Early selective packet discard for alternating resource access of TCP over ATM-UBR

K. Cheon, S.S. Panwar
Proceedings of 22nd Annual Conference on Local Computer Networks  
We investigate packet discarding schemes for TCP over ATM with UBR service. In doing so, we tested the e ective throughput of two existing schemes, Partial Packet DiscardPPD and Early Packet Dis-cardEPD, as compared to the Random Cell Dis-cardRCD scheme which discards any incoming cells after bu er over ow. We observed that PPD alleviates the e ect of packet fragmentation so that it gets e ective throughput enhancement over RCD, and EPD provides further enhancement over PPD. After closer
more » ... After closer investigation, we found that there is a sustained congestion problem other than packet fragmentation that causes the e ective throughput to be degraded. We noted that sustained congestion resulted in the synchronization of TCP window expansion and shrinkage. To p r ovide a solution for this problem, we propose the Early Selective Packet DiscardESPD policy, a strategy which makes sessions take turns in accessing network capacity by discarding packets from selected sessions rather than randomly. Our results shows that ESPD achieves throughput and fairness enhancement over EPD with only a modest increase in implementation complexity.
doi:10.1109/lcn.1997.631000 dblp:conf/lcn/CheonP97 fatcat:2yyrf3abyrh5hjdyvk4dpbdtvu