Packet communication processing method

• US 5,168,497 A
• Filed: 09/19/1989
• Issued: 12/01/1992
• Est. Priority Date: 09/21/1988
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ozaki, Seiichi, Asano, Michio, Takiyasu, Yoshihiro
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): KIZOU, HASSAN
• Application Number:
  US07/409,620
• Time in Patent Office: 1,169 Days
• Field of Search: 370/94.1, 370/94.2, 370/85.13, 370/85.14, 370/85.1, 370/91, 370/94.3, 370/60, 370/60.1, 371/32, 371/33, 371/12, 340/826, 340/827
• US Class Current: 370/394
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A packet communication processing method in a communication apparatus which performs communication with end apparatus for performing data link layer processing according to a data link protocol such as HDLC or similar protocol, in which method information frames (I frames) are received regardless of the rightness of a sending sequence number N(S) which is included in a control field (C field) in each of the received information so as to indicate the sequence of the I frames.

Claims

1. A packet communication processing method for communication of packets between a sending end apparatus which sends said packets and a destination end apparatus which receives said packets through a network system having a plurality of node apparatuses, in which at least one of said node apparatuses located on a route between said sending end apparatus and said destination end apparatus contains a communication apparatus for communicating control frames and information frames with an adjacent one of said node apparatuses or an adjacent one of said end apparatuses located on said route, the adjacent one node apparatus or the adjacent one end apparatus implementing a connection type data link protocol which is of high level data link control, synchronous data link control or of logical link control, each one of said information frames includes one of said packets and a sending sequence number for expressing a sequence for sending said information frames, said method comprising:

a first step in which said communication apparatus accepts information frames received from the adjacent one node apparatus or the adjacent one end apparatus regardless of whether said sending sequence number of each of said information frames is correct or not and sends out the packets included in said accepted information frames onto a destination end apparatus side route, in which said first step includes,

a step of counting a number of information frames received; and

a step of sending a receive-ready frame to the adjacent one node apparatus or to the adjacent one end apparatus whenever said number of information frames received reaches a predetermined value, for indicating that said communication apparatus is ready to receive new information frames;

a second step in which said destination end apparatus detects that packets sent from said sending end apparatus are missing, and in which said destination end apparatus sends a notification of the missing of packets to said sending end apparatus; and

a third step in which said sending end apparatus re-sends the missing packets or a series of packets containing said missing packets upon reception of said notification of the missing of packets.

2. A packet communication processing method according to claim 1, in which said receive-ready frame contains a receiving sequence number for notifying said adjacent node apparatus or said adjacent end apparatus of a confirmation of reception of said information frames, said receiving sequence number being obtained by incrementing by 1 the sending sequence number of a newest information frame of the information frames which said communication apparatus has received.

3. A packet communication processing method for communication of packets between a sending end apparatus which sends said packets and a destination end apparatus which receives said packets through a network system having a plurality of node apparatuses, in which at least one of said node apparatuses located on a route between said sending end apparatus and said destination end apparatus contains a communication apparatus for communicating control frames and information frames with an adjacent one of said node apparatuses or an adjacent one of said end apparatuses located on said route, the adjacent one node apparatus or the adjacent one end apparatus implementing a connection type data link protocol which is of high level data link control , synchronous data link control, or of logical link control, each one of said information frames includes one of said packets and a sending sequence number for expressing a sequence for sending said information frames, said method comprising:

a first step in which said communication apparatus accepts information frames received from the adjacent one node apparatus or the adjacent one end apparatus regardless of whether said sending sequence number of said information frames is correct or not and sends out the packet included in said accepted information frames onto a destination end apparatus side route, in which said first step includes,

a step in which said communication apparatus sends a receive-ready frame at a predetermined time period to the adjacent one node apparatus or to the adjacent one end apparatus for notifying said adjacent node apparatus or said adjacent end apparatus that said communication apparatus is ready to receive new information frames;

a second step in which said destination end apparatus detects that packets sent from said sending end apparatus are missing, and in which said destination end apparatus sends a notification of the missing of packets to said sending end apparatus; and

a third step in which said sending end apparatus re-sends the missing packets or a series of packets containing said missing packets upon reception of said notification of the missing of packets.

4. A packet communication processing method according to claim 3, further comprising a fourth step in which in response to the reception of a frame having a P bit set to "1", said communication apparatus sends one of said control frames or one of said information frames having an F bit set to "1" to said adjacent node apparatus or said adjacent end apparatus for notifying said adjacent node apparatus or said adjacent end apparatus that said communication apparatus is ready to receive the information frames, each one of said receive-ready frames being sent periodically in the first step and said control frame or information frame having an F bit set to "1" in the fourth step containing a receiving sequence number being obtained by an increment of 1 of the sending sequence number of a newest information frame of the information frames which were sent from said adjacent node apparatus or said adjacent end apparatus to said communication apparatus, and

each control frame or information frame which is not the receive-ready frame sent periodically in the first step and which is not the control frame or information frame having an F bit set to "1" in the fourth step contains a receiving sequence number which is equal to the receiving sequence number of the newer of said receive-ready frame sent periodically in the first step or said control or information frame having an F bit set to "1" in the fourth step.

5. A packet communication processing method for communication of packets between a sending end apparatus which sends said packets and a destination end apparatus which receives said packets through a network system having a plurality of node apparatuses, in which at least one of said node apparatuses located on a route between said sending end apparatus and said destination end apparatus contains a communication apparatus for communicating control frames and information frames with an adjacent one of said node apparatuses or an adjacent one of said end apparatuses located on said route, the adjacent one node apparatus or the adjacent one end apparatus implementing a connection type data link protocol which is of high level data link control, synchronous data link control, or of logical link control, each one of said information frames includes one of said packets and a sending sequence number for expressing a sequence for sending said information frames, said method comprising:

a step in which said communication apparatus sends information frames of not more than a predetermined number to said adjacent one node apparatus or said adjacent one end apparatus under a window control scheme which allows said communication apparatus to send a maximum of a predetermined number of information frames without receiving an acknowledgement frame which is sent from said adjacent node apparatus or said adjacent end apparatus in order to notify said communication apparatus of receipt of one or more of said information frames, under said window control scheme said communication apparatus can send unacknowledged information frames within the limit of said predetermined number;

a step in which said communication apparatus sends each one of said information frames without using a timer for a supervision of reception of said acknowledgement frame;

a step in which said communication apparatus sends the last one of said not more than the predetermined number of information frames with a P bit set to "1";

a step in which said communication apparatus sends further unacknowledged information frames within the limit of said predetermined number under said window control scheme in response to the reception of an acknowledgement frame which is sent from said adjacent node apparatus or said adjacent end apparatus and which has an F bit set to "1" and which indicates that said adjacent node apparatus or said adjacent end apparatus is ready to receive new information frames, said acknowledgement frame being issued by said adjacent node apparatus or said adjacent end apparatus in response to said information frame having its P bit set to "1";

a step in which said destination end apparatus detects that packets sent from said sending end apparatus are missing, and in which said destination end apparatus sends a notification of the missing of packets to said sending end apparatus; and

a step in which said sending end apparatus re-sends the missing packets or a series of packets containing said missing packets upon reception of said notification of the missing of packets.

6. A packet communication processing method according to claim 5, in which said information frame with its P bit set to "1" is sent without changing a value of an inner state variable of said communication apparatus which indicates that the communication apparatus has set a frame with its P bit set to "1" and has not received a response.

7. A packet communication processing method for communication of packets between a sending end apparatus which sends said packets and a destination end apparatus which receives said packets through a network system having a plurality of node apparatuses, in which at least one of said node apparatuses located on a route between said sending end apparatus and said destination end apparatus contains a communication apparatus for communicating control frames and information frames with an adjacent one of said node apparatuses or an adjacent one of said end apparatuses located on said route, the adjacent one node apparatus or the adjacent one end apparatus implementing a connection type data link protocol which is of high level data link control, synchronous data link control or of logical link control, each one of said information frames includes one of said packets and a sending sequence number for expressing a sequence for sending said information frames, said method comprising:

a step in which said adjacent node apparatus or said adjacent end apparatus sends a reject frame to said communication apparatus for indicating an information frame sent from said communication apparatus is missing;

a step in which said communication apparatus sends a mode reset requesting frame to said adjacent node apparatus or said adjacent end apparatus;

a step in which said adjacent node apparatus or said adjacent end apparatus sends a response frame which indicates said mode reset requesting frame is acknowledge, and said adjacent node apparatus or said adjacent end apparatus resets inner variables used for managing a receiving sequence number and said sending sequence number included in said frames;

a step in which said communication apparatus receives said response frame from said adjacent node apparatus or said adjacent end apparatus and then resets inner variables used for managing said receiving sequence number and said sending sequence number;

a step in which said destination end apparatus detects that packets sent from said sending end apparatus are missing, and in which said destination end apparatus sends a notification of the missing of packets to said sending end apparatus; and

a step in which said sending end apparatus re-sends the missing packets or a series of packets containing said missing packets upon reception of said notification of the missing of packets.

8. A packet communication processing method for communication of packets between a sending end apparatus which sends said packets and a destination end apparatus which receives said packets through a network system having a plurality of node apparatuses, in which at least one of said node apparatuses located on a route between said sending end apparatus and said destination end apparatus contains a communication apparatus for communicating control frames and information frames with an adjacent one of said node apparatuses or an adjacent one of said end apparatuses located on said route, said adjacent one node apparatus or said adjacent one end apparatus implementing a connection type data link protocol which is of high level data link control, synchronous data link control or of logical link control ,each one of said information frames includes one of said packets and a sending sequence number for expressing a sequence for sending said information frames, said method comprising:

a step in which when a higher layer processing part of said communication apparatus detects that there are information frames to be sent from said communication apparatus to said adjacent node apparatus or to said adjacent end apparatus, said higher layer processing part sends a send instruction to said data link layer processing part of said communication apparatus, said send instruction instructs said data link layer processing part to send out said information frames to said adjacent node apparatus to said adjacent end apparatus;

a step in which said higher layer processing part detects whether said information frames are sent out from said communication apparatus and when said information frames are not sent out after a predetermined time, said higher layer processing part sends said send instruction again, a time-out processing which is made up of said sending of said send instruction and said detection which are repeated until said information frames are set out or until a predetermined occurrence of repetition of said time-out processing;

a step in which if said information frames are not sent out after said predetermined occurrence of repetition of said time-out processing, said higher layer processing part sends a mode reset instruction to said data link layer processing part;

a step in which upon reception of said send instruction from said higher layer processing part, said data link layer processing part of said communication apparatus sends information frames of not more than a predetermined number to said adjacent one node apparatus or said adjacent one end apparatus under a window control scheme which allows said data link layer processing part of said communication apparatus to send a maximum of a predetermined number of information frames without receiving an acknowledgement frame which is sent from said adjacent node apparatus or said adjacent end apparatus in order to notify said communication apparatus of receipt of one or more of said information frames, under said window control scheme said data link layer processing part of said communication apparatus can send unacknowledged information frames within the limit of said predetermined number;

a step in which said adjacent note apparatus or said adjacent end apparatus detects one of said information frames sent from said communication apparatus is missing, and in which said adjacent node apparatus or said adjacent end apparatus sends a reject frame notifying said communication apparatus of said missing information frame, and in which after said sending of said reject frame, said adjacent node apparatus or said adjacent end apparatus discards all information frames received from said communication apparatus until reception of said missing one information frame;

a step in which said communication apparatus disregards reception of said reject frame sent from said adjacent node apparatus or said adjacent end apparatus;

a step in which upon reception of said mode reset instruction from said higher layer processing part, said data link layer processing part of said communication apparatus sends a mode reset request frame to said adjacent node apparatus or said adjacent end apparatus;

a step in which upon reception of said mode reset request frame, said adjacent node apparatus or said adjacent end apparatus sends a response frame notifying said mode reset request frame is acknowledged, and said adjacent node apparatus or said adjacent end apparatus resets inner variables used for managing a receiving sequence number and said sending sequence number included in said frames;

a step in which said data link layer processing part of said communication apparatus receives said response frame from said adjacent node apparatus or said adjacent end apparatus and then resets inner variables used for managing said receiving sequence number and said sending sequence number;

a step in which said destination end apparatus detects packets sent from said sending end apparatus are missing, and in which said destination end apparatus sends a notification of the missing of packets to said sending end apparatus; and

a step in which said sending end apparatus re-sends the missing packets or a series of packets containing said missing packets upon reception of said notification of the missing of packets.

9. A packet communication processing method for communication of packets between a sending end apparatus which sends said packets and a destination end apparatus which receives said packets through a network system having a plurality of node apparatuses, in which at least one of said node apparatuses located on a route between said sending end apparatus and said destination end apparatus contains a communication apparatus for communicating control frames and information frames with an adjacent one of said node apparatuses or an adjacent one of said end apparatuses located on said route, the adjacent one node apparatus or the adjacent one end apparatus implementing a connection type data link protocol which is of high level data link control, synchronous data link control or of logical link control, each one of said information frames includes one of said packets and a sending sequence number for expressing a sequence for sending said information frames, said method comprising:

a step in which when a busy state occurs in said communication apparatus which temporarily prohibits said communication apparatus from accepting received information frames into a buffer of said communication apparatus, said communication apparatus discards said information frames without notifying the adjacent node apparatus or the adjacent end apparatus of the occurrence of said busy state;

a step in which said communication apparatus accepts information frames into said buffer of said communication apparatus when said information frames are sent from said adjacent node apparatus or said adjacent end apparatus to said communication apparatus after said busy state is removed;

a step in which said destination end apparatus detects that packets sent from said sending end apparatus are missing, and in which said destination end apparatus sends a notification of the missing of packets to said sending end apparatus; and

a step in which said sending end apparatus re-sends the missing packets or a series of packets containing said missing packets upon reception of said notification of the missing of packets.