摘要:
Various techniques can be used to handle frames within multi-stage switching fabric. For example, in one method, a frame and an associated frame header are received at a switching fabric stage. The associated frame header includes a first field and a second field. The method selects one or more fabric points of exit within the switching fabric stage, based on the second field. The first field is used to select one or more other fabric points of exit within another switching fabric stage, and thus two different fields within the associated frame header specify fabric points of exit. The method then sends the frame to the selected fabric points of exit within the switching fabric stage.
摘要:
A self-adjusting load balancing among multiple fabric ports. A plurality of first values is received in response to receiving a first frame, wherein each of the first values is related to a quantity of data stored in a respective one of a plurality of buffers of fabric ports. First identifiers are also received, each of which corresponds to a respective one of a first subset of the plurality of buffers. A subset of the first identifiers is selected based on one or more of the first values. Thereafter one of the first identifiers contained in the selected subset is selected. Ultimately the first frame is transmitted to the buffer that corresponds to the selected one of the first identifiers.
摘要:
Various techniques can be used to handle frames within multi-stage switching fabric. For example, in one method, a frame and an associated frame header are received at a switching fabric stage. The associated frame header includes a first field and a second field. The method selects one or more fabric points of exit within the switching fabric stage, based on the second field. The first field is used to select one or more other fabric points of exit within another switching fabric stage, and thus two different fields within the associated frame header specify fabric points of exit. The method then sends the frame to the selected fabric points of exit within the switching fabric stage.
摘要:
The method can be implemented on a processor executing software instructions stored in memory. In one embodiment of the invention, the method includes receiving an Ethernet frame, wherein the Ethernet frame comprises an IP datagram, wherein the IP datagram comprises an IP header and an IP payload, wherein the IP payload comprises a User Datagram Protocol (UDP) header. When the Ethernet frame is received, a length in bytes of the IP payload of the IP datagram is calculated.
摘要:
Disclosed is a method and apparatus for checking link layer protocol frames such as Ethernet frames. The method can be implemented on a processor executing software instructions stored in memory. In one embodiment of the invention, the method includes receiving an Ethernet frame, and counting data bytes of the Ethernet frame to generate a total number of counted bytes. The total number of counted bytes can be used to calculate a data length of a datagram of the Ethernet frame. Once calculated, the datagram data length can be compared to a predetermined value. If the datagram length does not fall within an acceptable range of the predetermined value, the Ethernet frame may be dropped so that the Ethernet frame does not reach its final destination.
摘要:
An apparatus including a first buffer, a second buffer and a priority switch circuit. The first buffer is configured to store data of a first data stream having a first priority. The second buffer is configured to store data of a second data stream having a second priority. The priority switch circuit is coupled to the first buffer and the second buffer and is configured to interrupt a transmission of the first data stream from the first buffer upon detection of data of the second data stream and transmit data of the second data stream.
摘要:
The method can be implemented on a processor executing software instructions stored in memory. In one embodiment of the invention, the method includes receiving an Ethernet frame, wherein the Ethernet frame comprises a Transmission Control Protocol (TCP) header, wherein the TCP header comprises a TCP header length value. When the Ethernet frame is received, the TCP header length value is compared to a predetermined value.
摘要:
An apparatus and method for unconditionally loading a value into first memory of an first integrated circuit, which operates in one of several different modes depending on value stored in the first memory. In one embodiment, apparatus comprises a printed circuit board. The first integrated circuit (IC) is mounted on the printed circuit board, wherein the first IC comprises a first memory device, and wherein the first IC is configured to operate in a first mode when a first value is stored in the first memory device, and wherein the first IC is configured to operate in a second mode when a second value is stored in the first memory device. The printed circuit board also includes a second IC mounted thereon. The second IC comprises a second memory device that stores the first value. A third IC mounted on the printed circuit board is configured to provide a copy of the first value stored in the second memory device to the first IC for storage in the first memory device, wherein the third IC is configured to provide the copy of the first value to the first IC without condition.
摘要:
Disclosed is a method and circuit for synchronizing dual data buses. In one embodiment, the method includes a receiving circuit receiving first and second streams of multibit data portions transmitted via first and second parallel data buses, respectively, coupled thereto. The receiving circuit compares first-stream multibit data portions with a first predefined multibit data portion to identify a first-stream multibit data portion that matches the first predefined multibit data portion. The receiving circuit stores into a first FIFO, all first-stream multibit data portions that follow the identified first-stream multibit data portion. The receiving circuit also compares second-stream multibit data portions with a second predefined multibit data portion to identify a second-stream multibit data portion that matches the second predefined multibit data portion. The receiving circuit stores into a second FIFO, all second-stream multibit data portions that follow the identified second-stream multibit data portion.
摘要:
Disclosed is a circuit and method for reducing control code transmission between a line card and a switching fabric. One embodiment includes a memory receiving (and storing) data transmitted at a second rate during a first period of time. A quantity of data in the memory at time t, q(t), is compared with first, second, third, and fourth quantity values. The memory may receive data transmitted at the first rate if q(t) is less than the second, third and fourth values but greater than the first value. The memory may receive data transmitted at the third rate if q(t) is greater than the first, second, and third values but less than the fourth value. The memory may receive data transmitted at the second rate if q(t) is greater than the first and second values but less than the third and fourth values.