port unreachable packet

This paper studies an improved E-pathchar bandwidth estimation model, which is calculated through delay. The kind of return packet of a port unreachable packet, which is fixation length and small transmit delay, is selected.
研究了一种通过测量时延值进而估算各段带宽的改进E-pathchar带宽模型,并给出了具体的测量与实现策略,时延测量中返回报文选用了大小固定、传输时延小的差错报文。