  A current trend in networking and cloud computing is to provide compute
resources at widely dispersed places; this is exemplified by developments such
as Network Function Virtualisation. This paves the way for wide-area service
deployments with improved service quality: e.g, a nearby server can reduce the
user-perceived response times. But always using the nearest server can be a bad
decision if that server is already highly utilised. This paper formalises the
two related problems of allocating resources at different locations and
assigning users to them with the goal of minimising the response times for a
given number of resources to use -- a non-linear capacitated facility location
problem with integrated queuing systems. To efficiently handle the
non-linearity, we introduce five linear problem approximations and adapt the
currently best heuristic for a similar problem to our scenario. All six
approaches are compared in experiments for solution quality and solving time.
Surprisingly, our best optimisation formulation outperforms the heuristic in
both time and quality. Additionally, we evaluate the influence ot resource
distributions in the network on the response time: Cut by half for some
configurations. The presented formulations are applicable to a broader
optimisation domain.
