In a VoIP network, Host A converts analogue voice to a digital 64 kbsp bit strea
ID: 3798588 • Letter: I
Question
In a VoIP network, Host A converts analogue voice to a digital 64 kbsp bit stream on the fly. Host A then groups a bits onto a 48-byte packets. There is only one 1 Mbps link between the two hosts and it has a propagation delay of 2 ms. As soon as Host A gathers a packet it send it to Host B and as soon as Host B gets an entire packet, it converts the packet's bit back to analogue voice. What is the total delay between the time a bit is created at Host A and the time that bit is decoded (converted back to voice) at Host B?Explanation / Answer
The host A transmits bits in a group of 48 byte packet
48 byte= 384 bits.
Before the first bit of a packet can be transmitted, all the other bits belonging to the same packet need to be generated. This requires: 384 / 64x10^3 = 6 ms
The time to transmit this packet is: 384 / 10^6 = 0.384 ms
The propagation delay = 2 ms
Therefore, the delay until decoding is: 6ms + 0.384ms + 2ms = 8.384 ms