In-band Control Channels Using Dummy Packet Length Sequences
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Solution Overview
Problem
Communication networks, such as optical transport networks, face challenges in implementing in-band control channels due to limited packet inspection capabilities at receiving nodes, making it difficult to establish direct communication between router and optical nodes without complex out-of-band control channels.
Innovation Solution
Creating an in-band control channel by transmitting a sequence of dummy packets with varying lengths, where the sequence defines control commands, allowing nodes to decode and execute commands without inspecting the payload, enabling communication between router and optical nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If out of band control channels are used for communication between router and optical nodes, then control communication can be established, but operational and maintenance complexity increases significantly and router behavior changes are required
Solution Approach 1:
The patent merges control plane communication with data plane traffic by embedding control commands within data packets. The optical node processes both control and data traffic through the same physical interface and packet processing path, eliminating the need for separate out-of-band control channels and reducing operational complexity.
Solution Approach 2:
The optical node's packet processing capability is made universal by enabling it to handle both control plane packets and data plane traffic through the same interface. The node can decode control commands from incoming packets while simultaneously processing data traffic, making the interface multi-functional without requiring separate hardware paths.
2Reliability
If out of band control channels are used, then control communication is possible, but it is not suitable for operations related to physical link such as auto-discovery and link failure detection
Solution Approach 1:
The patent combines control plane operations with physical link operations by processing control commands and physical link events through the same packet processing path. This enables the system to handle auto-discovery, link failure detection, and other physical link operations directly through the data plane interface, improving adaptability to physical link conditions.
3Ease of operation
If in band control channels are implemented in a system with limited packet inspection capability, then direct communication can be achieved, but implementation becomes difficult
Solution Approach 1:
The patent extracts the control information from the packet payload by using packet length as the control mechanism. Instead of requiring the optical node to inspect packet contents to identify control commands, the system uses the packet length field to encode control information, which can be read without payload inspection capability.
Solution Approach 2:
The patent changes the parameter used for control signaling from packet content to packet length. By encoding control commands in the packet length field rather than requiring payload inspection, the system enables in-band control functionality in optical nodes with limited packet inspection capability, simplifying implementation.
4Productivity
If transponder performs transparent mapping of packets onto OTN frame, then packet transport is simplified, but transponder cannot decode in-band control-plane packets
Solution Approach 1:
The patent extracts control information from the packet payload by encoding it in the packet length field. This allows the transponder to handle control plane packets through transparent mapping without requiring decoding capability, as the control information is conveyed through packet length rather than payload content that would require inspection.
Solution Approach 2:
The patent changes the control information encoding from payload content to packet length parameter. This enables the transponder to maintain simple transparent mapping functionality while still supporting in-band control plane communication, as the length-based encoding can be processed without payload inspection or decoding capability.
Data Source
AI summary
An in band control channel is created between nodes of a communication network in which the nodes have limited capability of inspecting the payload of packets to be transported over the network. The in band control channel is created by transmitting a plurality of dummy packets, each dummy packet having one of a plurality of different predetermined lengths, the sequence of dummy packets defining a code corresponding to at least one control command.