The NEPTUNE Canada Communications Network

One of the objectives of the NEPTUNE Canada Regional Cable Observatory (RCO) is to provide a communications platform for undersea applications linked to the global Internet. Supported applications include sensor polling, command and control, file transfer, data streaming and video streaming. Ideally, the observatory infrastructure will also be forward compatible with as yet unknown applications. Achieving these goals requires a comprehensive communications architecture stretching from the most remote instruments to the Internet. The key components of this architecture are the observatory backbone and nodes, extension cables, junction boxes, serial device servers, shore based routers, and a backhaul link connecting the shore station to the Internet. The observatory backbone and nodes are integrated and delivered under a single supply contract. Junction boxes, extension cables, instrument pods and the science instruments and sensors are each procured separately and must be integrated and tested prior to deployment. The IEEE 802.1 and 802.3 (Ethernet) series of standards are relied upon to ensure compatibility between network elements. Link Aggregation Control Protocol (802.3ad) and Virtual Local Area Networking (802.1Q) provide essential functionality for observatory operation. The NEPTUNE Canada communications architecture immediately supports IPv4 and key underwater components also support IPv6. The NEPTUNE Canada design allows expansion through the addition of nodes and junction boxes, upgrade from 2.5 Gb/s to 10 Gb/s optical channels, and extension of the backbone cable. The network design selected by NEPTUNE Canada has many benefits, but is not ideal in all respects. Nonetheless, an analysis of the design risks and tradeoffs shows that most of these are well managed by the selected design. Future generations of RCOs can extend the NEPTUNE Canada architecture by increasing the number of optical fibers, increasing the optical channel data rate, or introducing node-to-node optical channels.