In Grizzly we took a significant step forward with defining a network service and incorporating one service insertion model in the form of 'routed-service-insertion'. The proposed session aims to revisit this topic to move the discussion forward with exploring use cases requiring other modes of L2/L3 service insertion. The other complementary aspect of this discussion is services' chaining and possibly the requirement for steering. Currently there is one service defined and implemented in OpenStack Networking in the form of Loadbalancer, but more services such as Firewalls will also need to be added. With the possibility of more than one service it becomes relevant to explore the model of how multiple services can be requested and sequenced.