With NJE, JES2 can transmit a job intended to execute at another node directly to that node. If intermediate nodes are present, JES2 receives, spools, and retransmits the job through each of these. NJE handles job transmission on a store-and-forward basis. That is, a node must completely receive a job before it can take any action to either execute the job or transmit the job to another node. When the receiving node has completely received and spooled the job, the transmitting node frees the resources that it allocated to transmit the job.

JES2 can send both job and SYSOUT output data sets through a series of devices called transmitters, which select files destined for nodes reachable through the NJE line to which these transmitters are assigned. Job and SYSOUT transmitters select files from the transmission ($XMIT) and Network queues respectively, which are ordered FIFO (first-in-first-out) within priority. There can be multiple transmitters (and receivers) on a line as defined on the NJEDEF or LINE initialization statements. For recommendations on how to specify transmitters and receivers in your initialization stream, see Specifying transmitters and receivers.

SYSOUT files can range in size from very small (for example, one record, such as a Netmail acknowledgment) to very large (millions of records). When a transmitter has selected a file, it will not interleave it with other files or voluntarily interrupt the transmission until that file is completely transmitted. If the line drops or the transmission is otherwise interrupted, the entire file must be re-transmitted from the beginning. For recommendations on how to set up transmitters to send SYSOUT files, see Specifying work selection values for NJE transmitters.

Figure 1. Processing Flow Through a Network