Got a call from the HR for the initial interview set up. Manager and co-worker interviewed. Everything was technical question. Interview was very interesting indeed. Asked about sip, ISUP, IS41, Linux questions and also handoff question. Though they were happy with my technical knowledge, they were kind of disappointed when they learnt that I have kids and they said they needed some one who could work long hours. But somehow they came back to me with an offer after 2 weeks. May be because they couldn't get some one with good technical skill set and also who works long hours.