# 傳輸延遲計算~~~!!奉上20點

assume a propagation speed of 50 km/hour.

a. Suppose the caravan travels 150 km, beginning in front of one tollbooth, passing through a second tollbooth, and finishing just before a third tollbooth. What is the end-to-end delay?

b. Repeat(a), now assuming that there are five cars in the caravan instead of ten.

we consider sending real-time voice from Host A to Host B over a packet-switched network(VoIP). Host A converts analog voice to a digital 64 kbps bit stream on the fly. Host A then groups the bits into 56-byte packets. There is one link between Host A and B; its transmission rate is 500 kbps and its propagation delay is 2 msec. As soon as Host A gathers a packet, it sends it to Host B. As soon as Host B receives an entire packet, it converts the packet’s bits to an analog signal. How much time elapses from the time a bit is created(from the original analog signal at Host A) until the bit is decoded (as part of the analog signal at Host B)?

### 1 個解答

• 9 年前
最佳解答

1. Assuming that there is not delay at tollbooths and the bandwidth between the tollbooths is infinite:

1a - 3 hours

1b - 3 hours

2. end to end delays = 2msec + 112/125 msec + 7msec

2012-03-21 20:21:44 補充：

又不是神定理,那有神公式啊?

觀察一下妳就可以看出來的

妳試一試 看不出我再告訴妳!