MCS: Archiving System Mechanism

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					                                                          (IJCSIS) International Journal of Computer Science and Information Security,
                                                          Vol. 10, No. 4, April 2012

                                       MCS: Archiving System Mechanism
    P   Husein A. Hiyasat, 1Hazem Nagawi, 1Ababneh Jafar, 1Adeeb Al-Saaidah, 1Abd-Jaber Hussein, 1, 2Mahmoud Baklizi
        P                  P   P                  P   P         P   P                                               P   P

                        1:Department of Computer Sciences, The World Islamic Sciences and Education
                                    (W.I.S.E.) University, Amman, 11947, P.O. Box 1101
                                    2: National Advanced IPv6 Center of Excellence , Universiti Sains Malaysia
                                                    Penang, Malaysia
         1:{husein.hiyasat, hazem.nagawi, jafar.ababneh,, hussein.abdeljaber, mbaklizi }

Abstract— Nowadays, the Video conferencing systems are                       multimedia PC can probably become an MCS client.
widely used in many areas. The multimedia conference system                  Majority of the multimedia conferencing systems try to
(MCS) is one of the Video conferencing systems which                         supply real-time connections as well as receive and transmit
increasingly gaining acceptance because of its unique features.              capabilities [7]. MCS is the only desktop video conferencing
However, the MCS is lacking of the archiving system which
used to store the session data for later retrieve. This paper
                                                                             system that uses the RSW control criteria. RSW control
proposed to add archiving server to the MCS, in order to store               protocol is used to develop MCS and make enhance its
the session data. The proposed archiving system store four                   efficiency [8][9]. MCS clients do not record the sessions
types of media data, which they are video, audio, files, and                 after or during the session lifetime. Usually the participants
chat. The four types of media data stored in the archiving                   of video conference hope to store the session and replay in
server through FTP session between the archiving server and                  later time. Therefore, this paper proposes a mechanism to
the client.                                                                  store the video conference session in a way that facilitates
                                                                             restoring the whole session for future replay.
Keywords- Multimedia Conferencing System (MCS), RSW                                        II.     RSW CONTROL PROTOCOL
Control Protocol, Archiving server.
                                                                             The Real time Switching (RSW) control protocol was
                                                                             designed and developed by the network research group in
                      I.           INTRODUCTION                              School of Computer Sciences, University Science Malaysia
                                                                             (USM) in 1993.
Videoconferencing becomes more and more popular in                           The idea of how a real conference conducted a round table
personal communications, education , business and                            meeting is implemented in the RSW. The RSW control
government activities, The idea of video conferencing                        protocol was designed for two reasons: (i) Avoiding
appeared in 1920s [1]. CSCW (Computer-Support                                confusion when everybody speaks at the same time. (ii)
Cooperative Work) was adopted by Greif and Cash-man in                       Reducing the network traffic during the conference
1984, according to Greif, computer-support cooperative                       [10][11].Moreover, RSW achieves more improvement in
work relates to how groups can collaborate in using                          VoIP in reducing the packet delay to reduce the network
computer technology [2]. Videoconference is a group                          traffic, when a comparison between RSW and SIP(Session
consisted of two or more people conversation, which                          Initiation Protocol) was made in [12] that used for creating,
operates real-time multimedia communication technology to                    modifying, and terminating sessions with one or more
enable participants at different geographical locations to see,              participants, we found RSW performs slightly better than
hear and send files to each other and make groups                            SIP protocol in fixed packet delay as shown in Fig 1.
communication more effective at their work. Many of
organizations have meeting spaces [3, 4, 5, and 6]. Each
organization focuses on a different research model for
classroom use.

Nowadays, Multimedia Conferencing System or popularly
known as MCS Desktop Conferencing System has become
extremely popular in real time meetings and conferences. It
is a video conferencing system that can seamlessly integrate
into the current network architecture of an organization. It
was designed to fit into any existing LAN and WAN
environment and MCS. It is also software based and uses
non-proprietary hardware. This means your existing                                      Figure 1. Packet Delay - SIP versus RSW [12].

                                                                                                          ISSN 1947-5500
                                                    (IJCSIS) International Journal of Computer Science and Information Security,
                                                    Vol. 10, No. 4, April 2012

RSW control criteria depend on six different options for            sending and capturing audio and video streaming, chatting
ordering and controlling a multimedia conferencing system.          and files transferring. The Archiving server that allows
                                                                    interweaving between the MCS can be architected in a two
- Equal Privileges: all conference sites have an equal              ways; inside the MCS environment, or outside the MCS
opportunity of becoming active sites. The user that gets            environment.
active site status is also given main site status and the
privilege of choosing the next active site.                          Interweaving between MCS and Archiving Server require
- First come first serve: the RSW will assign active site           the existence the following entities:
status to the sites in the order the request comes in.
- First come first serve, with time-out: this option is             - MCS Server entity: The MCS server is an entity that
similar to option 2, but each site is only allowed a certain        controls the functions of a conference. It provides users with
maximum time limit.
                                                                    a platform     to    register/login    for    participating in
- Organizer Main site: the RSW gives the privileges of              conferences. It also provides coordinates multicast address
choosing the active site to the site that organizes the
                                                                    assignments. In addition, it provides damage control when
conference.                                                         links break or when entities “crash”. Finally, during
- Restricted Active sites: the organizing (chairman) site           multiple conferences it establishes inter-server links.
will act as an access appeaser for the sites allowed to
participate in the conference.
- Restricted active sites, upgradeable observer sites: This          -MCS Client: MCS client is an endpoint user in the
option is similar to option 5, except that the ability of           session, which has multiple ways to communicate with
changing observer site to active site in real time.                 other MCS clients. That captures and sends video and audio
                                                                    streams and controls file migrations and chatting.
Any combination of these options can be used to control a
conference as long as no contradictions arise. Moreover, a          -Archiving Server: is a storage server stores all the session
conference is made up of a conference chairman, which is            actions such as sending and capturing audio and video
the organizer of the conference, participants and observers         streaming, chatting and files transferring, In order to be
[10].                                                               retrieved and replayed later on. The MCS side Starts and
                                                                    terminates MCS signaling in the MCS network.
                 III.   ARCHIVING SYSTEM
                                                                        The address of Archiving Server must be known for the
                                                                    MCS side. The MCS client can appoint the archiving server.
Archiving system is coming from the importance of the               Fig 2 shows the internetworking configuration of the
indexing files and information data to be useful information        system.
and easy to coordinate and manage. A digital classroom and
Acrobat Connect are good examples for Archiving systems.
A digital classroom is a classroom meeting space that has
capability to archive multimedia information and classroom
activity in order to review at a later time [13]. Acrobat
Connect was designed to provide real time meeting space. It
is provide audio, video, chat and whiteboard functions. Also
Acrobat Connect it has capability archive meeting and
access through web URL [14].


Based on RSW control protocol, we propose an archiving                Figure 2. Configuration of Interweaving between RSW and Archiving
system that can handles all client actions in the MCS such                                            Server.
as audio, video, chat, and exchanged files. The proposed
archiving system can operate with any MCS client.                   B. Archiving System Module

A. Interweaving between RSW and Archiving Server                    There are two types of registration that will occur before
                                                                    any conferences are ventured in MCS. Each MCS server
Interweaving between RSW and Archiving Server is based              should register it-self to other MCS servers. The second
on MCS. The goal of interweaving between RSW and                    type of registration is the process by which an MCS client
Archiving Server is to store all the session actions such as        login to MCS server, and informs the server of its IP

                                                                                                  ISSN 1947-5500
                                                           (IJCSIS) International Journal of Computer Science and Information Security,
                                                           Vol. 10, No. 4, April 2012

address. Also Archiving Server, which is considered part of
MCS system, its IP address should be published to the MCS
clients. Depending on RSW Control Criteria, MCS server
will respond with either a formal approval or a reject
message. The Archiving Server start storing session after the
MCS client creates a session. Therefore, Media processing
within the Archiving Server will be simple; since we will
use file transfer protocol (FTP) in Archiving Server
networks for storing media. Interweaving between MCS and
Archiving Server involve two types of Endpoints: MCS
clients and Archiving Server.

C. Analysis of Archiving System Components

     Archiving Server module, which is considered as a part
of the system, will be analyzed. Fig 3 shows use case
diagram for Archiving Server. Archiving Server should be
registered to MCS clients when the session created. The
Archiving Server contains the module for storing media.

                                                                               Figure 4. MCS to Archiving Server session storing mechanism

                                                                         When the client of MCS invited to a conference, he will
                                                                         send two messages, the first one is JOIN message to join to
                                                                         the conference session and the second one is REQ-ACTIVE
                                                                         message to ask MCS server for activation. The MCS server
                                                                         sends message that indicates the user if he is allowed to join
                                                                         the conference and he gets all information needed. After the
             Figure 3. Archiving Server Use Case Diagram
                                                                         client becomes active he has the ability and privilege to send
                                                                         session media such as audio, video, chat and files. When
                                                                         streaming audio and video (Using RTP) sent from the client
D. Archiving Data Mechanism
                                                                         to other parties the archive server which has special shared
                                                                         folder and a static IP will receive the buffered data as a file
When establishing a call connection between MCS Clients                  named with the session name concatenated with the
and Archiving Server, we need to know the local and                      username and timestamp(date and time).
remote media transport addresses at which the Archiving
Server can receive the media session packets [15]. Fig 4
                                                                          Storing data will be done using CFile Class (which is
shows the archiving session storing mechanism.
                                                                         developed by Microsoft) by capturing a copy of the data of
                                                                         the buffers that existing on each client and before the header
Before starting the session the client of MCS sends a login              section is added to it. This copy of the buffered data is
requests to the server (C_USER_LOGIN). When the client                   retrieved from buffers and saved into files on the archive
receives the reply (S_USER_LOGIN) from the MCS server,                   server under a Microsoft Operating System using FTP
if the login is authorized, then the client can ask the MCS              protocol if and only if the same data of the buffer is
server whether if he is allowed to create a conference or not.           successfully sent through RTP protocol and before the
The MCS server sends a message back to the client in reply               buffer destruction, if sending data through RTP failed then
of conference creation request. It tells the user if he is               show the error message and release the packet from the
allowed to create the Conference or not, if it is allowed, it            buffer. As shown in Fig 5 Notice that RTP does not send
sends all the information about the conference needed.                   and/or receive files but Packets. For file exchanging, a copy

                                                                                                      ISSN 1947-5500
                                                        (IJCSIS) International Journal of Computer Science and Information Security,
                                                        Vol. 10, No. 4, April 2012

                                             Figure 5. The architecture of storing   session
of the exchanged file will be sent to the shared folder. For
chatting a pre-saved file already exists, on each device                [1]    E. M. Schooler, “Conferencing and collaborative computing,”
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