DESIGN, IMPLEMENTATION, AND PERFORMANCE-MEASUREMENT OF A NATIVE-MODE ATM TRANSPORT LAYER (EXTENDED VERSION)

We describe the design, implementation, and performance measurement of a transport layer targeted specifically for asynchronous transfer mod e (ATM) networks, The layer has been built from scratch to minimize ov erhead in the critical path, provide per-virtual circuit quality of se rvice (QoS) guarantees, and take advantage of ATM adaptation layer 5 f unctionality, It provides reliable and unreliable data delivery with a choice of feedback and leaky-bucket how control, These services can b e combined to create per-virtual-circuit customized transport services , Our work is novel in that it provides high-performance, reliable, fl ow-controlled transport service using cheap personal computers (PC's). We describe the mechanisms and the operating system support needed to provide these services in detail, An extensive performance measuremen t allows us to pinpoint and eliminate inefficiencies in our implementa tion. With this tuning, we are able to achieve a user-to-user throughp ut of 55 Mb/s between two 66 MHz Intel 80486 personal computers with F ORE Systems' HPA-200 EISA-bus host adaptors, The user-to-user latency for small messages is around 720 mu s. These figures compare favorably with the performance of far more expensive workstations and validate the correctness of our design choices.