Multi-speed cut through operation in fibre channel switches
First Claim
1. A method for routing frames in a network, using a fibre channel switch element, comprising:
- (a) receiving a portion of a frame in a receive buffer of a port from among a plurality of ports for the fibre channel switch element;
where each port includes a receive segment with a receive buffer to receive the frame and a transmit segment to transmit the frame;
(b) determining a frame length threshold value for the port;
wherein the frame length threshold value is used to determine a length of the frame that has to be received at the receive buffer, before the frame is sent to the transmit segment of another port of the fibre channel switch element that transmits the frame; and
wherein a different frame length threshold value is used for different port operating speed;
(c) setting up status indicator that is based on the port'"'"'s operating speed, the frame length threshold value and an operating speed of the another port from where the frame is scheduled to be transmitted; and
(d) sending the status indicator to the transmit segment of the another port that uses the status indicator to determine when to request the frame from the port that received the frame in step (a);
wherein if a cut status in the status indicator does not match an operating speed of the another port, then the transmit segment of the another port selects a frame from a different source port and before transmitting the frame, tests a cut status of the newly selected frame to determine if the cut status matches the operating speed of the another port.
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Accused Products
Abstract
A method and system for routing frames based on a port'"'"'s speed using a fiber channel switch element is provided. The method includes, receiving a portion of a frame in a receive buffer of a port; determining a frame length threshold; and setting up a status bit based on the port'"'"'s speed, the frame length threshold and an amount of frame received. The status bit is sent to a transmit segment of the fiber channel switch element and the frame length threshold value is inversely proportional to the port'"'"'s speed. Also, if the receive buffer is almost full when a frame arrives at the receive port, then a cut status is based on a frames end of frame (“EOF”) value.
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Citations
16 Claims
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1. A method for routing frames in a network, using a fibre channel switch element, comprising:
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(a) receiving a portion of a frame in a receive buffer of a port from among a plurality of ports for the fibre channel switch element;
where each port includes a receive segment with a receive buffer to receive the frame and a transmit segment to transmit the frame;(b) determining a frame length threshold value for the port;
wherein the frame length threshold value is used to determine a length of the frame that has to be received at the receive buffer, before the frame is sent to the transmit segment of another port of the fibre channel switch element that transmits the frame; and
wherein a different frame length threshold value is used for different port operating speed;(c) setting up status indicator that is based on the port'"'"'s operating speed, the frame length threshold value and an operating speed of the another port from where the frame is scheduled to be transmitted; and (d) sending the status indicator to the transmit segment of the another port that uses the status indicator to determine when to request the frame from the port that received the frame in step (a); wherein if a cut status in the status indicator does not match an operating speed of the another port, then the transmit segment of the another port selects a frame from a different source port and before transmitting the frame, tests a cut status of the newly selected frame to determine if the cut status matches the operating speed of the another port. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A fibre channel switch element for routing frames, comprising:
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a plurality of ports, where each port includes a receive segment for receiving a frame and a transmit segment for transmitting the frame; wherein a port from among the plurality of ports, operating at a first operating speed is configured for receiving a portion of the frame in a receive buffer of the port;
determining a frame length threshold value; and
setting up a status bit based on (i) the first operating speed of the port receiving the portion of the frame;
(ii) a second operating speed of another port from where the frame is scheduled to be transmitted;
(iii) the frame length threshold value;
wherein the frame length threshold value is used to determine a length of the frame that has to be received at the receive buffer, before the frame is sent to a transmit segment of the another port; and
wherein a different frame length threshold value is used for different port operating speed; and
(iv) the portion of the frame received;wherein the status bit is used by the transmit segment of the another port to determine when to request the frame from the port that received the frame; and wherein if a cut status indicated by the status bit does not match the second operating speed of the another port, then the transmit segment selects another frame from a different source port and before transmitting the selected another frame, the transmit segment tests a cut status of the newly selected frame to determine if the cut status matches the operating speed of the another port. - View Dependent Claims (8, 9)
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10. A method for routing fibre channel frames using a fibre channel switch element having a plurality of ports, each port having a receive segment with a receive buffer to receive a frame and a transmit segment with a transmit buffer to transmit the frame, comprising:
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determining if the receive buffer is almost full when the frame arrives at the receive segment of a port from among the plurality of ports;
wherein the almost full status of the receive segment is a programmable condition defined by executable firmware code of the fibre channel switch element; and
if the receive buffer is almost full, setting a cut status based on the frames end of frame (“
EOF”
) value such that the frame is not moved from the receive buffer until the EOF for the frame is received; andif the receive buffer is not almost full, then the cut status is based on an operating speed of the port receiving the frame, an operating speed of another port that transmits the frame and a frame threshold length value; wherein the frame length threshold value is used to determine a length of the frame that has to be received at the receive buffer of the port, before the frame is transmitted to the transmit segment of the another port that transmits the frame; wherein a different frame length threshold value is used for different port operating speed; wherein the transmit segment uses the cut status to determine when to request the frame from the port that received the frame; and wherein if the transmit segment of the another port determines that a proper cut status is not set for the frame, then the transmit segment selects another frame from a different source port and before transmitting the selected another frame, determines if a cut status of the selected frame is proper. - View Dependent Claims (11)
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12. A method, comprising:
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(a) receiving a portion of a frame in a receive buffer of a port from among a plurality of ports of a network switch element;
where each port includes a receive segment with a receive buffer to receive the frame and a transmit segment to transmit the frame;(b) determining a frame length threshold value for the port;
wherein the frame length threshold value is used to determine a length of the frame that has to be received at the receive buffer, before the frame is sent to the transmit segment of another port of the switch element that transmits the frame; and
wherein a different frame length threshold value is used for different port operating speed;(c) setting up a status indicator that is based on the port'"'"'s operating speed, the frame length threshold value and an operating speed of the another port from where the frame is scheduled to be transmitted; and (d) sending the status indicator to the transmit segment of the another port that uses the status indicator to determine when to request the frame from the port that received the frame in step (a); wherein if a cut status in the status indicator does not match an operating speed of the another port, then the transmit segment of the another port selects a frame from a different source port and before transmitting the frame, tests a cut status of the newly selected frame to determine if the cut status matches the operating speed of the another port. - View Dependent Claims (13, 14, 15, 16)
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Specification