Distributing ATM cells to output ports based upon destination information using ATM switch core and IP forwarding

• US 6,781,994 B1
• Filed: 08/24/1999
• Issued: 08/24/2004
• Est. Priority Date: 12/25/1997
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ikeda, Takashi, Watanabe, Masanori, Takahashi, Junichi, Mori, Kazuaki, Nogami, Kazuo, Horiguchi, Akihiro, Kishigami, Tohru, Hirai, Keitaro
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): HYUN, SOON D
• Application Number:
  US09/367,956
• Time in Patent Office: 1,827 Days
• Field of Search: 370/395.1, 370/397, 370/399, 370/395.3, 370/395.4, 370/395.52, 370/395.71, 370/389, 370/390, 370/392, 370/400, 370/401, 370/466, 370/467, 370/473, 370/474
• US Class Current: 370/395.1
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5651 Priority, marking, classes
• CPC Class Codes: H04L 2012/5658 using the AAL5
• CPC Class Codes: H04L 2012/5667 IP over ATM
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/621 Individual queue per connection or flow, e.g. per VC
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority
• CPC Class Codes: H04L 47/6225 Fixed service order, e.g. Round Robin
• CPC Class Codes: H04L 49/108 using shared central buffer
• CPC Class Codes: H04L 49/256 Routing or path finding in ATM switching fabrics
• CPC Class Codes: H04L 49/309 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]

Abstract

This invention has as its object to provide an ATM relay device which attains high-speed, large-capacity packet relaying by distributing the load on an IP forwarding unit without having to improve the operation speed, processing performance, and the like of an IP forwarding function. This invention has an ATM switch core (111) for distributing input ATM cells to corresponding ones of a plurality of output ports on the basis of their destination information. A plurality of IP forwarding units (120-1 to 120-n), which are provided in correspondence with the respective output ports of the ATM switch core (111) and have unique forwarding processing functions, execute predetermined forwarding processes for packets obtained by reassembling ATM cells input via the respective output ports. An SAR 121 assigns destination information that assumes different values in units of packets to ATM cells, which form each of packets having an identical address of those processed by the plurality of IP forwarding units (120-1 to 120-n). The ATM cells of a packet assigned identical destination information by the SAR 121 are stored in a PerVC queuing unit 112 by a predetermined volume, and are output in the format that stores the ATM cells by the predetermined volume.

Claims

1. An ATM relay device comprising:

an ATM switch core for distributing an input ATM cell to a corresponding one of a plurality of output ports on the basis of destination information thereof;

a plurality of forwarding means, provided in correspondence with the respective output ports of said ATM switch core, wherein each of the plurality of forwarding means has a unique forwarding processing function for executing a predetermined forwarding process for a packet obtained by reassembling ATM cells input via the respective output ports;

destination information assignment means for assigning destination information which assigns different values to ATM cells in unit of packets having at least one packet with an identical address to at least one other packet processed by said plurality of forwarding means; and

output means for storing ATM cells of packets assigned identical destination information by said destination information assignment means by a predetermined volume and outputting the ATM cells in a format that stores the ATM cells by the predetermined volume.

2. An ATM relay device according to claim 1, characterized in that said output means queues and stores packets having identical destination information in output queues in units of connections, and outputs the packets in units of protocol data units.

3. An ATM relay device according to claim 2, characterized in that whether or not ATM cells are stored in units of protocol data units is determined by an end flag.

4. An ATM relay device characterized by comprising:

ATM switch for distributing an input ATM cell to at least one of first, second, and third different ports on the basis of destination information thereof;

IP forwarding means for executing a forwarding process of an IP packet by receiving an ATM cell indicating that the destination information of the ATM cell is for forwarding via a first path connected to the first port of said ATM switch;

signaling means for executing a signal process of an IP packet by receiving an ATM cell indicating that the destination information of the ATM cell is for the signaling process, via a second path which is connected to the second port of said ATM switch and is physically different from the first path; and

management/control means for making management/control by receiving an ATM cell indicating that the destination information of the ATM cell is for management/control, via a third path which is connected to the third port of said ATM switch and is physically different from the first and second paths.

5. An ATM relay device comprising a packet forwarding function in a network layer using an ATM switch, comprising:

signaling processing means, provided in association with an ATM switch, for executing a signaling process by receiving a signaling packet from the ATM switch via a first link;

forwarding processing means, provided independently of said signaling processing means, for executing an IP packet forwarding process by hardware using a predetermined memory by receiving an IP packet via a second link which is physically different from the first link; and

CPU processing means for executing a CPU process by receiving at least a packet addressed to the ATM relay device and an IP packet which cannot undergo the IP packet forwarding process by said forwarding processing means, via a third link, which is physically different from the first and second links.

6. An ATM relay device according to claim 5, characterized in that the second link for the signaling process and the third link for the CPU process are physically an identical link.

7. An ATM relay device according to claim 5 or 6, characterized by comprising adjustment means for adjusting times to live of at least the packet addressed to the ATM relay device and the IP packet which cannot undergo the IP packet forwarding process by said forwarding processing means in said ATM relay device.