Hum, nobody has done an ansible tech write up, I have my own ideas about the ansible, ansible is approaching extreme relevance to the story...
WELP, time to actually do the thing!
The Ansible! Cornerstone of the Protectorate! Miracle of the BORG! Triumph of Humanity!
And an absolute little shit of a Prima Donna when it comes to mass data transfer, or multi-point communication. Yeah, doesn't come up much in common conversation, does it?
Truthfully, it hasn't come up much in practice either, with the Protectorate being as small as it is, but the ansible's limitations are plain to see for those who are aware enough to look.
But, maybe I'm dumping us at the deep end here. Let's start with the most basic point: the ansible itself.
The ansible is, for all it's importance and logistical power, actually fairly small. Generally a sphere roughly a foot in diameter, the ansible's shell is less a protective unit, and more a place to weld, strap, screw, nail, crimp, or otherwise afix the ansible in whatever desirable location one wants or needs.
The shape of the shell is also not a fixed value; that is to say, it need not be a sphere, but instead a cube, a polyhedron, some form of isomorph, a statue of the Liberator, and so on. The only things that MUST be consistent for the shell, is that it has sufficient space to house the internal components, and that it has exactly one in-port, and exactly one out-port.
Perhaps unsurprisingly, these two ports directly connect to the internal components of the ansible, which in turn can be divided into two sets; the in-set and the out-set. And at the core of these sets is, hmmm, let's stick with "core". Yes, an in-core, and an out-core. Of course these two cores don't actually care about each other, no, they only care about the out-core and in-core (respectively) of a completely separate ansible, wherever it happens to be in the galaxy.
Except, of course, (and this is where things become finicky) it ISN'T a "completely separate" ansible that our ansible connects to. In truth, there isn't such a thing as "an" ansible. Because ansibles always, ALWAYS, come as a pair. And these ansible pairs will NEVER communicate with any other ansible. If one part of the pair is destroyed, then the other is just as dead as it's twin.
So. Point-to-point communication, strictly and only. Already, this has dire, though not insurmountable, ramifications for wider implementation. Perhaps the easiest example would be in the case of fleet communications. Naturally, the Command ship of any given formation should have direct lines to each ship under it's flag. But should those ships, in turn, have direct lines to each other, or rely solely on a relay system, stringing multiple ansibles together, within the command ship? What of ships that were not part of the original formation? Should command ships carry multiple sets of extra ansibles for such occasions? How many? Should all command ships always have direct lines to each other, or again, simply relay through the ansibles of planetary commands? And what would that do to the ansible's load?
Hmm? What's an ansible's load? Well, I suppose I haven't explained that yet, have I? There are a few different ways to put it; throughput, bottleneck, capacity, limit, rate-of transfer, so on and so forth. The point being, although ansible pairs can move information between each other instantaneously, they can only move SO MUCH information instantly at a time. And while the amount it can move is more then sufficient to accommodate a fair number of holo-calls, it can begin to chug with even the most compressed blueprints and technical readouts the BORG can shove down it's throat. (Admittedly, they did try to transfer their entire library at once, but an entire day is an entire day, ya know?)
So, that's the two problems that really plague the ansible: they are VERY SPECIFIC where they send their transmissions (one-to-one, no negotiating) and have an inherent hard limit to how much data they can transfer in an arbitrary unit of time (those cores can only jiggle so much! Yes, they communicate in jiggles. Very complicated jiggles, but jiggles none the less.)
Now, the good news! Having foreseen these problems, the ansibles are relatively (*cough* super relative *cough*) easy to build, and can be easily networked together through a simple cogitator system. With these virtues combined, one can overcome the weaknesses of the ansibles with MORE ANSIBLES! So long as you don't mind hauling the ansibles however far they need to go, of course.
...Ah, I suppose that is the THIRD weakness of the ansibles, isn't it? Yes, you see, as noted before, ansibles always come in pairs. Two ansibles, which by their inherent nature, MUST be created in the same place at the same time, with no room to bargain. Like, literally the same room. Some of the smaller "manufactories" are basically oversized broom cupboards where apprentices do there graduation projects. Where was I?
Right, "always built as pairs". So, while instant transmission is miraculous, and technically faster then sound waves, keeping an ansible pair inside the same room is generally perceived as somewhat overkill when they could connect two planets on opposite sides of the galaxy.
But, and this is the tricky bit: one of those ansibles has to go to the other side of the galaxy. Like, physically. The long way. You can't cram an ansible through an ansible, especially if there isn't an ansible on the other end! And if either one of the pair breaks, express shipping might get you a replacement within the century. But the lack of guarantees makes that doubtful.
For a small polity, barely even started? Pffft, barely an inconvenience! Hardly any trouble at all! Part of the basic care package, even! For a massive, dilapidated, decentralized, hard headed, traditionalist, calcified, and generally very confused polity? They'll first have to figure out how you manage to fit the witch you need to power it in there. There might be some problems adopting the technology, is all I'm saying.
DONE!