A method for sending data over a network from a host computer. The host computer includes an operating system comprising at least a user space and a kernel space. The amount of data provided from the user space to the kernel space within one system call exceeds the size of an IP packet. A loop function in an application in the user space sends multiple packets to the kernel space within a single system call containing IO vectors which contain pointers to the data in the user space. A last data unit being processed may be designated using a flag included in the message header. In the kernel space a second loop function is used to reassemble the vector groups and pass them down the network stack. The data may then be passed to the network hardware using a direct memory access transfer directly from the user space to the network hardware.