A method in a network node that includes a host and an accelerator, includes holding a work queue that stores work elements, a notifications queue that stores notifications of the work elements, and control indices for adding and removing the work elements and the notifications to and from the work queue and the notifications queue, respectively. The notifications queue resides on the accelerator, and at least some of the control indices reside on the host. Messages are exchanged between a network and the network node using the work queue, the notifications queue and the control indices.