As Bill Parr and Patrick Cody attempt to tackle the Eastern Shore’s last mile Broadband connectivity issues, the challenges posed the commercial, public/private, and first responder needs are at once daunting, yet on the other hand very exciting. The excitement is understandable, but given the Shore’s geographic disparateness, this may require a fundamental research effort relative to the current, actual topology of the physical network. Although our local router-level topology and how inter-connected our Autonomous Systems (cell towers, routers or switches, and fiber-optic cables) are fairly well understood, outside the backbone running up the spine of the Shore, knowledge of how the physical Internet, where the constructed US long-haul fiber-optic network has a significant amount of observed infrastructure sharing, actually makes it here, is sometimes not fully visualized. At a high level, engineers consider conduits that are shared by many service providers as inherently risky since damage to that conduit will affect several providers.
A University of Wisconsin paper InterTubes: A Study of the US Long-haul Fiber-optic Infrastructure (PDF), by authors — Ramakrishnan Durairajan and Paul Barford from the University of Wisconsin-Madison, Joel Sommers from Colgate University, and Walter Willinger from NIKSUN, Inc., created a detailed analysis of our long-haul fiber-optic network map. The analysis was done by using geocoded network maps and the ArcGIS framework, and is unprecedented both in terms of accuracy and ability for validation.
Many of the maps and ensuing information did not include details the researchers needed, such as precise geographic locations of all the long-haul routes deployed or used by the corresponding networks. According to the authors, “We made extensive use of previously neglected or under-utilized data sources in the form of public records from federal, state, or municipal agencies or documentation generated by commercial entities (e.g., commercial fiber map providers, utility rights-of-way information, environmental impact statements, fiber sharing arrangements by the different states’ transportation departments).”
Author Carl Barford states, “A striking characteristic of the constructed U.S. long-haul fiber-optic network is the significant amount of observed infrastructure sharing.”
Infrastructure sharing means that multiple service providers jointly-use previously installed conduit runs rather than laying their own individual conduit (substantial cost saving). Sharing is a common practice and understood, but until the researchers compiled data from all the disparate networks the extent of sharing was not known.
The final map contains: 273 nodes/cities, 2,411 links, and 542 conduits (with multiple tenants).
Prominent features of the map include:
•Dense deployments (e.g., the northeast and coastal areas)
•Long-haul hubs (e.g., Denver and Salt Lake City)
•Pronounced absence of infrastructure (e.g., the upper plains and four corners regions)
•Parallel deployments (e.g., Kansas City to Denver)
•Spurs (e.g., along northern routes)
Given the mission-critical operations that we are envisioning for the Shore, including emergency response as well as telemedicine, it is critical to determine whether the multiple service providers used to create network redundancy are sharing fiber optic conduit on any of the routes.
The map and related data can be found at the Department of Homeland Security’s PREDICT (Protected Repository for the Defense of Infrastructure Against Cyber Threats https://www.predict.org/Default.aspx?tabid=40&ctl=ViewFullNews&newsIndex=11&mid=871&selectmid=871) website (account required).