Other than the FTL squirt routers integrated into the stargates themselves, the most important parts of the interstellar communications infrastructure – and before it the interplanetary communications infrastructure – are each system’s relay stations.

Customarily located above and below the acme and nadir poles of the system’s primary star, relays are statites, hanging in position from and stabilized by variable-geometry solar sails. This positioning at a sufficient distance above and below the ecliptic gives them the best possible line of sight on every object on the system: stargates, planetary geostat constellations, major drifts, and starships operating in the normal (i.e., along the ecliptic) traffic lanes, with the minor exception of the most epistellar of planets, coronal habitats, and other sun-hugging operations.

While for the most part, intra-system networking is done using standard mesh protocols, coordinated via shortest-link routing protocols based on current light-lag, occultation ephemerides, and traffic-control data, the relay stations’ positioning enables them to serve as the route of last resort for all backbone traffic in the system. In particular, they handle traffic between planets and drifts currently on opposite sides of the primary, and interstellar traffic without an endpoint in the system; i.e., stargate-to-stargate traffic. In these functions, both relays function as load-balanced peers, although scaled such that each is capable of handling the total expected load alone if necessary.

The relay stations also function as management points for the interplanetary mesh, and as such at least one is continuously manned by a site systems administrator, usually an infomorph.

– IIP Elucidated, Volume I: Perspectives