Quality of service half-duplex media access controller

A method for communicating on a half-duplex channel, the method comprising:

• transmitting a first frame;
• terminating transmission of the first frame when a collision is detected during the transmission;
• transmitting a second frame before retransmitting the first frame when the second frame has a higher class of service than the first frame, wherein each class of service has an attempt count and a predetermined attempt threshold;
• after terminating the transmission, incrementing the attempt count for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discarding each pending frame when the attempt count for that frame exceeds the predetermined attempt threshold for the class of service for that frame.

A method for communicating on a half-duplex channel, the method comprising:

• transmitting a first frame;
• terminating transmission of the first frame when a collision is detected during the transmission;
• transmitting a second frame before retransmitting the first frame when the second frame has a higher class of service than the first frame, wherein each class of service has an attempt count;
• after terminating the transmission, incrementing the attempt count for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discarding a given pending frame having an attempt count that exceeds a predetermined attempt threshold when the class of service of the given pending frame falls below a predetermined discard threshold.

Computer-readable media embodying instructions executable by a computer to perform a method for communicating on a half-duplex channel, the method comprising:

• transmitting a first frame;
• terminating transmission of the first frame when a collision is detected during the transmission;
• transmitting a second frame before retransmitting the first frame when the second frame has a higher class of service than the first frame, wherein each class of service has an attempt count;
• after terminating the transmission, incrementing the attempt count for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discarding all pending frames having an attempt count that exceeds a predetermined attempt threshold.

Computer-readable media embodying instructions executable by a computer to perform a method for communicating on a half-duplex channel, the method comprising:

• transmitting a first frame;
• terminating transmission of the first frame when a collision is detected during the transmission;
• transmitting a second frame before retransmitting the first frame when the second frame has a higher class of service than the first frame, wherein each class of service has an attempt count and a predetermined attempt threshold;
• after terminating the transmission, incrementing the attempt count for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discarding each pending frame when the attempt count for that frame exceeds the predetermined attempt threshold for the class of service for that frame.

Computer-readable media embodying instructions executable by a computer to perform a method for communicating on a half-duplex channel, the method comprising:

• transmitting a first frame;
• terminating transmission of the first frame when a collision is detected during the transmission;
• transmitting a second frame before retransmitting the first frame when the second frame has a higher class of service than the first frame, wherein each class of service has an attempt count;
• after terminating the transmission, incrementing the attempt count for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discarding a given pending frame having an attempt count that exceeds a predetermined attempt threshold when the class of service of the given pending frame falls below a predetermined discard threshold.

An apparatus for use in a half-duplex channel, the apparatus comprising:

• transmitting means for transmitting data over the half duplex channel;
• control means for terminating the transmitting means from transmitting a first frame of the data when a collision is detected during the transmission;
• first port means for including the transmitting means and for sending a replace signal that indicates a class of service of the first frame;
• switch control means for receiving the replace signal and for determining whether a second frame of the data has a higher class of service than the first frame in response to the replace signal,
• wherein the transmitting means transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• a plurality of attempt counter means, each for counting transmission attempts by the transmitter means of frames in one of a plurality of classes of service,
• wherein the control means, after terminating the transmission, increments the attempt counter means for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission, and discards all pending frames having an attempt count that exceeds a predetermined attempt threshold.

An apparatus for use in a half-duplex channel, the apparatus comprising:

• transmitting means for transmitting data over the half duplex channel;
• control means for terminating the transmitting means from transmitting a first frame of the data when a collision is detected during the transmission;
• first port means for including the transmitting means and for sending a replace signal that indicates a class of service of the first frame;
• switch control means for receiving the replace signal and for determining whether a second frame of the data has a higher class of service than the first frame in response to the replace signal,
• wherein the transmitting means transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame and each class of service has an attempt count and a predetermined attempt threshold;
• and
• a plurality of attempt counter means, each for counting transmission attempts by the transmitter means of frames in one of a plurality of classes of service;
• wherein the control means, after terminating the transmission, increments the attempt count means for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• wherein the control means discards each pending frame when the attempt count of transmission attempts by the attempt counter means for that frame exceeds the predetermined attempt threshold for the class of service for that frame.

An apparatus for use in a half-duplex channel, the apparatus comprising:

• transmitting means for transmitting data over the half duplex channel;
• control means for terminating the transmitting means from transmitting a first frame of the data when a collision is detected during the transmission;
• first port means for including the transmitting means and for sending a replace signal that indicates a class of service of the first frame;
• switch control means for receiving the replace signal and for determining whether a second frame of the data has a higher class of service than the first frame in response to the replace signal,
• wherein the transmitting means transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame and each class of service has an attempt count;
• and
• a plurality of attempt counter means, each for counting transmission attempts by the transmitter means of frames in one of a plurality of classes of service;
• wherein the control means, after terminating the transmission, increments the attempt count means for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• wherein the control means discards a given pending frame having an attempt count of transmission attempts by the attempt counter means that exceeds a predetermined attempt threshold when the class of service of the given pending frame falls below a predetermined discard threshold.

An apparatus for use in a half-duplex channel, the apparatus comprising:

• a transmitter to transmit data over the half duplex channel;
• a controller to terminate the transmitter from transmitting a first frame of the data when a collision is detected during the transmission;
• a first port that includes the transmitter and that sends a replace signal that indicates a class of service of the first frame;
• a switch controller that receives the replace signal and that determines whether a second frame of the data has a higher class of service than the first frame in response to the replace signal,
• wherein the transmitter, in response to the controller, transmits the second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• a plurality of attempt counters, each to count transmission attempts by the transmitter of frames in one of a plurality of classes of service;
• wherein the controller, after terminating the transmission, increments the attempt counter for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission, and discards all pending frames having an attempt count that exceeds a predetermined attempt threshold.

An apparatus for use in a half-duplex channel, the apparatus comprising:

• a transmitter to transmit data over the half duplex channel;
• a controller to terminate the transmitter from transmitting a first frame of the data when a collision is detected during the transmission;
• a first port that includes the transmitter and that sends a replace signal that indicates a class of service of the first frame;
• a switch controller that receives the replace signal and that determines whether a second frame of the data has a higher class of service than the first frame in response to the replace signal,
• wherein the transmitter, in response to the controller, transmits the second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame and each class of service has a predetermined attempt threshold;
• and
• a plurality of attempt counters, each to count transmission attempts by the first transmitter of frames in one of a plurality of classes of service;
• wherein the controller, after terminating the transmission of the transmitter, increments the attempt counter for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission by the transmitter;
• and
• wherein the controller discards each pending frame when the attempt count of transmission attempts by the attempt counter for that frame exceeds the predetermined attempt threshold for the class of service for that frame.

An apparatus for use in a half-duplex channel, the apparatus comprising:

• a transmitter to transmit data over the half duplex channel;
• a controller to terminate the transmitter from transmitting a first frame of the data when a collision is detected during the transmission;
• a first port that includes the transmitter and that sends a replace signal that indicates a class of service of the first frame;
• a switch controller that receives the replace signal and that determines whether a second frame of the data has a higher class of service than the first frame in response to the replace signal,
• wherein the transmitter, in response to the controller, transmits the second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• a plurality of attempt counters, each to count transmission attempts by the first transmitter of frames in one of a plurality of classes of service;
• wherein the controller, after terminating the transmission of the transmitter, increments the attempt counter for the class of service of the first frame and for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission by the transmitter;
• and
• wherein the controller discards a given pending frame having an attempt count of transmission attempts by the attempt counter that exceeds a predetermined attempt threshold when the class of service of the given pending frame falls below a predetermined discard threshold.

A network switch comprising:

• a first port in communication with a first half-duplex channel;
• a second port in communication with a second half-duplex channel;
• a memory wherein the first and third frames are the same and the second and fourth frames are the same;
• wherein the first port communicates with the second port via the memory;
• wherein the first port comprises:
• a first transmitter to transmit data over the first half-duplex channel;
• a first controller to terminate the first transmitter from transmitting a first frame of the data when a collision is detected during the transmission and to determine a class of service for each frame;
• and
• wherein the first transmitter transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• wherein the second port comprises:
• a second transmitter to transmit data over the second half-duplex channel;
• a second controller to terminate the second transmitter from transmitting a third frame of the data when a collision is detected during the transmission and to determine a class of service for each frame;
• and
• wherein the second transmitter transmits a fourth frame of the data before retransmitting the third frame when the fourth frame has a higher class of service than the third frame.

A network switch comprising:

• a first port in communication with a first half-duplex channel;
• a second port in communication with a second half-duplex channel;
• a memory;
• wherein the first port communicates with the second port via the memory;
• wherein the first port comprises:
• a first transmitter to transmit data over the first half-duplex channel;
• a first controller to terminate the first transmitter from transmitting a first frame of the data when a collision is detected during the transmission and to determine a class of service for each frame;
• and
• wherein the first transmitter transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• wherein the second port comprises:
• a second transmitter to transmit data over the second half-duplex channel;
• a second controller to terminate the second transmitter from transmitting a third frame of the data when a collision is detected during the transmission and to determine a class of service for each frame;
• and
• wherein the second transmitter transmits a fourth frame of the data before retransmitting the third frame when the fourth frame has a higher class of service than the third frame;
• and
• wherein the first controller, after terminating the first transmitter from transmitting:
• increments the attempt counter for the class of service of the first frame and the attempt counters for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discards all pending frames having an attempt count of transmission attempts by one of the attempt counters that exceeds a predetermined attempt threshold.

A network switch comprising:

• a first port in communication with a first half-duplex channel;
• a second port in communication with a second half-duplex channel;
• a memory;
• wherein the first port communicates with the second port via the memory;
• wherein the first port comprises:
• a first transmitter to transmit data over the first half-duplex channel;
• a first controller to terminate the first transmitter from transmitting a first frame of the data when a collision is detected during the transmission and to determine a class of service for each frame;
• and
• wherein the first transmitter transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• wherein the second port comprises:
• a second transmitter to transmit data over the second half-duplex channel;
• a second controller to terminate the second transmitter from transmitting a third frame of the data when a collision is detected during the transmission and to determine a class of service for each frame;
• and
• wherein the second transmitter transmits a fourth frame of the data before retransmitting the third frame when the fourth frame has a higher class of service than the third frame;
• and
• wherein each class of service has a predetermined attempt threshold, and wherein the first controller, after terminating the first transmitter from transmitting:
• increments the attempt counter for the class of service of the first frame and the attempt counters for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discards each pending frame having an attempt count of transmission attempts by one of the attempt counters that exceeds the predetermined attempt threshold for the class of service of that frame.

A network switch comprising:

• a first port in communication with a first half-duplex channel;
• a second port in communication with a second half-duplex channel;
• a memory;
• wherein the first port communicates with the second port via the memory;
• wherein the first port comprises:
• a first transmitter to transmit data over the first half-duplex channel;
• a first controller to terminate the first transmitter from transmitting a first frame of the data when a collision is detected during the transmission and to determine a class of service for each frame;
• and
• wherein the first transmitter transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• wherein the second port comprises:
• a second transmitter to transmit data over the second half-duplex channel;
• a second controller to terminate the second transmitter from transmitting a third frame of the data when a collision is detected during the transmission and to determine a class of service for each frame;
• and
• wherein the second transmitter transmits a fourth frame of the data before retransmitting the third frame when the fourth frame has a higher class of service than the third frame;
• and
• wherein the first controller, after terminating the first transmitter from transmitting:
• increments the attempt counter for the class of service of the first frame and the attempt counters for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discards a given pending frame having an attempt count of transmission attempts by the attempt counter of the class of service of the given pending frame that exceeds a predetermined attempt threshold when the class of service of the given pending frame falls below a predetermined discard threshold.

A network switch comprising:

• first port means for communicating on a first half-duplex channel;
• second port means for communicating on a second half-duplex channel;
• memory means for communicating with the first and second port means, wherein the first and third frames are the same and the second and fourth frames are the same;
• wherein the first port means comprises:
• first transmitter means for transmitting data over the first half-duplex channel;
• first controller means for terminating the first transmitter means from transmitting a first frame of the data when a collision is detected during the transmission and for determining a class of service for each frame, then increment;
• an attempt counter means to count transmission attempts by the first transmitter means, wherein the first controller means, after terminating the first transmitter means from transmitting:
• increments the attempt counter means;
• and
• discards the first frame when the attempt count of transmission attempts by the attempt counter means exceeds a predetermined attempt threshold;
• and
• wherein the first transmitter means transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• wherein the second port means comprises:
• second transmitter means for transmitting data over the second half-duplex channel;
• second controller means for terminating the second transmitter means from transmitting a third frame of the data where collision is detected during the transmission and for determining a class of service for each frame;
• wherein the second transmitter transmits a fourth frame of the data before retransmitting the third frame when the fourth frame has a higher class of service than the third frame.

A network switch comprising:

• first port means for communicating on a first half-duplex channel;
• second port means for communicating on a second half-duplex channel;
• memory means for communicating with the first and second port means;
• wherein the first port means comprises:
• first transmitter means for transmitting data over the first half-duplex channel;
• first controller means for terminating the first transmitter means from transmitting a first frame of the data when a collision is detected during the transmission and for determining a class of service for each frame;
• and
• wherein the first transmitter means transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• wherein the second port means comprises:
• second transmitter means for transmitting data over the second half-duplex channel;
• second controller means for terminating the second transmitter means from transmitting a third frame of the data when a collision is detected during the transmission and for determining a class of service for each frame;
• and
• wherein the second transmitter transmits a fourth frame of the data before retransmitting the third frame when the fourth frame has a higher class of service than the third frame;
• and
• wherein the first controller means, after terminating the first transmitter means from transmitting:
• increments the attempt counter for the class of service of the first frame and the attempt counters for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discards all pending frames having an attempt count of transmission attempts by one of the attempt counter means that exceeds a predetermined attempt threshold.

A network switch comprising:

• first port means for communicating on a first half-duplex channel;
• second port means for communicating on a second half-duplex channel;
• memory means for communicating with the first and second port means;
• wherein the first port means comprises:
• first transmitter means for transmitting data over the first half-duplex channel;
• first controller means for terminating the first transmitter means from transmitting a first frame of the data when a collision is detected during the transmission and for determining a class of service for each frame;
• and
• wherein the first transmitter means transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• wherein the second port means comprises:
• second transmitter means for transmitting data over the second half-duplex channel;
• second controller means for terminating the second transmitter means from transmitting a third frame of the data when a collision is detected during the transmission and for determining a class of service for each frame;
• and
• wherein the second transmitter transmits a fourth frame of the data before retransmitting the third frame when the fourth frame has a higher class of service than the third frame;
• and
• wherein each class of service has a predetermined attempt threshold, and wherein the first controller means, after terminating the first transmitter means from transmitting:
• increments the attempt counter for the class of service of the first frame and the attempt counters for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discards each pending frame having an attempt count of transmission attempts by one of the attempt counter means that exceeds the predetermined attempt threshold for the class of service of that frame.

A network switch comprising:

• first port means for communicating on a first half-duplex channel;
• second port means for communicating on a second half-duplex channel;
• memory means for communicating with the first and second port means;
• wherein the first port means comprises:
• first transmitter means for transmitting data over the first half-duplex channel;
• first controller means for terminating the first transmitter means from transmitting a first frame of the data when a collision is detected during the transmission and for determining a class of service for each frame;
• and
• wherein the first transmitter means transmits a second frame of the data before retransmitting the first frame when the second frame has a higher class of service than the first frame;
• and
• wherein the second port means comprises:
• second transmitter means for transmitting data over the second half-duplex channel;
• second controller means for terminating the second transmitter means from transmitting a third frame of the data when a collision is detected during the transmission and for determining a class of service for each frame;
• and
• wherein the second transmitter transmits a fourth frame of the data before retransmitting the third frame when the fourth frame has a higher class of service than the third frame;
• and
• wherein the first controller means, after terminating the first transmitter from transmitting:
• increments the attempt counter for the class of service of the first frame and the attempt counters for any other class of service that is not greater than the class of service of the first frame and for which a frame is pending transmission;
• and
• discards a given pending frame having an attempt count of transmission attempts by the attempt counter means of the class of service of the given pending frame that exceeds a predetermined attempt threshold when the class of service of the given pending frame falls below a predetermined discard threshold.