SDI Seminar

Speaker: Jose Carlos Brustoloni

Exposed Buffering and Sub-Datagram Flow Control for ATM LANs

Date: September 22, 1994

Abstract: We present the design and implementation of an ATM network interface incorporating two novel techniques to reduce end-to-end latency and network congestion while requiring little hardware support: exposed buffering and sub-datagram flow control. Applications using exposed buffering send or receive data from buffers shared with the network interface. Communication occurs with no latency due to copies or VM manipulations and no security breach. Sub-datagram flow control uses feedback from the receiver to pace transmission of the datagram in small bursts according to the bandwidth and buffering available and eventual loss detected. This enables higher-level protocols or applications to use large transmission units and better amortize per-packet protocol overheads even if switches have limited buffering and implement no flow control. We include results from our implementation using simple programmed I/O interface cards.