Sounds to me you've not worked on UCM recently, if it all.
Call Forward No Coverage.
LCR (from the very beginning):
1. Create a Route Group containing the gateway or trunk device for the site you are configuring LCR
2. Create a Route List containing the previously created Route Group
3. Create a Route Pattern for the LCR pointing to the Route List previously created
Cisco's Unified Communications Manager platform is extraordinarily well built once you move past version 7.1.3 (6 was a solid, but 7 introduced logical routing and other important features). Yes it is expensive. But it is robust, stable and the pool of knowledgable engineers can't be denied; if you don't understand the immediate value of that I've wasted your time and mine. Lastly, before I end this rant, one word: support. Who do you call for support at 10pm for your Asterix box? Sure, some companies provide support, but not on the same level Cisco can provide.
plus net outages don't make a satellite office useless unlike a centralized Cisco setup.
I am now certain you either have no experience with Cisco's UC platform or simply live with your head in the sand. The technology is called Survivable Remote Site Telephony (SRST).
Comparing Asterix to Cisco's UCM is disingenuous as they have entirely different markets with different requirements.
The simple fact of the matter is you don't deploy Asterix if you can afford UCM (if you can afford it, you're likely large enough to benefit from it).
So, to recap:
-Enterprises need support. They need it yesterday when problems arise.
-Knowledgable engineers to support and maintain the solution.
-UCM was built to scale. I'm talking 300 sites, 150,000 end points, 12 call processing agents (termed Super Cluster when you have more than 8), numerous MoH/TFTP servers and the like. This is easily possible with CUCM, and it's extremely stable.
-The platform is easily extended to Presence, WebEx, Contact Centers, Attendant Consoles, and numerous 3rd party applications.
-Cisco has another advantage which no other company in the world can claim: They own the network. That means a fully integrated solution, from the switch to the handset, and the numerous benefits that entails.
An aside, of the clients I have personally migrated from Asterix (of which there are 4), none had more than 5,000 end points.
Please acquire some perspective before you go around baselessly besmirch the big bad corporation and their products, and please don't try to make an argument about the feature set differences. That's never the deciding factor with these two products.
P.S: the virtual person you describe is available as a 3rd party solution.
Well, that turned out longer than I intended; apologies, as I could keep going on and on about this subject.