CS305 Computer Networks Project:
Remote Meeting
Introduction
Video meetings have become essential in today’s digital landscape, transforming how people
connect, collaborate, and communicate. With the rise of remote work, online learning, and global
partnerships, video meeting allows individuals and teams to interact across vast distances,
fostering real-time collaboration without the need for physical presence. The implementation of a
video meeting project relies heavily on core computer networking principles and protocols,
making it an ideal opportunity to consolidate and apply the knowledge gained throughout the
course. 
Requirements
In this project, you are required to construct a simple video meeting system in Python that
enables participants to communicate over the network using video, audio, and text in real time.
This project emphasizes building network frameworks and utilizing network protocols. The system
framework is divided into two parts: Client-Server (CS) and Peer-to-Peer (P2P). Implementing the
system with the CS framework forms the basis component, while implementing it with the P2P
framework is an optional bonus (details provided later). Meanwhile, a video meeting system relies
on several key network protocols that enable real-time audio, video, and text communication,
such as TCP, UDP, SIP, RTP, RTCP, STUN, and TURN. These protocols facilitate the smooth
transmission of media streams, ensure security, and manage connectivity between participants. 
Determining how to choose and implement these protocols is the primary challenge you will address.
Alternatively, you have the option to design your own protocol.
Basic Part (85%)
In the basic part, you are required to implement a video meeting system based on Client-Server
(CS) framework. In this system, the server manages and records multiple conference rooms and
user operations, while users can act as clients to communicate with the server by creating,
joining, and exiting meetings.
In a detail, functions of server:
Manage and record meeting statuses (such as creating and terminating meetings) and track
client actions (such as joining and leaving).
Forward client data to facilitate communication among participants.
Functions of client (Clients are divided into creators and participants):
Creators: request to create and terminate meeting.
Participant: join and exit meetings.
All clients: communicate with the server.
In each meeting, all users can send video, audio, and text messages at the same time. The server
is responsible for handling the broadcast of this information and ensuring that each client can
correctly receive and display content from other users. The specific requirements are as follows:
Basic transmission function (25%)
Text transmission(such as chat messages) function (5%)
Each client can send the text messages to server.
The server forwards the text messages to all other participants in the meeting.
The client should display all text messages from senders.
Each message should include the sender's name and the time-stamp to help
participants quickly identify the source of the information.
Video transmission function (10%)
Each user can choose to turn their camera on or off. Once the camera is activated, the
client should send the video stream to the server.
The server forwards the video stream to all other participants in the meeting.
The client should display the screens of all users who have their cameras turned on and
can show real-time video from multiple users using a split-screen or similar methods.
Audio transmission function (10%)
Each user can choose to turn their microphone on or off. Once the microphone is
activated, the client should send the audio stream to the server.
The server must receive and mix the audio streams from multiple users, distributing the
combined audio stream to all participants.
The client should play audio from other users and be capable of handling the play of
multiple audio streams simultaneously.
Note: Streaming data processing is a difficult aspect of the project. Grades will be assigned based on
performance, with smoother display and play resulting in higher scores during the presentation.
Meeting function(60%)
Single meeting mode (20%)
In this mode, two client will interact with a server: one client requests to create a meeting and
joins it, while the other client also joins the same meeting.
Create a Meeting (5 points): The client can send a request to the server to create a new
meeting. Once the meeting is successfully created, other users will be allowed to join.
Join a Meeting (5 points): The client can view a list of currently available meetings and
choose to join any of them. After joining, the client will participate in the meeting.
Exit the Meeting (5 points): The client can exit the current meeting at any time. Leaving the
meeting will not affect the ability of other client to continue participating.
Cancel the Meeting (5 points): The creator of the meeting can cancel it at any time. Once
the meeting is canceled, no new clients will be able to join, and those already in the meeting
will be removed. Additionally, the meeting will automatically end when all participants,
including the creator, have exited.
Complex Meeting Scenarios (40%)
1. Multiple participants participate in a meeting (20%). The meeting system must support
the simultaneous participation of multiple clients(at least 3 clients) to ensure smooth
communication through audio, video, and text. This extended version of the single meeting
mode emphasizes that each meeting must be capable of supporting multiple client
participants (tips: asynchronous io or multi-thread).
2. Multiple conferences in parallel (20%). The server should support multiple meetings
occurring at the same time. The founders of each meeting can be different, allowing various
users to create independent meetings. The specific requirements are as follows:
Independent Meeting Life Cycle (10%): The start and end of each meeting should be
independent of one another, ensuring that the status of one meeting does not affect
other meetings. All meetings should be able to proceed normally.
Content Isolation (10%): The content of each meeting should be completely isolated
from others; no meeting should receive audio or video data from other conferences.
The server must ensure that audio and video streams are transmitted exclusively
between users in the same meeting, thereby maintaining the privacy and independence
of each conference.
Bonus Part (20%)
In the bonus part, you are required to implement a video meeting system based on Peer-to-Peer
(P2P) framework. This system is similar to the Client-Server (CS) system, but in this case, the
server's role is limited to managing and recording meetings without forwarding data. The
specific requirements are as follows:
Two clients scenarios(10%): The client can request to create a meeting. In this meeting, two
clients communicate directly with each other.
Mode switch(10%): The server can determine the most suitable mode for different meetings
and switch accordingly between Client-Server (CS) and Peer-to-Peer (P2P) (For instance,
when two clients are in a meeting, it operates in P2P mode, and when three clients are in a
meeting, it switches to CS mode.).
Note: The bonus part is relatively loose, and you can do it yourself. But at the same time, how to show
that your data is not forwarded by server in P2P scenarios and whether the mode is switched in
different scenarios are also issues you need to consider.
Presentation (5%)
You will present your project in the lab class after December 20. Each group has a maximum of 
10 minutes to showcase their work. TAs may ask questions about your project during the
presentation, so a thorough understanding of your implemented functions is essential.
Provided Code
We have provided demo code for you to further understand the fucntions of server and client, as
well as the system structure (see Demo for Video Conference). It includes four files 
conf_client.py , conf_server.py , config.py , util.py . 
Note that this demo is just a reference. You don't need to follow it exactly and are encouraged
to implement a more efficient video conference service.
conf_client.py
There is a ConferenceClient class, with necessary fields to record client status or meeting
information. Following are some necessary function for client, each with description for its
functionality. All a client need to do are create connections, and do transmission (sending and
receiving).
In the start() method, we have provided a simple command line user interface to execute
certain function. But we won't mind that some of you can provide a better GUI for your clients.
conf_server.py
This is a simple demo for server with original implementation of asynchronized IO ( asyncio ).
There are two classes MainServer and ConferenceServer for possible multi-conference
implementation, where ConferenceServer handles clients within a single conference and 
MainConference manages multiple conference by handling multiple instances of 
ConferenceServer .
Note that any conference (with mode C-S or P2P) should be managed by server, while the
data transmission among clients depends on the mode of conference.
config.py
This file stores some necessary configuration of the conference service, including but not limited
to the service ports, server's IP address and other parameters to control the stream data and its
transmission.
util.py
This file includes some useful functions for data capture and image processing.

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