Unified table for L2, L3, L4, switching and filtering

• US 6,430,188 B1
• Filed: 07/19/2000
• Issued: 08/06/2002
• Est. Priority Date: 07/08/1998
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Kalkunte, Mohan, Ambe, Shekhar, Kadambi, Shiri
• Primary Examiner(s): Hsu, Alpus H.
• Assistant Examiner(s): Tran, Thien
• Application Number:
  US09/619,488
• Time in Patent Office: 748 Days
• Field of Search: 370/395.1, 370/390, 370/391, 370/392, 370/400, 370/401, 370/389, 370/395.2, 370/395.3, 370/395.31, 370/395.32, 370/398, 370/399, 711/202, 711/206, 711/216
• US Class Current: 370/398
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/42 Loop networks
• CPC Class Codes: H04L 12/46 Interconnection of networks
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354
• CPC Class Codes: H04L 12/467 Arrangements for supporting untagged frames, e.g. port-based VLANs
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• 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 45/24 Multipath
• CPC Class Codes: H04L 45/245 Link aggregation, e.g. trunking
• CPC Class Codes: H04L 45/742 Route cache; Operation thereof
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/2458 Modification of priorities while in transit
• CPC Class Codes: H04L 49/205 Quality of Service based
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/3009 : Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/3027 : Output queuing
• CPC Class Codes: H04L 49/3081 : ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04L 49/309 : Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/351 : for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/354 : for supporting virtual local area networks [VLAN]
• CPC Class Codes: H04L 49/602 : Multilayer or multiprotocol switching, e.g. IP switching
• CPC Class Codes: H04L 49/606 : Hybrid ATM switches, e.g. ATM&STM, ATM&Frame Relay or ATM&IP
• CPC Class Codes: H04L 49/90 : Buffering arrangements
• CPC Class Codes: H04L 49/901 : using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 49/9063 : Intermediate storage in different physical parts of a node or terminal
• CPC Class Codes: H04L 49/9073 : Early interruption upon arrival of a fraction of a packet
• CPC Class Codes: H04L 61/00 : Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 : of different types
• CPC Class Codes: H04L 67/10 : in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 69/14 : Multichannel or multilink protocols
• CPC Class Codes: H04L 69/16 : Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 : Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/323 : in the physical layer [OSI layer 1]
• CPC Class Codes: H04L 69/329 : in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 : Network security protocols

Abstract

A network switch for network communications, wherein the network switch includes at least one data port interface supporting a plurality of data ports transmitting and receiving data at a first data rate and a second data rate. The at least one data port interface includes an ingress logic circuit in communication with the at least one data port interface for generating at least one of an ingress address resolution and a filtering search request. A CPU interface is provided and configured to communicate with a CPU. A shared hierarchical memory structure including an internal memory in communication with the at least one data port interface, and an external memory in communication with a memory management unit via an external memory interface is provided. A communication channel is provided for communicating data between the at least one data port interface, the internal memory, the CPU interface, and the memory management unit. Additionally, a unified table is provided, wherein the unified table is in connection with the communication channel, and the at least one data port interface. The unified table contains packet handling data for the network switch.

Claims

1. A network switch for network communications, said network switch comprising:

at least one data port interface supporting a plurality of data ports transmitting and receiving data at a first data rate and a second data rate, said at least one data port interface including an ingress logic circuit in communication with said at least one data port interface for generating at least one of an ingress address resolution and a filtering search request;

a CPU interface, said CPU interface configured to communicate with a CPU;

a shared hierarchical memory structure, wherein said shared hierarchical memory structure includes an internal memory in communication with the at least one data port interface, and an external memory in communication with a memory management unit via an external memory interface;

a communication channel, said communication channel for communicating data between said at least one data port interface, said internal memory, said CPU interface, and said memory management unit, and

a unified table, said unified table being in connection with the communication channel, and the at least one data port interface, said unified table containing packet handling data for the network switch;

wherein said unified table further comprises;

a single table having both address resolution and filtering information therein; and

a unified table logic circuit, said unified table logic circuit in connection with said single table,

wherein said unified table logic circuit is configured to receive the search request from the at least one data port interface and convert the search request into unified table form.

2. A method for conducting address resolution and filtering in a network switch, said method comprising the steps of:

receiving a packet on a port of a network switch;

generating a search request for address resolution of the packet;

searching a unified table having both address resolution information and filtering information therein with the search request to determine if a match to the search request is in the unified table;

determining if the unified table contains the match to the search request; and

generating a search response in accordance with an outcome of the determination;

wherein generating the search request further comprises;

generating an address resolution search request st in a port address resolution logic circuit;

receiving the address resolution search request in a unified table logic circuit; and

converting the search request into a unified table formatted search request.

3. A method for conducting address resolution and filtering in a network switch as recited in claim 2, wherein said converting step further comprises the steps of:

determining a request opcode for the search request, said request opcode representing a type of address resolution request; and

constructing a key for searching in the unified table,

wherein said key is constructed from the request opcode and a search key received from the port address resolution logic circuit.

4. A method for conducting address resolution and filtering in a network switch as recited in claim 2, wherein said step of searching the unified table further comprises searching the unified table with the unified table formatted search request.

5. A method for conducting address resolution and filtering in a network switch as recited in claim 2, wherein said step of generating a search response further comprises generating the search response with the unified table logic circuit and forwarding the search response to the port address resolution circuit.

6. A method for switching and filtering in a network switch, said method comprising the steps of:

receiving a packet at a port of a network switch;

generating an address resolution search request and a filtering search request in a port switch circuit;

receiving the address resolution search request and the filtering request in a unified table logic circuit;

converting the address resolution search request and the filtering search request into unified table formatted requests;

searching a unified table with the unified table formatted requests; and

generating a response to the address resolution search request and the filtering search request,

wherein the unified table contains both address resolution information and filtering information.

7. A method for switching and filtering in a network switch as recited in claim 6, wherein said converting step further comprises the steps of:

determining a request opcode; and

generating a table key,

wherein the table key is defined by the request opcode and a search key obtained from the port switch circuit.

8. A method for switching and filtering in a network switch as recited in claim 6, wherein said step of generating a response further comprises the steps of:

determining if a desired entry is within the unified table;

setting an F bit to 0 if the desired entry is determined to be within the unified table;

setting the F bit to 1 is the desired entry is determined not to be within the unified table;

constructing a search response in accordance with the determining step; and

transmitting the search response to the port switch circuit.

9. A network communications device comprising:

at least one data port interface supporting a plurality of data ports transmitting and receiving data at a first data rate and a second data rate, said at least one data port interface including an ingress logic circuit in communication with said at least one data port interface for generating at least one of an ingress address resolution and a filtering search request;

a CPU interface, said CPU interface configured to communicate with a CPU;

a memory structure in communication with the at least one data port interface;

a communication channel communicating data between said at least one data port interface, said memory structure, and said CPU interface; and

a unified table, said unified table being in connection with the communication channel, and the at least one data port interface, said unified table containing packet handling data for the network switch comprising address resolution information including L2 information, L3 information, and L4 information;

wherein said unified table further comprises;

a single table having both address resolution and filtering information therein; and

a unified table logic circuit, said unified table logic circuit in connection with said single table; and

Wherein said unified table logic circuit is configured to receive the search request from the at least one data port interface and convert the search request into unified table from.

10. A method for conducting address resolution and filtering in a network communications device said method comprising the steps of:

receiving a packet on a port of a network communications device;

generating a search request for address resolution of the packet;

searching a unified table having both address resolution information and filtering information therein with the search request to determine if a match to the search request is in the unified table;

determining if the unified table contains the match to the search request; and

generating a search response in accordance with an outcome of the determination;

wherein generating the search request further comprises;

generating an address resolution search request in a port address resolution logic circuit;

receiving the address resolution search request in a unified table logic circuit; and

converting the search request into a unified table formatted search request; and

wherein the address resolution information comprises address resolution information including L2 information, L3 information, and L4 information.

11. A method for conducting address resolution and filtering in a network communications device said method comprising the steps of:

receiving a packet on a port of a network communications device;

generating a search request for address resolution of the packet;

searching a unified table having both address resolution information and filtering information therein with the search request to determine if a match to the search request is in the unified table;

determining if the unified table contains the match to the search request; and

generating a search response in accordance with an outcome of the determination;

wherein generating the search request further comprises;

generating an address resolution search request in a port address resolution logic circuit;

receiving the address resolution search request in a unified table logic circuit; and

converting the search request into a unified table formatted search request;

wherein said converting step further comprises the steps of;

determining a request opcode for the search request, said request opcode representing a type of address resolution request; and

constructing a key for searching in the unified table;

wherein said key is constructed from the request opcode and a search key received from the port address resolution logic circuit; and

wherein the address resolution information comprises address resolution information including L2 information, L3 information, and L4 information.

12. A method for conducting address resolution and filtering in a network communications device said method comprising the steps of:

receiving a packet on a port of a network communications device;

generating a search request for address resolution of the packet;

searching a unified table having both address resolution information and filtering information therein with the search request to determine if a match to the search request is in the unified table;

determining if the unified table contains the match to the search request; and

generating a search response in accordance with an outcome of the determination;

wherein generating the search request further comprises;

generating an address resolution search request in a port address resolution logic circuit;

receiving the address resolution search request in a unified table logic circuit; and

converting the search request into a unified table formatted search request;

wherein said step of searching the. unified table further comprises searching the unified table with the unified table formatted search request; and

wherein the address resolution information comprises address resolution information including L2 information, L3 information, and L4 information.

13. A method for conducting address resolution and filtering in a network communications device, said method comprising the steps of:

receiving a packet on a port of a network communications device;

generating a search request. for address resolution of the packet;

searching a unified table having both address resolution information and filtering information therein with the search request to determine if a match to the search request is in the unified table;

determining if the unified table contains the match to the search, request; and

generating a search response in accordance with an outcome of the determination;

wherein generating the search request further comprises;

generating an address resolution search request in a port address resolution logic circuit;

receiving the address resolution search request in a unified table logic circuit; and

converting the search request into a, unified table formatted search request;

wherein said step of generating a search response further comprises generating the search response with the unified table logic circuit and forwarding the search response to the port address resolution circuit; and

wherein the address resolution information comprises address resolution information including L2 information, L3 information, and L4 information.