Protocol-to-protocol translator for interfacing disparate serial network nodes to a common parallel switching network

• US 5,535,373 A
• Filed: 02/15/1995
• Issued: 07/09/1996
• Est. Priority Date: 11/27/1991
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Olnowich, Howard T.
• Primary Examiner(s): Ellis, Richard L.
• Application Number:
  US08/390,893
• Time in Patent Office: 510 Days
• Field of Search: 395/500, 370/56, 370/60, 370/60.1, 370/94.1, 370/94.2
• US Class Current: 703/25
• CPC Class Codes: G06F 15/17375 One dimensional, e.g. linear array, ring
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 12/1881 with schedule organisation, e.g. priority, sequence management
• CPC Class Codes: H04L 49/101 using crossbar or matrix
• CPC Class Codes: H04L 49/1523 Parallel switch fabric planes
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/3018 Input queuing
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 7/0338 the correction of the phase error being performed by a feed forward loop
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks

Abstract

A generic network device includes a serial line switching apparatus for performing either parallel or serial communications amongst multiple nodes over switching networks. An aspect includes the adaptation of standard and proprietary serial interfaces using either optical or electrical transmission media to interface to a parallel switch. The converted serial data is routed to the selected destination through the parallel switch network, where it is received and converted back into a serial optical or electrical interface/protocol. Thus, the combination of the switching adapter and an ALLNODE parallel switching network make it feasible for serial message data to be switched and routed to various destinations. Further flexibility is provided which permits the switching adapter to be personalized to support any one of a number of standard and proprietary serial protocols. A personalization PROM specifies the particular serial protocol that each individual adapter is to support. The parallel switching network becomes a flexible media that interconnects and allows different serial protocols to communicate with each other; i.e., any number of different serial protocols can interface with the same parallel switch network. This allows every node of the parallel system to send and receive messages using its own native protocol. However, a node is not restricted to communicating only with others nodes using the same protocol, but is can communicate with any of the other nodes regardless of the serial protocol they use.

Claims

1. A protocol to protocol translator comprising:

serial receiving means for receiving a complete serial data message transmitted serially under a serial protocol from a node coupled to the translator;

a storage device including translation data corresponding to the serial protocol, the translation data including data useful for decoding data fields of the complete serial data message;

serial translation means coupled to the serial receiving means and to the storage device for translating the complete serial data message from the serial protocol into a parallel protocol in response to the translation data and for storing into a send buffer a translated complete parallel data message, the serial translation means including means for inserting into the translated complete parallel data message preselected header information used by a switch network for routing the translated complete parallel data message, the parallel protocol including an N bit wide parallel format where N is a positive integer greater than one;

parallel sending means coupled to the send buffer for sending a stored complete data message in the parallel protocol to a coupled input port of the switch network, the coupled input port comprising N parallel data paths for receiving an N bit wide parallel data message; and

a switch network, comprising;

a plurality of bufferless switching apparatus cascaded into a plurality of stages, said switching apparatus each including a plurality of switch inputs and a plurality of switch outputs, of the switch outputs included on each of said switching apparatus each coupled to a different one of the switching apparatus via a switch input of said different one of the switching apparatus, switch outputs of last stage switching apparatus each comprising a network output port and switch inputs of first stage switching apparatus each comprising a network input port;

the network output ports each coupled to a network input port through one of a plurality of nodes, each of said nodes comprising means for receiving a data message from a coupled network output port and means for sending a data message to a coupled network input port, said data message to a coupled network input port including a path connection request; and

said switching apparatus each further comprising

connection means for establishing a point-to-point communication path between any one of the network input ports and any one of the network output ports in response to said connection request received at said any one of the network input ports, said communication path for transmitting a data message received at said any one of the network input ports to said any one of the network output ports,

said connection means including asynchronous connection means for establishing asynchronously a plurality of simultaneously active point-to-point communication paths between a plurality of network input ports and a plurality of network output ports in response to a plurality of connection requests received separately or simultaneously at said plurality of network input ports, said simultaneously active communication paths for transmitting concurrently a plurality of data messages received separately or simultaneously at said plurality of network input ports to said plurality of network output ports.

2. The translator according to claim 1 wherein the serial translation means further includes:

means for appending to the translated complete parallel data message a CRC check word in response to the translation data; and

means for indicating when a network-ready data message is assembled in the send buffer.

3. The translator of claim 2, wherein the parallel sending means includes means for reading a 32-bit word from the send buffer about every 40 ns to achieve a parallel data message transmission rate of about 100 Megabytes per second.

4. The translator of claim 2, wherein the translation data includes preselected programmable data corresponding to a preselected serial protocol of the coupled node.

5. The translator of claim 4, wherein the parallel sending means includes means for receiving from the coupled input port of the switch network a reject signal issued by a destination of the translated complete parallel data message indicating an erroneous transmission of the translated complete parallel data message.

6. The translator of claim 5, wherein the translation means includes means for inserting into a current translated complete parallel data message a command for the parallel sending means to maintain in an active state connection paths in the switch network established for the current translated complete parallel data message for retries of a transmission of the current translated complete parallel data message.

7. The translator of claim 6, wherein the complete serial data message includes a link header having a start of frame delimeter (SOF) for indicating a beginning of a current data message, for identifying the serial protocol, for indicating to the parallel sending means to request that a new connection path be established in the switch network for the current data message, and for indicating to the parallel sending means to maintain an existing connection path in the switch network for use by the current data message.

8. The translator of claim 7, wherein the translation means includes SOF interpretation means for decoding a variable length SOF in the link header, the SOF interpretation means including:

SOF register means initialized from the PROM;

an SOF comparator coupled to the SOF register means for comparing link header data with SOF register means data; and

means for indicating that a valid SOF has been decoded including means for indicating a length of the valid SOF.

9. The translator of claim 6, wherein the complete serial data message includes a link trailer having an end of frame delimeter (EOF) for indicating an end of a current data message, for causing a connection path in the switch network used to transmit the current data message to be broken, and for causing the connection path in the switch network path used to transmit the current data message to be maintained in an active state.

10. The translator of claim 9, wherein the translation means includes EOF interpretation means for decoding a variable length EOF in the link trailer, the EOF interpretation means including:

EOF register means initialized from the PROM;

an EOF comparator coupled to the EOF register means for comparing link trailer data with EOF register means data; and

means for indicating that a valid EOF has been decoded including means for indicating a length of the valid EOF.

11. The translator of claim 10, wherein the parallel sending means includes means for sending an EOF signal to the send buffer for clearing the send buffer.

12. The translator of claim 10, further comprising continuous sequence means including:

registers for storing bit patterns;

comparators coupled to the registers for comparing received continuous sequences in a data message transmitted over a serial fiber data channel with the bit patterns; and

means for generating continuous sequences coupled to the comparators for sending the generated continuous sequences over the serial fiber data channel in response to a positive indication from any one of the comparators, said registers and means for generating each initialized from the PROM.

13. The translator of claim 12, further comprising:

link control means for processing a link control data message in the translated complete parallel data message, if any; and

means for removing from the translated complete parallel data message in the send buffer the link control data before sending the data in the send buffer.

14. The translator of claim 13, wherein the translation means includes:

means for cancelling a partially stored message or the translated complete parallel data message from the send buffer; and

means for indicating that the send buffer is full and for indicating that the send buffer is empty.

15. The translator of claim 14, further comprising:

parallel receiving means for receiving and storing in a receive buffer a complete parallel data message transmitted in the parallel protocol from an output port of the switch network coupled to the translator, the coupled output port comprising N parallel data paths for sending the parallel data message;

parallel translation means coupled to the parallel receiving means for translating the stored complete parallel data message from the parallel protocol into the serial protocol in response to the translation data, the translation means including means for serializing the data message; and

serial sending means for sending a data message translated into the serial protocol to the coupled node in the serial protocol.

16. The translator of claim 15, wherein the parallel translation means includes:

means for generating a link header and a link trailer including means for embedding the link header and the link trailer in a data message translated into the serial protocol.

17. The translator according to claim 16 wherein the parallel receiving means includes means for receiving the parallel data message at a rate of about 100 Megabytes per second.

18. A protocol to protocol translator comprising:

serial receiving means for receiving a complete serial data message transmitted serially under a serial protocol from a node coupled to the translator;

a storage device having translation data corresponding to the serial protocol and including preselected programmable data, the translation data including data useful for decoding data fields of the complete serial data message;

serial translation means coupled to the serial receiving means and to the storage device for translating the complete serial data message from the serial protocol into a parallel protocol in response to the translation data and for storing into a send buffer a translated complete parallel data message, the serial translation means including means for inserting into the translated complete parallel data message preselected header information used by a switch network for routing the translated complete parallel data message, the parallel protocol including an N bit wide parallel format where N is a positive integer greater than one;

parallel sending means coupled to the send buffer for sending a stored complete data message in the parallel protocol to a coupled input port of the switch network, the coupled input port comprising N parallel data paths for receiving an N bit wide parallel data message;

parallel receiving means for receiving and storing in a receive buffer a complete parallel data message transmitted in the parallel protocol from an output port of the switch network coupled to the translator, the coupled output port comprising N parallel data paths for sending the parallel data message;

parallel translation means coupled to the parallel receiving means for translating the stored complete parallel data message from the parallel protocol into the serial protocol in response to the translation data, the translation means including means for serializing the data message;

serial sending means for sending a data message translated into the serial protocol to the coupled node in the serial protocol;

the parallel sending means including means for receiving from the coupled input port of the switch network a reject signal issued by a destination of the translated complete parallel data message indicating an erroneous transmission of the translated complete parallel data message; and

a plurality of bufferless switching apparatus cascaded into a plurality of stages, said switching apparatus each including a plurality of switch inputs and a plurality of switch outputs, of the switch outputs included on each of said switching apparatus each coupled to a different one of the switching apparatus via a switch input of said different one of the switching apparatus, switch outputs of last stage switching apparatus each comprising a network output port and switch inputs of first stage switching apparatus each comprising a network input port;

the network output ports each coupled to a network input port through one of a plurality of nodes, each of said nodes comprising means for receiving a data message from a coupled network output port and means for sending a data message to a coupled network input port, said data message to a coupled network input port including a path connection request; and

said switching apparatus each further comprising

connection means for establishing a point-to-point communication path between any one of the network input ports and any one of the network output ports in response to said connection request received at said any one of the network input ports, said communication path for transmitting a data message received at said any one of the network input ports to said any one of the network output ports,

said connection means including asynchronous connection means for establishing asynchronously a plurality of simultaneously active point-to-point communication paths between a plurality of network input ports and a plurality of network output ports in response to a plurality of connection requests received separately or simultaneously at said plurality of network input ports, said simultaneously active communication paths for transmitting concurrently a plurality of data messages received separately or simultaneously at said plurality of network input ports to said plurality of network output ports.