Abstract: Systems, circuits, and methods for synchronizing devices in the time-domain are provided. A method, according to one implementation, includes determining a round-trip number based on a width of one cycle of a timestamping clock signal. The round-trip number is equal to a plurality of times that a clock signal is to be transmitted in a loop from a timing-leader component to a timing-follower component and back to the timing-leader component. The method also includes utilizing the timestamping clock signal to detect a cumulative time delay that results when the clock signal is transmitted in the loop a number of times equal to the round-trip number. The cumulative time delay is configured to enable synchronization of the timing-follower component with the timing-leader component.

Abstract: Systems, circuits, and methods for synchronizing devices in the time-domain are provided. A method, according to one implementation, includes determining a round-trip number based on a width of one cycle of a timestamping clock signal. The round-trip number is equal to a plurality of times that a clock signal is to be transmitted in a loop from a timing-leader component to a timing-follower component and back to the timing-leader component. The method also includes utilizing the timestamping clock signal to detect a cumulative time delay that results when the clock signal is transmitted in the loop a number of times equal to the round-trip number. The cumulative time delay is configured to enable synchronization of the timing-follower component with the timing-leader component.

Abstract: A method, a statistics subsystem, and a system use a combination of commercially available high speed memory and high density low speed memory to mitigate cost, space, control, and power issues associated with storing counters for statistics updates, while meeting the growing width and depth needs of multi-hundred gigabit Carrier Class data network devices. The method, statistics subsystem, and system offer a Counter Management Algorithm (CMA) that relies on rollover bits stored within data of counters. An update to the low speed memory is substantially faster than a rollover time for the counter in the high speed memory thereby allowing statistics to be cached in the high speed memory while updates take place to the low speed memory.

Abstract: Packet switch operating methods and packet switches assign a packet to a virtual interface. The virtual interface is associated with a plurality of tunnels. One of the plurality is designated a primary tunnel configured to accept packets. Other tunnels of the plurality are designated as backup tunnels and are configured to reject packets. The methods and packet switches also determine which of the plurality of tunnels is the primary tunnel and determine a packet switch port associated with the primary tunnel. The methods and packet switches egress the packet via the primary tunnel on the packet switch port associated with the primary tunnel.

Abstract: This document describes tools useful in relaying a data stream from a data device to a network tunnel, such as by injecting in-band control messages without impacting a data rate. For example, the tools may receive data packets on a first link and then relay the data packets to a data device on a second link. While doing so, the tools may periodically free an amount of link time by reducing the length of the relayed data packets by reducing the length of a header of each data packet. The tools may then consume the freed link time by sending a control message on the second link to the data device.

Abstract: This invention includes tools that prevent forwarding of a packet to a control plane of a packet switch. The tools receive a packet comprising indicia suggesting that the packet be forwarded to a control plane of a packet switch. After receiving the packet, the tools may modify the packet to prevent the packet from being forwarded to the control plane, intercept the packet before it is received by the control plane, or otherwise prevent the packet from being forwarded to the control plane. The tools may also forward the packet from a source port of a packet switch to a destination port of the packet switch without forwarding the packet to the control plane of the packet switch.

Abstract: Packet switch operating methods and packet switches receive a plurality of packets using a forwarding plane of the packet switch. Each packet of the plurality conforms to a different one of a plurality of forwarding information formats. The methods and packet switches modify each packet of the plurality to conform to a common forwarding information format instead of a respective one of the plurality of forwarding information formats and forward the modified packets of the plurality to a control plane of the packet switch.

Abstract: This document describes tools that enable data network equipment to use its permitted data rate or physical maximum rate even if one of its links fail or it transmits more data on some links than others. To do so, the tools may track how much of a permitted data rate is used by a group of physical links. If the group is using more than the permitted data rate, the tools may limit the group to that rate. If some of the physical links in the group fail, the tools enable the group to use either its permitted data rate or the physical maximum rate of the group. In addition, the tools allow unique permitted data rates in two directions by a group of physical links. The tools may be used at ingress or egress modules within equipment depending upon the application and implementation.

Abstract: This invention includes methods and packet switches that translate a packet between a switching format and a transport format. One packet switch receives a packet intended for a destination port of a packet switch from a switching fabric of the packet switch and determines, based on the destination port, a treatment to be applied to the packet. The packet switch then applies the treatment to the packet prior to forwarding the packet to the destination port. The treatment may include adding a transport identifier to the packet.

Abstract: This document describes tools useful in relaying a data stream from a data device to a network tunnel, such as by enabling virtual switching using a provisional identifier to conceal a user identifier. These tools, for example, may use an inexpensive switch module to create virtual switch instances. To do so, the tools may assign data packets to a virtual switch instance by mapping the data packets to a particular provisional identifier and then modifying the data packets to include the provisional identifier. The switch module may then forward the data packets based on the provisional identifier rather than on the user identifier. The tools may remove the provisional identifier before forwarding the data packets to a destination.

Abstract: Packet switch operating methods and packet switches provision a plurality of tunnels on a packet switch by associating each of the plurality of tunnels with a packet switch port and by configuring the packet switch to modify packets relayed by the tunnel to include a transport identifier associated with the tunnel. The tunnels of the plurality relay packets when permitted by a tunnel index. The plurality of tunnels and the tunnel index are associated with a virtual interface. The methods and packet switches also permit a first tunnel of the plurality of tunnels to relay packets by configuring the tunnel index to indicate the first tunnel. The tunnel index indicates only one tunnel. The methods and packet switches also enable a second tunnel of the plurality of tunnels to relay packets by configuring the tunnel index to indicate the second tunnel, thereby preventing the first tunnel from relaying packets.

Abstract: Packet switch operating methods and packet switches assign a packet to a virtual interface. The virtual interface is associated with a plurality of tunnels. One of the plurality is designated a primary tunnel configured to accept packets. Other tunnels of the plurality are designated as backup tunnels and are configured to reject packets. The methods and packet switches also determine which of the plurality of tunnels is the primary tunnel and determine a packet switch port associated with the primary tunnel. The methods and packet switches egress the packet via the primary tunnel on the packet switch port associated with the primary tunnel.

Abstract: Packet switch operating methods and packet switches assign a packet to a virtual interface. The virtual interface is associated with a plurality of tunnels. One of the plurality is designated a primary tunnel configured to accept packets. Other tunnels of the plurality are designated as backup tunnels and are configured to reject packets. The methods and packet switches also determine which of the plurality of tunnels is the primary tunnel and determine a packet switch port associated with the primary tunnel. The methods and packet switches egress the packet via the primary tunnel on the packet switch port associated with the primary tunnel.

Abstract: This invention includes methods and packet switches that modify duplicate packets to have different transport formats. A packet switch receives a plurality of duplicate packets from a switching fabric and modifies two or more of the duplicate packets so that the modified duplicate packets have different transport identifiers. The packet switch then transmits one of the duplicate packets on each of a plurality of ports of the packet switch.

Abstract: This document describes tools that forward data packets having tags conforming to different formats. In one embodiment, the tools receive a data packet on each of a plurality of ports, each data packet comprising a tag conforming to a different format. The tools relay the data packets to a port capable of transmitting tags conforming to a plurality of formats. In another embodiment, the tools receive a plurality of data packets on a source port comprising a plurality of logical source ports, each of which is associated with a unique tag. At least one data packet is received on each logical source port. Each data packet includes the tag associated with the logical source port on which the data packet is received. The tools map each data packet to one of a plurality of virtual switches based on the logical source port on which the data packet is received.

Abstract: Packet switch operating methods and packet switches receive a packet on a first port of the packet switch. The packet is addressed to a device that is in communication with a second port of forwarding circuitry of the packet switch and the packet has an Ethernet destination address field and an Ethernet source address field. The Ethernet destination address field includes a first address and the Ethernet source address field includes a second address. The methods and packet switches also forward the packet to an output queue associated with a third port of the forwarding circuitry, forward the packet from the output queue to the first port, and modify the packet so that the Ethernet destination address field comprises the second address instead of the first address.

Abstract: This document describes tools useful in relaying a data stream from a data device to a network tunnel. These tools may utilize an encapsulation scheme to convert data packets from a user format to a tunnel format required by a network tunnel. Similarly, the tools may utilize a de-encapsulation scheme to convert data packets from the tunnel format to the user format required by the user. The tools may also forward the data packets from a user network to the network tunnel and vice versa, through a conventional switch module. In some embodiments, the tools do so by modifying the data packets to add a provisional identifier recognized by the switch module to map a particular data stream into a particular network tunnel.

Abstract: This document describes tools useful in relaying a data stream from a data device to a network tunnel, such as by enabling virtual switching using a provisional identifier to conceal a user identifier. These tools, for example, may use an inexpensive switch module to create virtual switch instances. To do so, the tools may assign data packets to a virtual switch instance by mapping the data packets to a particular provisional identifier and then modifying the data packets to include the provisional identifier. The switch module may then forward the data packets based on the provisional identifier rather than on the user identifier. The tools may remove the provisional identifier before forwarding the data packets to a destination.

Abstract: This invention includes tools that prevent forwarding of a packet to a control plane of a packet switch. The tools receive a packet comprising indicia suggesting that the packet be forwarded to a control plane of a packet switch. After receiving the packet, the tools may modify the packet to prevent the packet from being forwarded to the control plane, intercept the packet before it is received by the control plane, or otherwise prevent the packet from being forwarded to the control plane. The tools may also forward the packet from a source port of a packet switch to a destination port of the packet switch without forwarding the packet to the control plane of the packet switch.

Abstract: This document describes tools useful in relaying a data stream from a data device to a network tunnel, such as by enabling virtual switching using a provisional identifier to conceal a user identifier. These tools, for example, may use an inexpensive switch module to create virtual switch instances. To do so, the tools may assign data packets to a virtual switch instance by mapping the data packets to a particular provisional identifier and then modifying the data packets to include the provisional identifier. The switch module may then forward the data packets based on the provisional identifier rather than on the user identifier. The tools may remove the provisional identifier before forwarding the data packets to a destination.