These are my ex-hombres; I was their Service & Ops Mgr from 2011-15.
In essence Charter is a major player in unified communications although the Voice piece is virtually non-existent today so about 99% of their expertise lies in data comms, aka network routing/switching/monitoring. They do it all from design, builds, maintenance and support. A major Canadian partner with Cisco, Juniper and Avaya among many other vendors. Very low key, below the horizon profile and by design.
This is the outfit that bought out Boardwalk Communications in 2016; they have about 100 staff from Victoria to Toronto with major hubs in Vancouver and Calgary. Not sure about this HQ though as that picture was first posted on the site over a year ago. Haven't been out there lately so no idea if there has been any progress on this building.