Here is my working paper (pdf) for Innocenti on children's experiences of school in Dhaka. I interviewed teenagers from middle-class families and from slum areas to try and understand whether there were processes within the school that disadvantaged children from poorer backgrounds (in addition to processes outside the school). However, I couldn't find many children who were from radically different backgrounds yet in the same school. In other words, sorting between schools - and at the secondary level, this mostly means different types of private school - is so strong that it's hard to determine whether what happens /within/ schools also reproduces educational inequality. And there were some surprising similarities across different backgrounds; for instance, the experience of violence within and outside school was quite common. Nevertheless, it was clear that the middle class teenagers interviewed here had a lot more options when things went wrong and a sense of inevitability of reaching college; while those from slums were in a much more precarious position.
Parents from both types of background were paying substantial amounts both for private school fees, even while they often questioned the quality, and for private tuition, especially in the run-up to important exams. In many ways the dreams of private-schools-for-the-poor advocates have already come true in Dhaka (at the secondary level, anyway), and it doesn't work out particularly well for anyone (except possibly the richest, who were not included in this study).