Message relaying scheme based on switching in units of flows

• US 6,772,219 B1
• Filed: 09/17/1999
• Issued: 08/03/2004
• Est. Priority Date: 09/18/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Shobatake, Yasuro
• Primary Examiner(s): Thompson, Marc D.
• Assistant Examiner(s): VU, THONG H
• Application Number:
  US09/398,210
• Time in Patent Office: 1,782 Days
• Field of Search: 709/227, 709/238, 709/247, 709/249, 370/356, 370/238, 370/422, 370/401, 370/249, 370/331, 370/392, 370/351
• US Class Current: 709/238
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/602 Multilayer or multiprotocol switching, e.g. IP switching

Abstract

A message relay device suitable for contructing a ultra-high-speed message relaying system is disclosed. In the message relay device, a flow is detected by a prescribed condition, while a bypass channel capable of transferring messages with an amount of calculations smaller than the case of handling messages by a default channel is set up, and the message transfer belonging to the flow is switched from the default channel to the bypass channel, while providing the connection-less communications on the default channel, so that it is possible to realize the message relaying with the ultra-high throughput by relieving the large amount of calculations inherently associated with the connection-less communications.

Claims

1. A message relay device connected with a plurality of routing processing devices for carrying out connection-less communications, for relaying a message from one routing processing device to another routing processing device, the message relay device comprising:

a plurality of Interface units provided in correspondence to the routing processing devices;

a switching unit connecting the plurality of interface units within the message relay device; and

a command unit for commanding the switching unit to set up a bypass communication channel within the message relay device in correspondence to an internal identifier which is an identifier defined within the message relay device for identifying at least a target interface unit corresponding to a relaying target routing processing device of each message;

wherein each interface unit determines a flow to which an input message entered from a corresponding routing processing device of each interface unit belongs and assigns the internal identifier to the input message according to the flow, transmits the input message to the switching unit, and receives an output message to be outputted to the corresponding routing processing device of each interface unit from the switching unit; and

the switching unit internally sets up the bypass communication channel within the message relay device according to the internal identifier in response to a command from the command unit, and internally switches messages transmitted from one interface unit of the message relay device to another interface unit using the bypass communication channel within the switching unit of the message relay device, the internal identifier being internal to the message relay device.

2. The message relay device of claim 1, wherein the command unit is contained in each interface unit so that a set up of the bypass communication channel is commanded from each interface unit to the switching unit.

3. The message relay device of claim 2, wherein the switching unit also transfers messages transmitted from one interface unit to another interface unit using a default communication channel that is set up in advance, and

each interface unit judges whether each arrived message arriving from the default communication channel is a message to be received by this interface unit or not by referring to each arrived message, and receives each arrived message when it is judged as a message to be received by this interface unit.

4. The message relay device of claim 3, wherein each interface unit obtains the internal identifier by checking a content of a prescribed region within a received message that is entered from the corresponding routing processing device of each interface unit and to be outputted to the default communication and/or an input port from which the received message is entered, and commands the switching unit to set up the bypass communication channel toward a target interface unit corresponding to a relaying target routing processing device of the received message that is to be set in correspondence to the internal identifier, when a prescribed condition is satisfied, and

each interface unit transmits a new message entered from the corresponding routing processing device of each interface unit to the bypass communication channel when the internal identifier that is assigned to the new message as a result of checking the content of the prescribed region within the new message and/or the input port from which the new message is entered, is set in correspondence to the bypass communication channel.

5. The message relay device of claim 3, wherein each interface unit has a plurality of message buffers that can be set in correspondence to different internal identifiers, and

each interface unit allocates one message buffer to a received message entered from the corresponding routing processing device of each interface unit and temporarily stores the received message in said one message buffer at a time of assigning the internal identifier to the received message if no message buffer is already set in correspondence to the internal identifier to be assigned to the received message, and transmits each message read out from each message buffer either to the bypass communication channel or the default communication channel which is selected according to a prescribed condition.

6. The message relay device of claim 2, wherein each interface unit commands a set up of the bypass communication channel toward a target interface unit corresponding to a relaying target routing processing device of each message that has a possibility of being entered from the corresponding routing processing device of each interface unit, as a communication channel to be set in correspondence to the internal identifier that is obtained from a content of a prescribed region within each message and/or an input port from which each message is expected to be entered, and each interface unit transmits a received message entered from the corresponding routing processing device of each interface unit to the bypass communication channel when the internal identifier that is assigned to the received message as a result of checking the content of the prescribed region within the received message and/or the input port from which the received message is entered, is set in correspondence to the bypass communication channel.

7. The message relay device of claim 1, further comprising a layer 3 processing unit connected with each interface unit, which analyzes each message including information of layer 3 and/or upper layers that is entered from a certain routing processing device into a corresponding interface unit, determines a flow to which messages to be assigned with the internal identifier belong, and commands each interface unit to assign the internal identifier when a message belonging to the flow is entered,

wherein the command unit is contained in the layer 3 processing unit so that a set up of the bypass communication channel is commanded from the layer 3 processing unit to the switching unit.

8. The message relay device of claim 7, wherein the layer 3 processing unit analyzes those messages which are control protocol messages for notifying in advance a flow to which messages that have possibilities of being entered from the certain routing processing device into the corresponding interface unit belong.

9. The message relay device of claim 7, wherein the layer 3 processing unit refers to a content of each message entered from the certain routing processing device into the corresponding interface unit, and transfers each message to the target interface unit corresponding to the relaying target routing processing device of each message using the default communication channel, and

the layer 3 processing unit analyzes those messages which are transmitted using the default communication channel.

10. The message relay device of claim 1, wherein each interface unit assigns the internal identifier to each message entered from the corresponding routing processing device of each interface unit by referring to at least a layer 2 destination address information within each message, where the relaying target routing processing device is identified according to the layer 2 destination address information.

11. The message relay device of claim 1, wherein each interface unit assigns the internal identifier to each message entered from the corresponding routing processing device of each interface unit by referring to at least a layer 2 header information within each message, where the relaying target routing processing device is identified according a relationship between the layer 2 header information and its relaying target routing processing device which is stored in advance.

12. The message relay device of claim 1, wherein each interface unit assigns the internal identifier to each message entered from the corresponding routing processing device of each interface unit by referring to information of layer 3, or layer 3 and upper layers, within each message.

13. The message relay device of claim 1, wherein each interface unit assigns the internal identifier to each message entered from the corresponding routing processing device of each interface unit by referring to at least an information capable of identifying a flow to which each message was regarded as belonging at the corresponding routing processing device, which is written in a specific region within each message, where the relaying target routing processing device is identified from a relationship between the flow and its relaying target routing processing device which is stored in advance.

14. The message relay device of claim 1, wherein each interface unit and the corresponding routing processing device of each interface unit are connected by a plurality of physical links or logical paths, and each interface unit assigns the internal identifier to each message entered from the corresponding routing processing device of each interface unit by checking at least a physical link or logical path from which each message is entered, where the relaying target routing processing device is identified according to a relationship between an information regarding the physical link or logical path from which each message is entered and its relaying target routing processing device which is stored in advance.

15. The message relay device of claim 1, wherein each interface unit and the corresponding routing processing device of each interface unit are connected by a plurality of physical links or logical paths,

each interface unit notifies an internal identifier information indicating the internal identifier and a type of messages to which the internal identifier will be assigned, to the target interface unit corresponding to the relaying target routing processing device, and attaches the internal identifier to each message that is transmitted to the switching unit using the bypass communication channel, and

the target interface unit corresponding to the relaying target routing processing device selects a physical link or logical path to be used in outputting each message to the relaying target routing processing device according to the internal identifier information notified for the internal identifier attached to each message received from the bypass communication channel.

16. The message relay device of claim 1, wherein the internal identifier is obtained from an information on a content of a prescribed region within each message and/or an input port from which each message is entered, by compressing its information amount to a fixed length.

17. The message relay device of claim 1, wherein the switching unit is formed by optical communication paths capable of realizing wavelength division multiplexed burst switching, in which the bypass communication channel is formed according to an optical wavelength, and

each interface unit allocates an optical wavelength to each message entered from the corresponding routing processing device of each interface unit according to the internal identifier, and transmits each message to the switching unit using the optical wavelength allocated to each message.

18. The message relay device of claim 17, wherein each interface unit has a buffer memory for storing each message in a region provided in correspondence to the internal identifier, and allocates the optical wavelength to the internal identifier when each message stored in the buffer memory satisfies a prescribed condition.

19. The message relay device of claim 17, wherein each interface unit selects one of a plurality of optical wavelengths, that are allocated in advance as optical wavelengths to be received uniquely by the target interface unit corresponding to the relaying target routing processing device, which is currently not used by other interface units, and transmits each message using said one of the plurality of optical wavelengths.

20. The message relay device of claim 19, wherein when there are a plurality of relaying target routing processing devices for a certain message, an interface unit which is a source of the certain message notifies to one interface unit corresponding to one relaying target, one optical wavelength selected for said one interface unit and information on other relaying targets, and transmits the certain message using said one optical wavelength, and

said one interface unit transmits a message obtained by copying the certain message received at said one optical wavelength, by using another optical wavelength selected for another interface unit corresponding to one of the other relaying targets.

21. The message relay device of claim 17, wherein each interface unit notifies the target interface unit corresponding to the relaying target routing processing device to uniquely receive one optical wavelength among those optical wavelengths for which no collision with other interface units occur, and transmits each message using said one optical wavelength.

22. The message relay device of claim 21, wherein each interface unit judges an optical wavelength which is currently not used in optical communication paths between each interface unit and the target interface unit corresponding to the relaying target routing processing device, as one of those optical wavelength for which no collision with other interface units occur.

23. The message relay device of claim 21, wherein when there are a plurality of relaying target routing processing devices for a certain message, a certain interface unit which is a source of the certain message notifies information on other relaying targets at a time of notifying a certain another interface unit corresponding to one relaying target to uniquely receive said one optical wavelength among those optical wavelengths for which no collision with other interface units occur,

said certain another interface unit notifies some other interface unit corresponding to one of the other relaying targets to uniquely receive another optical wavelength among those optical wavelengths for which no collision with other interface units occur, and upon receiving the certain message from the certain interface unit at said one optical wavelength notified from the certain interface unit, said certain another interface unit transmits a message obtained by copying the certain message, by using said another optical wavelength notified to said some other interface unit corresponding to one of the other relaying targets.

24. A message relay device connected with a plurality of routing processing devices for carrying out connection-less communications, for relaying a message from one routing processing device to another routing processing device, the message relay device comprising:

a plurality of interface units provided in correspondence to the routing processing devices; and

a switching unit connecting the plurality of interface units within the message relay device;

wherein each interface unit checks an input message entered from a corresponding routing processing device of each interface unit according to a protocol used in the input message, assigns to the input message an internal identifier which is an identifier defined within the message relay device for identifying at least a target interface unit corresponding to a relaying target routing processing device of the input message, has a buffer for storing the input message until a bypass communication channel within the switching unit from each interface unit toward another interface unit which is capable of transmitting messages assigned with the internal identifier becomes available at the switching unit, transmits the input message stored in the buffer to the switching unit while maintaining a protocol format of the input message as entered, and receives an output message to be outputted to the corresponding routing processing device of each interface unit from the switching unit; and

the switching unit internally switches messages within the message relay device transmitted from one interface unit to another interface unit within the message relay device using the bypass communication channel that is assigned to transfer the input message within the message relay device in accordance with the internal identifier that is internal to the message relay device.

25. A message relay device connected with a plurality of routing processing devices for carrying out connection-less communications, for relaying a message from one routing processing device to another routing processing device, the message relay device comprising:

a plurality of interface units provided in correspondence to the routing processing devices; and

a switching unit connecting the plurality of interface units within the message relay device using optical rings capable of transmitting optical signals in a plurality of wavelengths by multiplexing the optical signals;

wherein each interface unit transmits an input message entered from a corresponding routing processing device of each interface unit, through a communication channel in the optical rings toward a target interface corresponding to a relaying target routing processing device of the input message which is formed by using a wavelength determined according to the input message, receives an output message to be outputted to the corresponding routing processing device of each interface unit from the switching unit by selectively intercepting a wavelength uniquely allocated to each interface unit in the optical rings, and processes an intercepted message intercepted by selectively intercepting a wavelength commonly allocated to the plurality of interface units in the optical rings, according to an internal identifier that includes information indicating an interface unit within the message relay device which is a destination of the intercepted message, the internal identifier being internal to the message relay device.

26. A message relay method at a message relay device for relaying a message from one routing processing device to another routing processing device among a plurality of routing processing devices for carrying out connection-less communications, the method comprising the steps of:

determining a flow to which each message entered from one routing processing device belongs, according to a prescribed condition, by referring to a content of each message;

allocating a message buffer within the message relay device to the flow and storing each message into the message buffer;

assigning to the flow a special identifier capable or identifying a relaying target routing processing device of the flow, the special identifier being utilized solely within the message relay device;

reading out each message from the message buffer within the message relay device, assigning the special identifier to each message, and transmitting each message to a default communication channel within the message relay device which is formed such that each one of a plurality of connection target routing processing devices judges whether or not to receive each message arrived from the default communication channel according to the special identifier;

setting up a bypass communication channel within the message relay device through which each message will be transferred within the message relay device to the relaying target routing processing device, when the message buffer becomes a prescribed state; and

switching a transmission target of each message read out from the message buffer from the default communication channel to the bypass communication channel within the message relay device, when the bypass communication channel is set up within the message relay device.

27. A message relay method at a message relay device for relaying a message from one routing processing device to another routing processing device among a plurality of routing processing devices for carrying out connection-less communications, the method comprising the steps of:

entering a multicast connection set up request containing a multicast group address and information on a plurality of destination addresses corresponding to the multicast group address;

notifying a set of the multicast group address and the destination addresses to each routing processing device which is a relaying target of a multicast connection, prior to transmission of messages, when messages destined to the multicast group address subsequently arrive from a default communication channel within the message relay device which is formed such that each one of a plurality of connection target routing processing devices judges whether or not to receive each message arrived from the default communication channel according to a value of a destination address region;

collecting an information on an order relationship among relaying target routing processing devices on the multicast connection, in conjunction with a notification of the set of the multicast group address and the destination addresses;

allocating a message buffer within the message relay device to messages destined to the multicast group address;

storing messages destined to the multicast group address which are entered from one routing processing device into the message buffer within the message relay device;

reading out each message from the message buffer, and transmitting each message to the default communication channel;

setting up a bypass communication channel within the message relay device through which each message will be transferred to the relaying target routing processing devices according to the order relationship, when the message buffer becomes a prescribed state; and

switching a transmission target of each message read out from the message buffer within the message relay device from the default communication channel to the bypass communication channel within the message relay device, when the bypass communication channel is set up within the message relay device.