ATM switch capable of routing IP packet

• US 6,147,999 A
• Filed: 05/27/1999
• Issued: 11/14/2000
• Est. Priority Date: 05/29/1998
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Honda, Masahiko, Yamashita, Mikiharu
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): LEE, CHI HO A
• Application Number:
  US09/321,241
• Time in Patent Office: 537 Days
• Field of Search: 370/355, 370/395, 370/254, 370/466, 370/347, 370/396, 370/397, 370/401, 370/409, 370/473, 370/474, 395/200
• US Class Current: 370/396
• CPC Class Codes: H04M 11/002 with telemetering systems telemetering in general G08C

Abstract

Disclosed is an ATM switch which comprises: an ATM switch unit; a switch control unit for controlling the ATM switch unit; one or more circuit accommodation units for connecting the switch with one or more external ATM networks, respectively, and an IP routing process unit for routing IP packets in a form of ATM cells. In the ATM switch, the IP routing process unit may comprise: a cell storage unit having a plurality of memories; a distributing means for distributing the ATM cells received from the ATM switch unit to the plurality of memories while grouping the ATM cells into each of the plurality of memories in accordance with an IP packet to which each of the ATM cells belongs; sending means for sending all the ATM cells belonging to an identical IP packet when the all the ATM cells belonging to the identical IP packet have been stored in respective one of the plurality of memories; and means for converting VPI/VCI (Virtual Path Identifier/ Virtual Channel Identifier) of the all the ATM cells belonging to the identical IP packet.

Claims

1. An ATM switch comprising:

an ATM switch unit;

a switch control unit for controlling said ATM switch unit;

one or more circuit accommodation units for receiving IP packets which have been segmented into ATM cells from one or more external ATM networks, respectively, and for transferring said ATM cells to said switch unit; and

an IP routing process unit for routing IP packets as segmented into their component ATM cells, without requiring reassembly of the segmented IP packets from their respective component ATM cells;

wherein said IP routing process unit comprises;

a cell storage unit having a plurality of memories, each of said plurality of memories having a capacity for storing a plurality of ATM cells;

a distributing means for distributing said ATM cells received from said ATM switch unit to said plurality of memories while grouping said ATM cells in each of said plurality of memories in accordance with an IP packet to which each of said ATM cells belongs;

a sending means for sending all the ATM cells belonging to an identical IP packet when said all the ATM cells belonging to said identical IP packet have been stored in a respective one of said plurality of memories; and

a means for converting a VPI/VCI (Virtual Path Identifier/Virtual Channel Identifier) of each of said all the ATM cells belonging to said identical IP packet.

2. The ATM switch according to claim 1, wherein each of said plurality of memories comprises a FIFO.

3. The ATM switch according to claim 1, wherein said distributing means comprises:

a means for storing connection identifiers each corresponding to a VPI/VCI before conversion and storing identification numbers each corresponding to each of non-vacant memories among said plurality of memories while holding correspondence between each of said connection identifiers and each of said identification numbers; and

a queue for queueing identification numbers of vacant memories among said plurality of memories.

4. The ATM switch according to claim 1, wherein said sending means detects whether or not said all the ATM cells in said identical IP packet have been stored in respective one of said plurality of memories by use of an identifier for identifying the last ATM cell among said all the ATM cells in said identical IP packet.

5. The ATM switch according to claim 1, wherein the converted VPI/VCI corresponds to an IP address of said IP packet to which said ATM cell belongs.

6. The ATM switch according to claim 5, wherein said IP routing process unit further comprises a routing table for holding a correspondence between said converted VPI/VCI and said IP address.

7. The ATM switch according to claim 6, wherein said IP routing process unit further comprises a means for updating contents of said routing table in response to generation of a routing protocol.

8. The ATM switch according to claim 1, wherein said ATM switch comprises a plurality of said IP routing process units.