Ghostnet

Alongside the worldnets, Ghostnet mirrors are the second major component of a world's data communications infrastructure.

History

When the ansible was first created, it was unreliable, slow and expensive. This was a problem for businessmen who wished to invest in companies off-world, and even more so as the growing fleet of temple ships made interplanetary commerce more feasible. While a worldnet could be relied on to provide information about companies on your own planet, any external data would be difficult to obtain without sending couriers to collect information from another planet's media.

Before long, this situation led to businessmen and executives making up a growing portion of passengers on temple ships. However, these are precisely the customers who would not want to be out of touch for the duration of a voyage.

It was not long before entrepreneur Jaime Tyson set up the Network Ghost Corporation. This involved a freighter loaded with server equipment coming onboard a temple ship, and providing a wireless data service to those in nearby passenger areas. Before boarding, the ship would be connected to a dedicated data terminal on a line station, and spend several hours receiving a cached copy of a large portion of the planet's worldnet. This meant that while in-flight, passengers on board a temple ship would have access to most of the worldnet of the planet from which they had departed. Although this cached data often quickly became stale, it was better than being entirely out of touch and NGC quickly began to turn an astonishing level of profit.

In 884, the running of these caches was turned over to the church. With the additional funding and privileges this gave, each temple ship could now have a near complete copy of the worldnets of the planets it had recently visited. Two years later, in protest over a sudden price increase by Interspace Messenger Corp, the cacheing was made a bidirectional process, and the modern Ghostnet Mirror was born.

Current Architecture

Every world at class 3 or above, and many class 2 planets, now has a number of dedicated facilities known as Mirrors. These are each assigned a specific part of the worldnet's namespace, which they monitor for changes in an attempt to keep as recent a cache as possible. When a temple ship goes into orbit, these caches are then transmitted in parallel using an array of high-frequency communication lasers. This transmission is known as an upstream.

The number of mirrors will depend on the size of the worldnet, and is normally sufficient to upstream an entire cache of the worldnet in the time the temple takes to load its physical cargo. This means that the temple's onboard network has a cache of the worldnets of the last dozen planets visited.

In addition, there is a corresponding downstream sent to each mirror in the same way. This gives the mirrors a cached copy of the worldnets of other planets, which can be used to provide a cheap alternative for citizens who wish to browse off-planet information. It is this cache which is known as a planet's Ghostnet. On more advanced worlds, a mirror may also select the most important nodes from a downstream, and include these in the next upstream to a temple which doesn't already have them. In this way, data of high importance to users throughout the universe is carried on all temple ships, rather than those which have recently visited the world where the data oriinated.

Multimirrors

A small number of mirrors, mostly owned by corporations rather than the church itself, have the additional task of synchronising a local worldnet node with its ghostnet counterparts. So if a company owns sites on multiple worldnets, any change applied to one version is propagated to others when the ghostnets of its partner worlds receive the updated copy. These nodes are known as multi-homed, while the mirrors that facilitate them are known as multimirrors, after the original software developed by the Free Enterprise Corp. In fact, most multimirrors still run Enterprise Multimirror 2.2, despite the existence of several widely-known security flaws. (see Gates)