1. [Publications](/publications) 2. Light-Weight Protocols for Wire-Speed Ordering # Light-Weight Protocols for Wire-Speed Ordering ![](/sites/default/files/styles/wide/public/pubs/2018-11_Light-Weight-Protocols-for/default.jpg?itok=Dt7fpMLR) We describe light-weight protocols for selective packet ordering in out-of-order networks that carry memory traffic. The protocols are designed for heterogeneous high-performance systems, in particular, accelerated systems with endpoints that have few resources available for interfacing the network. The protocols preserve the semantics of a relaxed memory ordering model as adopted by highly-threaded many-core processors and accelerators. The protocols achieve link-rate performance through the following techniques: (1) speculative connection setup avoids round-trip delays found in protocols with little knowledge about endpoint resources, (2) target-side ordering avoids round-trip delays found in source-side ordering mechanisms, (3) fine-grained ordering removes dependencies unwarranted by program code avoiding cumulative ordering dependencies caused by coarse-grained ordering, (4) ordering relaxations and optimizations for producer/consumer communication patterns. We describe two ordering protocols that provide (1) strict sequential ordering and (2) relaxed ordering for multi-packet transfers. The protocols impose no restrictions on routing, including multipath routing. ## Authors [Hans Eberle](/person/hans-eberle) [Larry Dennison](/person/larry-dennison) ## Publication Date Tuesday, November 27, 2018 ## Published in [Proceedings of the 30th International Conference for High Performance Computing…](https://sc18.supercomputing.org) ## Research Area [Networking](/research-area/networking) ## Copyright This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to .