Main reason is that easy command easy to create station, easy to create call forwarding , if any error is there then we take trace also avaya support is very helpfull

Avaya has a good telephony solution BUT while Avaya is pushing customers to perform more upgrades/patching they have difficult to understand instructions with some of their platforms. In addition, when I've reached out to Avaya for support they seem to work harder at finding a reason not to provide support than actually solving the problem.