One certainty that all service providers except start-ups face is legacy infrastructure and so their performance and competitiveness can depend as much on how they cope with that as on their latest innovations. In fact, it can hinge on how well they marry emerging features with their legacy and ensure that as far as possible the latest enhancements are available to all customers and not just those that have been migrated to more advanced hybrid or IP based infrastructure. There is an important distinction to be made between legacy software and hardware, for the former can be much more of a hindrance to agility and ability to roll out new features quickly. This became evident a few years ago to…