Wormhole IP over (connectionless) ATM

Abstract

Abstract--High-speed switches and routers internally operate using fixed-size cells or segments; variable-size packets are segmented and later reassembled. Connectionless ATM was proposed to quickly carry IP packets segmented into cells (AAL5) using a number of hardware-managed ATM VCs. We show that this is analogous to wormhole routing. We modify this architecture to make it applicable to existing ATM equipment: we propose a low-cost, single-input, single-output Wormhole IP Router that functions as a VP/VC translation filter between ATM subnetworks. When compared to IP routers, the proposed architecture features simpler hardware and lower latency. When compared to software-based IP-over-ATM techniques, the new architecture avoids the overheads of a large number of labels, or the delays of establishing new flows in software after the first few packets have suffered considerable latencies. We simulated a wormhole IP routing filter, showing that a few tens of hardware-managed VCs per outgoing VP usually suffice. We built and successfully tested a prototype, operating at 2 x 155 Mb/s, using one field programmable gate array (FPGA) and DRAM. Simple analysis shows that operation at 10 Gb/s and beyond is feasible today.Index Terms--Connectionless ATM, gigabit router, IP over ATM, routing filter, wormhole IP, wormhole routing.

"Tráfego multimídia com QoS em redes deflexivas e redes híbridas:simulação e implementação"

“…A especificação do padrão ATM foi tão ampla que permitiria sua utilização nos três domínios de rede: LAN, MAN e WAN. De fato, no meio da década de 90 mui-tos backbones foram sendo amplamente substituídos e expandidos com a utilização de equipamentos ATM [72], pois além desta ser vista como a tecnologia do futuro, também possuía grande largura de banda e escalabilidade. Infelizmente o ATM não teve o mesmo sucesso no desktop, apesar de haver soluções para emulação de redes locais baseadas em Ethernet ou Token Ring que mantinha compatibilidade com o protocolo IP.…”