Pros
Working with great colleague's and in a relaxed atmosphere. It was a great place to learn about networking, hardware and then how service provision works in the real world. I came in as a tier 1 engineer and worked my way up, so there is definitely opportunities to progress up the ladder if you work hard. You get to know customers and their networks quite well, so its easy to feel attached to your work you do. Working hard can be the difference between an unhappy or a happy customer, so your effort can make a direct difference to how well the company does. They help you develop by paying for exams and training.
Cons
Staff turnover was high at times so it was easy lack motivation when you see people leave really soon. A lot of expectation can be put on you at times to deliver things quickly without adequate planning.