{"id":33,"date":"2012-10-09T08:05:08","date_gmt":"2012-10-09T08:05:08","guid":{"rendered":"http:\/\/concentus.co.nz\/?p=33"},"modified":"2012-11-26T08:55:15","modified_gmt":"2012-11-26T08:55:15","slug":"an-introduction-to-mesh-networks","status":"publish","type":"post","link":"https:\/\/concentus.co.nz\/?p=33","title":{"rendered":"An Introduction to Mesh Networks"},"content":{"rendered":"

What’s wrong with the Internet?\u00a0 Nothing really, if you are prepared to put up with its inherent unreliability and intrinsic vulnerabilities.<\/p>\n

The Internet cannot be relied on if you need continuous secure communication between two end-points at a distance.\u00a0 The greater the distance, the greater the vulnerability and unreliability.\u00a0 The more important the communication line, the more important it is to protect it from attack.<\/p>\n

The conventional Internet, designed originally by DARPA to survive even a nuclear assault is strangely susceptible to deceptively simple attacks.\u00a0 Routers can go down, name servers can be commandeered and corrupted, intervening high-level pipes can be tapped and data duplicated and stolen, addresses can be DOS’ed.<\/p>\n

The source of the Internet’s vulnerability is its reliance on centralisation<\/em> and authority<\/em>.\u00a0 “Centralisation” refers to the manner in which communication channels are centrally allocated, controlled, and aggregated upward, along major channels, and through routers.\u00a0 “Authority” refers to the notion that the network users must trust that the network is kept secure and integral by the power of authorities which manage and maintain it.\u00a0 These vulnerabilities turn out to be severe, and relatively easily exploited.\u00a0 The key to addressing these vulnerabilities lies in bypassing them and engineering them out of the system.\u00a0 This is done by introducing principled de-centralisation\u00a0 and redundancy.<\/p>\n

One way to do this is through “Mesh Networking”. \u00a0 “Mesh Networking” is a type of network topology<\/a> that enables highly reliable, highly secure communications outside of the normal Internet architecture.\u00a0 It is completely de-centralised, and does not rely on any governing authority.<\/p>\n

Mesh networking works by creating a large set of highly redundant pathways in a “mesh”.\u00a0 Whereas in the Internet network, each device must connect with a delegated superior device, in a mesh network each device on the network can communicate with any other immediately accessible device.\u00a0 With only a few exceptions, an Internet device generally has only one path to its destination.\u00a0 A Mesh device however has multiple ways of connecting with other devices near to it.\u00a0 Because all devices in the mesh have multiple paths, with each additional device, the number of possible paths increases exponentially.\u00a0 In a rich, defuse network, it is nearly impossible to interpose a blockage or remove a critical link.\u00a0 The endpoints themselves must be completely surrounded and blocked, something that is ordinarily impossible.<\/p>\n

Mesh devices are usually located in relatively close physical proximity.\u00a0 Communication may be by fixed line, but more often they are connected by radio communications protocols, such as WiFi.\u00a0 In a conventional setting, a single mesh device, such as a laptop, would sense what mesh-enabled devices were nearby, and open channels to all of them.\u00a0 When it wanted to communicate to a particular device, it would broadcast a message to all devices, asking if they knew where this device was.\u00a0 The broadcast request is then propogated throughout the entire mesh, like the vibrations on a spider’s web, till the target endpoint eventually received the communication packet.\u00a0 The path that packet took, from source to destination then becomes a potential path.\u00a0 All potential paths then find their way to the endpoints, which select the shortest operational path, and use that.\u00a0 Secure communication between endpoints would then be negotiated using a form of encrypted communications over TCP (without IP, the Internet Protocol).\u00a0 If at any time the path becomes blocked, the process is repeated, and a new path is found.\u00a0 Network flooding by broadcast messages is limited by relatively sophisticated algorithms which prevent echoing and reechoing of requests to infinity.\u00a0 Devices can cache paths or path segments used repeatedly. Objects which cannot be found within a certain number of “hops” are deemed to be unreachable.\u00a0 In a mobile context, additional complexities exist as devices move between radio towers, but these are solvable.<\/p>\n

It will be readily apparent that such a network is highly secure.\u00a0 Because it does not use fixed, predictable paths, the most common types of surveillance, involving a “man in the middle” approach becomes extremely difficult and uncertain.\u00a0 For instance, the Great Firewall of China, relying on spying on ISP’s could not work, as quite simply, there would be no ISP’s or other central authorities.\u00a0 No communications takes place except between devices on the path as determined in real-time each time a new path is needed between two endpoints.\u00a0 With web-type traffic, every request to a new domain would require a new path.<\/p>\n

Novel as they may seem, Mesh Networks have been studied with increasing interest for nearly a decade.\u00a0 When I first contemplated the problem of Internet Network centrality in 2004, my first-cut solution was a Line-of-sight Infrared Laser Mesh Network, which I abandoned because it seemed impractical.\u00a0 Soon after this however, WiFi networks became cheap enough and powerful enough to make them practical in meshes.\u00a0 However, it soon became obvious that WiFi would have to become vastly cheaper than it was even five years ago if Mesh Networks were to be useable.\u00a0 Given the fascinating problems involved, papers began to appear, discussing many aspects of mesh topology and network behavior.[1]<\/p>\n

In the eight years since I first became interested in them, a lot of progress has been made. A major Open Source project, indeed, an entire community has sprung up around the\u00a0 notion of Mesh Networks.\u00a0 Perhaps the most well-known is “Project MeshNet”<\/a>.<\/p>\n

Project Meshnet provides a portal to a number of projects related to the provisioning of mesh networks. Besides a slick animation, the project has a number of deliverables in varying stages of completion, including;<\/p>\n