An Optical channel Data Unit flex (ODUflex) resizing method, node, and network include determining that the ODUflex needs resizing, wherein the ODUflex is configured in the network on a current path between the node and a second node in the network; when the resizing is a decrease, reducing a size of the ODUflex by i) a resize decrease operation using a control plane or ii) a Link Aggregation Group and Make-Before-Break operation; and, when the resizing is an increase, increasing a size of the ODUflex by i) a resize increase operation using a control plane or ii) a Link Aggregation Group and Make-Before-Break operation. The method provides hitless resizing without using ITU Recommendation G.7044/Y.1347 (10/11) and can perform the reducing or the increasing changing bandwidth of the ODUflex by approximately 100 G in less than a second.

Embodiments of this application disclose a service resource preconfiguration method and device, and a system. The method includes establishing a first working path, sending a first path message from a first node to a second node, the first path message including an instruction to the second node to preconfigure a second channel resource; and preconfiguring the second channel resource based on the first path message. Fast automatic service recovery can be implemented, and fault recovery performance can be improved.

Systems and methods include receiving (102) a plurality of symbols that are part of a defined Digital Signal Processing (DSP) frame for coherent optical communication, wherein the DSP frame structure has a messaging channel incorporated therein that includes a subset of the plurality of symbols; capturing (104) multiple samples of the messaging channel; and determining (106) a message in the messaging channel based on analysis of the multiple samples. The method can further include transmitting (108), in the messaging channel, a reply to the message with the reply being repeated multiple times. The analysis is performed prior to Forward Error Correction (FEC) decoding on the data path.

Systems and methods are disclosed for providing a messaging channel within a coherent optical Digital Signal Processing (DSP) frame. A coherent optical modem generates a DSP frame comprising a plurality of symbols, including padding symbols and reserved symbols, and defines a messaging channel by modulating a message on at least a subset of the padding symbols or the reserved symbols. The messaging channel enables low-bandwidth information exchange prior to Forward Error Correction (FEC) decoding on the data path, facilitating communication before establishment of a stable bidirectional link. The message may be carried in padding symbols, reserved symbols randomized to avoid strong tones, or vendor-specific symbols assigned in the first DSP sub-frame. Example message content includes hardware details, identifiers, version information, counters, payload data, and I/Q tributary mapping. The approach is applicable to DSP frames compliant with ITU-T G.709.3 Amendment 1, OIF-400ZR, or OpenZR+ specifications.

A service protection method includes a first node that determines that a fault has occurred on a first working path, and generates a service switching message based on the fault on the first working path. The first node sends the service switching message on a first protection path, where the service switching message indicates to adjust a bandwidth of a service from a guard bandwidth to a target bandwidth, where the guard bandwidth represents a pre-occupied bandwidth of the first protection path before the service is transmitted, where the target bandwidth represents an occupied bandwidth for transmitting the service on the first protection path, and where the guard bandwidth is less than the target bandwidth.

Optical networks, network elements, and methods of use are described herein, including an optical network comprising head-end and tail-end network elements, an optical multiplex section (OMS) connecting the head-end and tail-end network elements, and one or more intermediate line amplifiers in the OMS between the head-end and tail-end network elements. The head-end network element may store first information indicative of a first tilt control section having the head-end and tail-end network elements as endpoints; determine information indicative of a change in topology of the OMS, such as that a first intermediate line amplifier has switched from a non-monitoring to a monitoring mode; and store second information indicative of a second tilt control section having the head-end network element and a new tail-end network element, such as the first intermediate line amplifier.