I'm currently helping build out a new office and trying to find the best router for the job. My main concern is ensuring it can handle the WAN line(s) we have coming in. When I looked at the 2921 series it seems to have a throughput max of 75Mbps and with our lines totalling 800Mbps I'm wondering how 'big' of a router we'll need.
Here's some of the details that should give a rough idea of our needs. Our requirements are pretty basic at the moment but we would like to start to build our a reliable network infra as we're quiclkly expanding the business (20 -> 60 employees in 6mo thus far)
300Mbps 1:1 - BT Fibre
100Mbps 1:1 - Virgin
100 person max office size
2-3 VPNs into datacentre's
eventual deployment of our own VoIP network (currently managed by buildings VoIP)