Depends on the area and location it's a good company, mostly due to the human factor. It's still is a corporate but open for changes at least in the CTO.
Cons
Bad bonuses, very bad HR (!) and you get kicked out once a project is done. period.
lots of free programs available i.e. weekly virtual yoga/cooking/personal finance/wellbeing classes
Cons
constantly under threat of layoffs, mostly contract work for other Telecommunications companies which are increasingly turning to competitors for opportunities