1. A method for communication, comprising: coupling a host processor having a memory to communicate via a network interface device over a network on multiple, different connections, the network interface device comprising a context cache; storing respective context data for each of the connections in the memory; inputting from the host processor to the network interface device a sequence of work requests indicative of operations for data packet transmission to be carried out by the network interface device with respect to a plurality of the connections; looking ahead through the sequence in order to identify at least first and second operations that are to be carried out with respect to one of the connections in response to first and second work requests, respectively, wherein the second work request does not immediately follow the first work request in the sequence; loading the context data for the one of the connections from the memory into the context cache; and performing at least the first and second operations sequentially while the context data are held in the cache.