Communication Profile

JAS Efficient Exchange Protocol


The JAS Efficient Exchange Protocol (JEEP) is a best-effort packet transmission protocol that can be used to send messages between applications over a SpaceWire data link. JEEP is similar to the JRDDP protocol in that provides a segmentation capability to promote fairness between all applications needing to communicate on the network, the ability to send multiple types of data across a SpaceWire network, and a field to specify the data contents that are being communicated. This allows any type of application specific data to be transported with JEEP.

The only difference between JRDDP and JEEP is that it does not include the ability to automatically retransmit lost or corrupt data. This makes it a more efficient protocol from a performance standpoint because it eliminates the need to check for errors and send acknowledgement packets.

The JEEP protocol consists of two TEPs, a sender and a receiver. The sender accepts data from a user application, segments it into smaller pieces in accordance with the MTU of SpaceWire, packetizes it for transmission, and then sends it over the data link. There are no checks performed by the receiver to ensure the data was received in order or without error. This is the responsibility of the application receiving the data.

JEEP is defined in more detail in the Communication Specification.