Abstract: A network device receives a packet having i) a first field that is to be updated by the network device, and ii) a second field that includes current error detection information corresponding to content of the packet, the content including the first field. The network device determines an update value that is to be added to a current value of the first field to generate a new value of the first field. The network device generates new error detection information using the current error detection information and the update value, and without using the current value of the first field. The network device modifies the second field to include the new error detection information, and modifies the first field to include the new value.

Abstract: A switching system comprises a controlling switch and a plurality of port extenders. One of the port extenders includes: at least one upstream port; multiple downstream ports; and a forwarding engine. A forwarding database is populated with entries indicating associations between i) respective network addresses corresponding to devices coupled to downstream ports, and ii) respective local downstream ports. The forwarding database excludes entries corresponding to network addresses corresponding to devices coupled to the at least one upstream port. The forwarding engine is configured to: for a first packet received via one of the local downstream ports, and having a destination network address in the forwarding database, forward the first packet to a different local downstream port indicated by the forwarding database.

Abstract: A switching system comprises a controlling switch and multiple port extenders. The controlling switch includes: a plurality of controlling switch ports; and a first packet processor having a first forwarding engine. The first forwarding engine is configured to forward packets received at any controlling switch port to any other controlling switch port. Each of at least some multiple port extenders includes: at least one local upstream port coupled to the controlling switch directly or via another port extender; a plurality of local downstream ports; and a second packet processor having a second forwarding engine and a forwarding database. The second forwarding engine is configured to forward packets i) received at the downstream ports, and ii) for which the forwarding database does not include forwarding information, only to the at least one upstream port. The second packet processor has reduced functionality as compared to the first packet processor.

Abstract: Aspects of the disclosure provide a method that includes receiving a first packet through a network at a first device. The first packet includes a first message generated according to a precision time protocol and a first encapsulation that encapsulates one or more fields of the first message. Further, the method includes security-verifying the first packet based on the first message and the first encapsulation, and processing the first message according to the precision time protocol after the first packet is security-verified.

Abstract: A sequence of packets is stored in a memory of the network device such that a current packet in the sequence of packets is stored at a predetermined distance following a preceding packet in the sequence. Lengths of corresponding ones of the packets stored in the memory are indicated in the memory. The packets are sequentially read from the memory based on the indicated lengths of corresponding ones of the packets stored in the memory. An operation is performed on the ones of the packets read from the memory. Subsequent to performing the operation, least some of the packets are written back to the memory. Ones of the packets are written to the memory beginning at a memory location following a respective preceding packet in the sequence by a predetermined distance.

Abstract: A network device receives a packet that conforms to a protocol that i) defines a time stamp field, ii) does not define a dedicated field for time correction information, and iii) defines a plurality of general purpose extension fields. The packet includes a time stamp generated by a source node in the time stamp field. The network device determines that the packet conforms to the protocol. The network device adds to the packet a new general purpose extension field. The new general purpose extension field specifies time correction information indicating a residence time of the packet in the network device, where the time correction information is for correcting the time specified by the time stamp.

Abstract: A network device includes one or more ports coupled to a network, a path determination module, and a clock synchronization module. The one or more ports receive a plurality of time synchronization packets from a master clock device. The path determination module identifies, based on respective path information included in each of at least some of the plurality of time synchronization packets, particular communication paths among two or more communication paths between the master clock device and the network device, via which the respective time synchronization packets traveled from the master clock device to the network device. The clock module determines a system time clock based on respective time information included in the at least some of the plurality of time synchronization packets and the identifications of the particular communication paths via which the respective time synchronization packets traveled from the master clock device to the network device.

Abstract: A forwarding engine in a network device selects one or more groups of multiple egress interfaces of the network device for forwarding packets received by the network device. An egress interface selector in the network device selects individual egress interfaces within the one or more groups selected by the forwarding engine. The egress interface selector includes a table associated with a first group of multiple egress interfaces, wherein elements in the table include values indicate individual egress interfaces in the first group. When the forwarding engine selects the first group, a table element selector of selects an element in the table to identify the individual egress interface for forwarding the packet.

Abstract: Aspects of the disclosure provide a method. The method includes generating a first message having a plurality of fields according to a precision time protocol, encapsulating one or more fields of the first message into a first encapsulation, preparing a first packet that includes the first message and the first encapsulation, and transmitting the first packet through a network.

Abstract: Aspects of the disclosure provide a method for collecting distributed counter values in a packet-switched system having multiple distributed packet processors. The method includes receiving a probe packet at a packet processor, storing a counter value corresponding to a flow processed by the packet processor for subsequent delivery to a management controller, and forwarding the probe packet to a next packet processor. The next packet processor stores a counter value of the next packet processor for subsequent delivery to the management controller.

Abstract: A first network device forwards a plurality of packets to the one or more network ports for transmission to a second network device, wherein ones of the packets include a field for indicating different, independent types of information. A field populator is configured to, for each of at least some packets among the plurality of packets: determine, from a set of different, independent types of information, a type of information to be included in the field of the packet according to a schedule known by the second network device, and populate the field in the packet only with data according to the type of information determined according to the schedule.

Abstract: A packet received by a network device via a network. A first portion of the packet is stored in a packet memory, the first portion including at least a payload of the packet. The packet is processed based on information from a header of the packet. After the packet is processed, a second portion of the packet is stored in the packet memory, the second portion including at least a portion of the header of the packet. When the packet is to be transmitted the first portion of the packet and the second portion of the packet are retrieved from the packet memory, and the first portion and the second portion are combined to generate a transmit packet.

Abstract: A network device comprises time measurement units configured to measure receipt times and transmit times of packets received/transmitted via network interfaces. One or more memories store configuration information that indicates certain network interface pairs and/or certain packet flows that are enabled for latency measurement. A packet processor includes a latency monitoring trigger unit configured to select, using the configuration information, packets that are forwarded between the certain network interface pairs and/or that belong to the certain packet flows for latency monitoring.

Abstract: A network device includes one or more ports coupled to a network, and a time synchronization module. The time synchronization module processes (i) respective path information, and (ii) respective time synchronization information included in each of at least some of a plurality of time synchronization packets received from a master clock device over two or more different communication paths and via at least one of the one or more ports, wherein the respective path information indicates a respective communication path in the network via which the respective time synchronization packet was received. The time synchronization module determines a system time clock responsive to the processing of the path information and the time synchronization information included in the at least some of the plurality of time synchronization packets.

Abstract: A network edge bridge including a first communication unit configured to receive a data packet from an access segment of a network, the data packet including a tunnel destination address and at least one Virtual Local Area Network (VLAN) tag, a tunnel header constructing unit configured to construct a tunnel header based on the VLAN tag. And a second communication unit that transmits the data packet, including the tunnel header, to an egress device corresponding to the tunnel destination address via an overlay interconnection layer.

Abstract: Network traffic that includes an Operations, Administration, and Maintenance (OAM) unit is received. A first data flow to which the OAM data unit belongs is identified from among a plurality of data flows of network traffic. Based on identifying the first flow of communication traffic to which the OAM data unit belongs, a first entry corresponding to the first flow is retrieved from a memory that stores OAM action data including a plurality of entries indicating how OAM data units in different flows of communication traffic are to be processed. The first entry is from among the plurality of entries and indicates how OAM data units in the first flow are to be processed, including whether the network device should modify the data unit as part of an OAM action. The OAM data unit is processed in accordance with the first entry.

Abstract: Aspects of the disclosure provide a method that includes receiving a first packet through a network at a first device. The first packet includes a first message generated according to a precision time protocol and a first encapsulation that encapsulates one or more fields of the first message. Further, the method includes security-verifying the first packet based on the first message and the first encapsulation, and processing the first message according to the precision time protocol after the first packet is security-verified.

Abstract: A method includes requesting a time maintained in a first clock domain, receiving, in a second clock domain, a first time value from the first clock domain in response to requesting the time maintained in the first clock domain, determining, in the second clock domain, a latency associated at least with receiving the first time value from the first clock domain, and determining a second time value based on the first time value and the determined latency.

Abstract: Techniques to load balance traffic in a network device or switch include a network device or switch having a first interface to receive a data unit or packet, a second interface to transmit the packet, and a mapper to map between virtual ports and physical ports. The network device includes hash value generator configured to generate a hash value based on information included in the packet and based on at least one virtual port. The hash value may be optionally modified to load balance egress traffic of the network device. The network device selects a particular virtual port for egress of the packet, such as by determining an index into an egress table based on the (modified) hash value. The packet is transmitted from the network device using a physical port mapped to the particular virtual port.

Abstract: A data unit is received at a network device associated with a link aggregate group. An initial key is determined based on information included in the data unit. Another key is generated based on a first field of the initial key and a second field of the initial key. A hash function is applied to the other key to generate a hash value. A communication link in the link aggregate group is determined based on the hash value, and the data unit is transmitted over the communication link.