Reducing the memory requirements of a data switch

• US 20060041683A1
• Filed: 11/15/2002
• Published: 02/23/2006
• Est. Priority Date: 11/15/2002
• Status: Active Grant

• Current Assignee: Tahoe Research Limited (f/k/a Learndale Limited) (Vector Capital Corporation)
• Original Assignee: Infineon Technologies AG
• Inventors: George, Deepak, Subramanian, Ramakrishman Venkata, Mohamed, Gulam
• Granted Patent: US 8,185,652 B2
• Time in Patent Office: Days
• US Class Current: 709/245
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 49/00 Packet switching elements
• CPC Class Codes: H04L 49/206 Real Time traffic
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches

Abstract

A data switch (4) is proposed which can be operated such that it generates a MA table of MAC addresses of devices associated with some of its ports (9, 13, 15, 17, 19), but not the MAC addresses associated with one of the ports (11). Packets received by the switch, other than from the port (11), are assumed to be destined for the port (11) and are transmitted via the port (11). If the port (11) is connected to a network, and all the other ports are connected to a relatively small number of devices, such as one device per port, then the memory requirement to store the MA table is dramatically reduced.

Claims

1. A data switch having a plurality of ingress/egress ports and for transmitting data packets including a destination address, the data switch having address table construction means for generating a table containing associations between ports of the switch and MAC addresses of any devices connected to the switch via those ports, the address table construction means being operable to construct said table in respect of all but a first one of the ports.

2. A data switch according to claim 1 in which the address table construction means is further operable to construct said table in respect of all of the ports, according to a setting of a control register.

3-10. -10. (canceled)

11. An arrangement including a data switch for transmitting data packets including a destination address, the data switch comprising:

a first ingress/egress port and a plurality of other ingress/egress ports;

a table store configured to store a table containing associations between the plurality of other ingress/egress ports and MAC addresses of any devices connected to the switch via the plurality of other ingress/egress ports;

a switching fabric, and

a control unit operable to control the switching fabric, the control unit being arranged, upon receiving a data packet from any of the other ingress/egress ports having a destination address which is not stored in the table, to control the switching fabric to transmit the data packet to the first ingress/egress port.

12. The arrangement according to claim 11, wherein the first ingress/egress port is adapted to be connected to a communication network.

13. The arrangement according to claim 11, wherein at least one of the other ingress/egress ports is arranged to receive and transmit voice signals.

14. The arrangement according to claim 13, further comprising a microphone, a speaker, circuitry configured to transform sound signals received from the microphone into data packets and to transform data packets into control signals for the speaker, and wherein the circuitry is coupled to the at least one of the other ingress/egress ports arranged to receive and transmit voice signals.

15. The arrangement according to claim 14, further including sockets adapted to connect one or more of the other ingress/egress ports to devices which each have a MAC address.

16. The arrangement according to claim 14, wherein the first ingress/egress port is adapted to be connected to a communications network.

17. A method of operating a data switch comprising a first ingress/egress port and a plurality of other ingress/egress ports, the method including:

generating a table containing associations between at least the plurality of other ingress/egress ports of the switch and MAC addresses of any devices connected to the switch thereby,

stopping generation of the table before MAC addresses of at least some devices operably coupled through the first ingress/egress port are associated with the first ingress/egress port in the table.

18. The method of claim 17, wherein stopping generation of the table occurs after at least one MAC address of at least one device operably coupled through the first ingress/egress port is associated with the first ingress/egress port in the table.

19. The method of claim 18, further comprising:

receiving a data packet having a destination port MAC address absent from the generated table; and

forwarding the data packet to the first ingress/egress port.

20. The method of claim 19, wherein forwarding the data packet further comprising forwarding the data packet only if the data packet was received from one of the plurality of other ingress/egress ports.

21. The method of claim 17, further comprising:

converting analog audio signals to data packets; and

providing the data packets to one of the other ingress/egress ports.

22. A method of operating a data switch for switching data packets including a destination address, the data switch comprising a first ingress/egress port, a plurality of other ingress/egress ports, and a memory storing a table containing associations between the other ingress/egress ports and MAC addresses of any devices connected to the switch via the other ingress/egress ports, the method comprising:

receiving a data packet from any of the other ingress output ports, and

transmitting the data packet to the first ingress/egress port if the data packet contains a destination address that is absent from the table.

23. The method of claim 22, further comprising:

transmitting the data packet to a corresponding ingress/output port if the data packet contains a destination address that is present on the table.