Stable salary.
Managers are open to discuss salary increase.
Ability to switch between specialties (e.g. QA -> TA -> Java Software Developer).
Easy grow.
Cons
Not about technologies, lot of boilerplate Java legacy (xml hell, but I dunno about other telecom companies).
No rockstars.
Easy grow - seen "Senior QA" who doesn't know how to create a dashboard in Jira.