Communication and networks exercise: multimedia (VoIP, RTC, FEC)

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Hello. I am in need of help with this exercise; that is I need answers to the questions. I messed up and didn’t see exercise before 20 minutes ago, and the deadline is in 1 hour 30 minutes. I need answers to the questions, but I dont need an illustration on the “make an illustration” questions. I can make those myself, but it would be nice with some notes on how it should be constructed, or a quick draft (but not a must!). I have uploaded two pages from the textbook about skype (referenced in exercise).

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In this exercise, you will study a Voice-over-IP (VoIP) application. The application is similar to the example in chapter 9.3 in 7th edition (7.3 in 6th edition). Even though many VoIP applications like Skype no longer provide host-to-host services, this exercise helps generate a general understanding of different concepts in multimedia networking. The goal is to learn about packet loss, loss recovery schemes, delay, jitter and RTP. To pass this exercise, you are expected to show an understanding of the concepts and theory of VoIP by answering the questions. Simple, numerical answers will not be accepted on their own.

In this application, the sender uses normal RTP and transmits G.722-encoded voice at 48 Kbps. The application collects encoded data in 16 millisecond chunks.

Question 1. What is the rate at which data is generated at the sender (in bytes)?

Question 2. What is the size of the IP datagrams sent? You must clearly show the steps in how you calculated your answer and what elements the datagram consists of.

Question 3. Explain how an arbitrary RTP packet in the application will look like. Use actual values from the application when possible. Include the size of the fields and elements of the packet.

Loss recovery schemes can be used to preserve acceptable audio quality in the presence of packet loss. We will focus on three types of loss anticipation schemes: forward error correction (FEC) with redundant encoded chunks, FEC with redundant lower-resolution audio stream, and interleaving.

Question 4. For each of the three schemes listed in the previous paragraph, show how much additional bandwidth each of them require of our application. For the first type of FEC, suppose a redundant chunk is generated for every five original chunks. For the other type, suppose GSM is used for the low-bit rate encoded stream. For each scheme, include both the new transmission rate and the percentage increase

Question 5. For each of the three schemes, explain what happens if the first packet is lost in every group of five packets. Which scheme will have the better audio quality?

Question 7. For each of the three schemes, explain what happens if the first packet is lost in every group of two packets. Which scheme will have the better audio quality?

Question 8. Make an illustration of the scenario in question 7 for FEC with redundant lowerresolution audio stream. The figure should be made such that it’s clear that the student understands how the scheme works

Question 9. For each of the FEC schemes, how much playback delay does each scheme add? What can be said about the delay of the interleaving scheme?

Sample Solution

Weatherford Laboratories are involved in rock and fluid analysis by providing several services related to oil and gas production around the world. Weatherford labs has wide experience in working with different type of fluids and reservoir which play an important role for oil and gas producers. In addition, this experience leads the company to reach determinations on the best production for the long-term viability of a well.
Weatherford labs provide several services according to the client requirements, for instance MICP (Mercury injection and Capillary pressure), Porosity and Permeability measurement, CT scan for cores, Soxhlet Cleaning, Core photo, Core gamma, Fluid Saturation by Dean Stark, Salinity Analysis, and finally Miscible Extraction.
Weatherford laboratory sections

The Waterford lab in Oman is divided into several sections and each department has special tasks. The flow chart below shows the different sect
The Conventional core analysis department is about using different instrument in order to measure the porosity and permeability of fluids using Nitrogen and Helium gases. In addition porosity and permeability are important factors in petroleum.
This section provide an important data related to porosity and permeability in order to get a better understanding in reservoir and flow of different types of fluids using DHP (Digital Helium Porosimeter) and DGP (Digital Gas Porosimeter) devices also VINCI is one of the instruments that used for steady- state processes.
SCAL sectio
Special core analysis section are specialist in understanding petrophysical properties goes beyond special techniques with advance tests to help the client more in estimating their fields.
It is important to note however, that SCAl provide several services in MICP (mercury injection and capillary pressure), FRF (formation resistivity factor), and permeability of fluids especially water, CT scan, and flush cleaning using different solvents.
However, the department provides unique tests related to the above processes in order to ensure the delivery of good quality services and focus on saving costs to the customer.
Therefore, SCAL section is responsible for different fluid analysis at several stages in order to fulfil all the operational requirements and to achieve important results that optimize production and development of the fields.

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