For your information of how long light takes to reach each of planets in Sol from Sun.

Source: http://image.gsfc.nasa.gov/poetry/venus/q89.html

Communications in Two Clusters divided into two major sections.

The first was the regular radio communication which was the most common method for civilians to communicate. While regular radio communication was regulated, it was regulated lightly as the navy almost exclusively used FTL communication.
However, regular radio communication was feasible only for Earth and Moon communications as the latency was too high for interplanetary calls. Still, regular video communications for Earth to Venus, and Earth to Mars were used due to tolerant latency.

The second was FTL (Faster Than Light) communication. FTL comm. required specialized comm. beacons to receive and accelerate electrons via particle accelerators in order to achieve faster than light speed. At the beginning of Two Clusters, year 9599, FTL beacons were able to achieve 20x of light speed.

Below chart is the time a boosted electron to reach planets from Sun.

FTL beacons resembled a large soccer-sized golf ball with tens of antennae installed on surface with each hole being a single particle accelerator. The roles of FTL beacons were to receive, accelerate/boost, and redirect signals to a designated arc.

Even with this technology, latency was still an issue for long distance communications such as Earth to Uranus as it took 450 seconds for a signal packet to travel. And combined with network overheads, realistic latency between Earth and Uranus became approximately 600 seconds.

However, once a communication channel was established, it was possible to send signal packets simultaneously and continuously from both sides at the same time. In addition, the FTL beacons were able to optimize paths once a channel was utilized for a while, thus further decreasing network overhead.

The end result was that realistic latency became approximately 500 seconds from Earth to Uranus which was still a lot of latency but workable.

FTL communication required an extremely well-established beacon networks in order to maintain acceleration and optimization. The main application for FTL communication was video / audio calls between planets of great distances where normal electrons resulted too much latency. For regular civilians, it was fairly expensive to make calls via FTL comm. and therefore, e-mails were used most of time if the distance is too far.

FTL beacon ownerships

FTL beacons were important assets to everyone. While they were inexpensive to produce, replacing them costs considerable amount of time. Therefore, FTL beacon ownership was taken seriously and any actions that damage the beacons were responded with lethal forces.
While each planet or space station/outpost were responsible for maintaining the beacons within their own boundaries, the ownerships differed.

In Sol system, all FTL beacons belonged to United Sol. United Sol also maintained some FTL beacons right outside of Sol system.

In Andromeda cluster, Andromeda council maintained ownerships of FTL beacons.

For the neutral zone between Sol system and Andromeda cluster, Freedom colony was in charge of maintaining FTL beacons but number of FTL beacons in this zone was scarce due to the immense area they needed to cover.

eFTL technology (Enhanced Faster-Than-Light) & technological limit

eFTL tech was developed to increase the acceleration even further. This technology was developed in later 99xx and boosted the speed to 22x of light speed. However, in doing so, they ran into the ultimate limitation of this technology. When an electron exceeded 22 times of light speed, the electron shattered, literally becoming nothingness. Therefore, eFTL was the last line of this technology.