Communication apparatus for reassembling packets received from network into message
First Claim
1. A communication apparatus for receiving a plurality of fixed length packets transmitted from a plurality of transmission source apparatus, and reassembling a communication message from a plurality of packets having the same transmission source address, each packet having a header field including a transmission source address and a message information field including an information block obtained by segmenting a message, comprising:
- a buffer memory divided into a plurality of memory blocks for storing packet data;
first memory means for storing addresses each indicating a vacant memory block within said buffer memory;
second memory means for storing next address pointers correspondingly with each transmission source address, each next address pointer indicating a memory block in which the data of a packet to be received next are stored;
third memory means for storing addresses correspondingly with each transmission source address, each address indicating a memory block in which the packet data including the first information block of a message are stored;
fourth memory means for storing addresses correspondingly with each transmission source address, each address indicating a memory block stored in which are the packet data including the first information block of a message allowed to be reassembled;
write control means which operates such that when there is received a packet including the first information block of a message transmitted upon segmentation into a plurality of information blocks, an address read from said first memory means is stored in said third memory means, the data of said received packet are stored in a vacant memory block indicated by said address, and another address read from said first memory means is stored in said second memory means and in said memory block storing said packet data; and
that when there is received a packet including one of the second and following information blocks of said message, the data of said received packet are stored in a memory block indicated by an address read from said second memory means, if said received packet does not include the last information block of said message, an address read from said first memory means is stored in said second memory means and in said memory block storing the data of said received packet, and if said received packet includes the last information block of said message, an address read from said third memory means is stored in said fourth memory means; and
read control means which operates such that the first information block of a message is read from the memory block indicated by an address read from said fourth memory means, and the second and following information blocks of said message are sequentially read in accordance with next address pointers read from respective memory blocks.
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Accused Products
Abstract
In a network having a plurality of node apparatus connected to a transmission line, each node apparatus segmenting a transmission message into information blocks of a predetermined length and transmitting them to the transmission line in the form of a fixed length packet (cell) having a source address, each node apparatus sequentially stores packets having different source addresses in vacant memory blocks of a buffer memory. There is written in each memory block the packet data as well as a next address pointer indicating a memory block in which the next received packet having the same source address is stored. When a packet containing the last information block of a message is received, stored in a read address queue is the address indicating the memory block which stores the first information block of the same packet. Reading the first block of a message from the buffer memory is executed in accordance with an address read from the read address queue, and reading the following blocks is executed in accordance with the next address pointer. Read/write of the buffer memory is alternately executed in units of memory block.
75 Citations
8 Claims
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1. A communication apparatus for receiving a plurality of fixed length packets transmitted from a plurality of transmission source apparatus, and reassembling a communication message from a plurality of packets having the same transmission source address, each packet having a header field including a transmission source address and a message information field including an information block obtained by segmenting a message, comprising:
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a buffer memory divided into a plurality of memory blocks for storing packet data; first memory means for storing addresses each indicating a vacant memory block within said buffer memory; second memory means for storing next address pointers correspondingly with each transmission source address, each next address pointer indicating a memory block in which the data of a packet to be received next are stored; third memory means for storing addresses correspondingly with each transmission source address, each address indicating a memory block in which the packet data including the first information block of a message are stored; fourth memory means for storing addresses correspondingly with each transmission source address, each address indicating a memory block stored in which are the packet data including the first information block of a message allowed to be reassembled; write control means which operates such that when there is received a packet including the first information block of a message transmitted upon segmentation into a plurality of information blocks, an address read from said first memory means is stored in said third memory means, the data of said received packet are stored in a vacant memory block indicated by said address, and another address read from said first memory means is stored in said second memory means and in said memory block storing said packet data; and that when there is received a packet including one of the second and following information blocks of said message, the data of said received packet are stored in a memory block indicated by an address read from said second memory means, if said received packet does not include the last information block of said message, an address read from said first memory means is stored in said second memory means and in said memory block storing the data of said received packet, and if said received packet includes the last information block of said message, an address read from said third memory means is stored in said fourth memory means; and read control means which operates such that the first information block of a message is read from the memory block indicated by an address read from said fourth memory means, and the second and following information blocks of said message are sequentially read in accordance with next address pointers read from respective memory blocks. - View Dependent Claims (2, 3, 4)
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5. A communication apparatus for receiving a plurality of fixed length packets transmitted from a plurality of transmission source apparatus, and reassembling a communication message from a plurality of packets having the same transmission source address, each packet having a header field including a transmission source address, a message information field including an information block obtained by segmenting a message and a code field for indicating the position of an information block within a message, comprising:
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a buffer memory divided into a plurality of memory blocks for storing packet data; first memory means for storing addresses each indicating a vacant memory block within said buffer memory; second memory means for storing addresses correspondingly with each transmission source address, each address indicating a memory block storing the data of a preceding packet; third memory means for storing addresses correspondingly with each transmission source address, each address indicating a memory block in which the packet data including the first information block of a message are stored; fourth memory means for storing addresses correspondingly with each transmission source address, each address indicating a memory block stored in which are the packet data including the first information block of a message allowed to be reassembled; write control means which operates such that when there is received a packet including the first information block of a message transmitted upon segmentation into a plurality of information blocks, an address read from said first memory means is stored in said second and third memory means, and the data of said received packet are stored in a vacant memory block indicated by said address; and that when there is received a packet including one of the second and following information blocks of said message, the data of said received packet are stored in a ,memory block indicated by an address read from said first memory means, and said address is stored as a next address pointer in a memory block at a predetermined memory area indicated by an address read from said second means, and if said received packet includes the last information block of said message, an address read from said third memory means is stored in said fourth memory means; and read control means which operates such that the first information block of a message is read from the memory block indicated by an address read from said fourth memory means, and the second and following information blocks of said message are sequentially read in accordance with next address pointers read from respective memory blocks. - View Dependent Claims (6, 7, 8)
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Specification