Vantaggi
For young engineers, you can learn a lot about technology. Barrier for entry in telecom is very high for startups. Therefore, this company will survive with its mediocre management and products, while selling competitor products. If you want to hide and do a 9 to 5 job with good benefits, you can do that here without much trouble. Heck you might even get promoted to a Manager, VP/GM, but you'll have to take your naps in meetings.
Svantaggi
Too much processes, I think even the US GOVT has less processes Team of B Grade management at best. Management likes to keep status quo by not hiring and promoting people that are better and smarter. A players leave and join other Silicon Valley companies. New managers quit within months after realizing change needs getting rid of the whole management structure and dead weight. There are people managers and technical managers and managers of all sorts