for the source interface.

5. The method of claim 4, further comprising:

upon receipt of the destination forwarding engine object handle,

calling a service method in the destination forwarding engine object,

the service method validating the destination address;

the service method looking up in an address cache to obtain a media specific address of the destination; and

the service method reframing the packet and transferring it to the destination interface.

6. A method of distributed input/output processing by an input/output interface in an interconnecting apparatus having a plurality of input/output interfaces operable between a plurality of communication networks for providing data forwarding services between a plurality of communication networks, the method comprising the steps of:

a) providing a plurality of interface objects, each interface object having only configuration and forwarding information for an associated input/output interface of the interconnecting apparatus, wherein the associated input/output interface is capable of attaching to at least one of the plurality of communication networks and wherein each interface object represents a logical interface which is bound to its associated input/output interface; and

b) upon receipt of an incoming data packet at one interface object, the one interface object accessing its forwarding information to determine a next interface object and forwarding the data packet to the determined next interface object, wherein each interface object acts independently to process the incoming data packet.

7. The method of claim 6, wherein each interface object is a managed object which includes methods and data for network management.

8. The method of claim 6, wherein each interface object is accessible through a base class for instantiation and control.

9. The method of claim 6, wherein the interface objects serve as network access points.

10. The method of claim 6, wherein the configuration information includes media and data packet framing information specific to the associated input/output interface.

11. The method of claim 6, wherein the method enables protocol independent switching of data packets.

12. The method of claim 6, wherein step a) includes the step of delivering packets to a higher layer application.

13. The method of claim 6, wherein step a) includes the step of reframing between different media types provided on different network interfaces.

14. The method of claim 6, wherein step b) includes the step of looking up, by a service method of the interface object, a destination address in a cache memory to determine the next interface object.

15. The method of claim 6, wherein step b) includes the steps of

looking up, by a service method of the interface object, a destination address in a cache memory to determine a media specific address of the destination,

reframing the data packet;

and

transferring the data packet to the next interface object.

16. The method of claim 6, wherein step a) includes the step of deriving interface objects from a common base class.

17. A computer-readable storage medium having computer-readable program code embodied on the computer-readable storage medium, the program code enabling an interconnecting apparatus having a plurality of input/output interfaces operable between a plurality of communication networks to forward data packets between input/output interfaces, the program code including:

a resource object being operable to instantiate a plurality of autonomous interface objects and to bind each interface object to an associated input/output interface; and

each interface object having media and data packet framing information only for the associated input/output interface and its own forwarding information for forwarding an incoming data packet received on the associated input/output interface to a next interface object.