Propose a solution for the WAN network infrastructure of a Courier service companys stations (all 16 branches and one headquarters are to be connected together). It is important to justify what you have proposed. Example of proposed solutions are (but not restricted to):

1. Networking devices (e.g. core router, L3 switch)
2. Connections (e.g. T1, X.25, ATM, SONET, MPLS)
3. Network services (e.g. 99.99% network connectivity, redundant connectivity, undisturbed high-speed access, traffic shaping, load balancing, backup sites)