The present invention includes novel techniques, apparatus, and systems for optical WDM communications. Tunable lasers are employed to generate respective subcarrier frequencies which represent subchannels of an ITU channel to which client signals can be mapped. In one embodiment, subchannels are polarization interleaved to reduce crosstalk. In another embodiment, polarization multiplexing is used to increase the spectral density. Client circuits can be divided and combined with one another before being mapped, independent of one another, to individual subchannels within and across ITU channels. A crosspoint switch can be used to control the client to subchannel mapping, thereby enabling subchannel protection switching and hitless wavelength switching. Network architectures and subchannel transponders, muxponders and crossponders are disclosed, and techniques are employed (at the subchannel level/layer), to facilitate the desired optical routing, switching, concatenation and protection of the client circuits mapped to these subchannels across the nodes of a WDM network.

A method of enabling access to content in a network implementing Internet Protocol version 6 (IPv6) is described, the method including accessing a content addressing file including entries each comprising a content portion location associated with the content portion. The content portion location associated with the content portion is extracted for an entry and, based on the content portion location, a section of an IPv6 address for the content portion is formed. Methods of addressing content for storage and retrieving content are also described.

Various example embodiments relate generally to supporting flow-specific fast rerouting of source routed packets in communication networks. Various example embodiments for supporting flow-specific fast rerouting of source routed packets may be configured to support flow-specific fast rerouting of source routed packets based on use of various source routing protocols which may be based on various underlying communication protocols. Various example embodiments for supporting flow-specific fast rerouting of source routed packets in communication networks may be configured to support flow-specific fast rerouting of source routed packets by supporting use of a source routed packet including a payload and a header where the header encodes a set of hops of a primary path for the source routed packet and where the header also encodes a set of hops of a protection path configured to protect one of the hops of the primary path for the source routed packet.

Systems, methods, and computer-readable media for updating configurations in sensors deployed in multi-layer virtualized environments. In some examples, a system can track information of sensors and collectors in the network. In response to determining that a specific collector becomes unavailable (e.g., the specific collector is down, offline or becomes unsupported), the system can determine affected sensors corresponding to the specific collector, determine a new collector among active collectors of the network for each of the affected sensors, and dynamically update configuration and settings of the affected sensors to maintain proper collector-to-sensor mappings and other settings on the affected sensors.

A method for enhanced use of a switching fabric within a central office point of delivery of a broadband access network of a telecommunications network includes: transporting data packets to or from a specific remote access node using a pseudo wire, wherein the pseudo wire spans at least the specific remote access node and the switching fabric. Using the pseudo wire comprises using first header label information for a data packet to be received by the specific remote access node and using second header label information for a data packet sent from the specific remote access node. Segment routing of the data packets is used involving third header label information for the data packet to be received by the specific remote access node and involving fourth header label information for the data packet sent from the specific remote access node.

Systems, methods, and computer-readable media are provided for determining a packet's round trip time (RTT) in a network. A system can receive information of a packet sent by a component of the network and further determine an expected acknowledgement (ACK) sequence number associated with the packet based upon received information of the packet. The system can receive information of a subsequent packet received by the component and determine an ACK sequence number and a receiving time of the subsequent packet. In response to determining that the ACK sequence number of the subsequent TCP packet matches the expected ACK sequence number, the system can determine a round trip time (RTT) of the packet based upon the received information of the packet and the received information of the subsequent packet.

A method and apparatus for path computation includes generating a path computation element communication protocol (PCEP) message, whereby the PCEP message comprises a characteristic associated with a level of protection of a Protection Label Switch path (LSP) with a Working LSP; and transmitting the PCEP message for path computation.

Methods of establishing an entry corresponding to equal-cost paths, network devices and non-transitory machine-readable storage mediums are provided. In one aspect, a network device assigns an inner label and an outer label for each of N paths configured to be equal cost with each other between the network device and a destination network device, wherein the respective inner labels corresponding to the paths are same with each other; createestablishes a FIB entry, wherein the FIB entry includes an address of the destination network device, the number of ECMP entries in an ECMP table corresponding to the paths, and the same inner label, and the number of ECMP entries in the ECMP table is equal to a preset fixed value; and assigns at least one ECMP entry for each of the paths based on the number N of the paths and the fixed value.

A data packet from a sub-virtual routing and forwarding (sub-VRF) in a virtual routing and forwarding (VRF) is received. The VRF includes more than one sub-VRF. A value in a Border Gateway Protocol (BGP) attribute attached to the data packet is determined. Based on the value in the BGP attribute, whether to route the data packet to a different sub-VRF in the VRF is determined.

Techniques are described for advertising constraint-based path computation (e.g., flexible-algorithm) through a constrained network topology. For example, a network device comprises a memory and one or more programmable processors operably coupled to the memory, wherein the one or more programmable processors are configured to generate a packet including a segment identifier (SID) offset, wherein the SID offset is an offset value associated with the flexible-algorithm. The one or more programmable processors of the network device are also configured to send, to at least one other network device of the plurality of network devices, the SID offset to enable the at least one other network device to derive a node segment identifier for the at least one other network device to participate in the flexible-algorithm.