Stability degree of switches with finite buffers and non-negligible round-trip time

We answer the question on how much memory a packet switch/router needs; more specifically, we propose a systematic method that is simple, rigorous and general for determining the absolute lower bound of packet buffering required by practical switching systems. Accordingly, we introduce a deterministic traffic scenario that stresses the global stability property of finite output queues and demonstrate its usefulness by dimensioning the internal buffer capacity of two popular CIOQ switches.