Transcript Final Presentation

Development Of A
BingBee Phone
Network
Author: Taurai Saurombe
Supervisors: Prof Peter Wentworth & Dr Slay
Introduction
• Welcome
• In this presentation I am going to tell you
about the BingBee Phone Network Project, it’s
main components and how the network has
been constructed
Objectives
• This project is aligned with the BingBee
project whose aim is to raise literacy through
edutainment
• The aim of this project is to create a fully
functional VoIP system which is going to be
used for edutainment purposes, specifically
targeting young children in the Pre School age
group.
Proposed Single Site Network
Layout
Methodology
• The VoIP network developed is running using
Asterisk as a server and traditional IP handsets as
clients instead of cell phones which are the
current trend in phone edutainment at the
moment.
• Asterisk is an open source PBX system which
offers the flexibility customisable functionality
and features.
• The features that this VoIP network is providing
where added to Asterisk through development of
the Asterisk Dialplan.
Methodology
We used handsets instead of cell
phones because of the relative
low cost, better physical security
and durability of the handsets
and also, the improvement in the
handset technology and features
that are appearing these days as
shown below
Iwatsu Electric
Nortel
Currently being
used
Siemens
Methodology
• Another reason for
using these phones is
that the speakerphone
capability of these
phones is also
particularly useful in
our case because it lets
groups of children listen
at the same time to the
same phone.
Currently being
used
About The System
• The system was developed to offer the following
functions.
 Plain telephone calls between handsets
 Provide functionality for book readouts with the ability to
navigate between different pages
 Offer some arithmetic games which will be played in
response to an Interactive Voice Response Menu from the
system.
 Offer a verbal counting activity to teach numbers to the
young children in both Xhosa and English
The Book Readout Functionality
• The Book Readout function is so far the main
functionality that this system provides
• To make this function as dynamic as possible,
additional effort was made to develop the
ordinarily static Asterisk Dialplan to cater for
additional content that will be made in the future
• Ordinarily the static Dialplan requires that each
page in each book be added to the Dialplan
manually for it to be available on the system
The Book Readout Functionality
• But now we've managed to use wildcard
matching and tests for files which allows us to
be able to dynamically add new books by
simply dropping their audio tracks into a folder
numbered with the extension that will
designate the book
• This means that the drop-in feature makes it
possible in future for the teachers or other
content providers to build a content collection
without needing intervention from the
programmer
The Book Readout Functionality
• Additional books can now be added to the
system and be automatically available
immediately to the users without
reconfiguring the Dialplan as would
ordinarily be necessary
• This functionality can be used for more
than just books, we are now able to have
audio tracks that teach counting or any
sing-along songs, e.g. to teach the
alphabet Or we can add audio tracks that
tell stories
Problems Encountered
• One of the problems encountered was the
unreliability of phone calls between handsets
which was caused by the port ranging nature of
RTP streams between the phone handsets and the
interaction between the Operating system firewall
and the RTP media streams
• RTP uses a dynamic port range of 16384-32767
which makes it particularly difficult to configure a
firewall to let the packets pass through
• In this closed network the server firewall is
temporarily switched off.
Problems Encountered
• Another problem I encountered was the
difficulty I had in sourcing Xhosa readers
to translate some of the material we had
in English into Xhosa
Method of Approach
• The Extreme Programming methodology was being followed
in the implementation of this project so for each function that
we added to the system user stories were first developed for
each function
User Story 1 . Users can dial another phone in a
different place by the Speed Dial facility using a single or
double digit number and then pressing “Speed” to dial any
of the numbers in the phone address book.
User Story 2 . Users can clearly hear each other over
the phones( satisfactory voice quality and clarity) {this user
story is however not an issue since the LAN network we are dealing
with at the moment provides high bandwidth so the lower quality
codecs are unnecessary}
Method of Approach
• User Story 3 . Users can dial a number on
the front of a book, and the phone will play
back the book to the user page by page
(system is capable of navigation between the
pages if so desired)
• User Story 4 Users dial an extension. After
that every time the user presses a key the
phone will tell the user which number they
have dialled in either English, Xhosa, or both
the languages depending on which extension
or Speed Dial the user pressed
Method of Approach
• User Story 5 . Users can dial a pre
assigned number or Speed Dial for
either a Division, Multiplication,
Addition or Subtraction calculation.
Phone will prompt the user for the
two numbers to calculate, separated
by pressing the asterisk “*” key. User
will then be told the answer to the
mathematical problem by the phone
EndNotes
• It was our original intention to
deploy at Raglan Road, but instead
we’re deploying here in the building
as a test site, and then later move on
to offsite deployment, with a central
server housed here.
Conclusion
• There is a lot of work being done on
increasing the amount of services that can
be offered on a phone.
• This project is a step towards the goal of
providing edutainment services over phones
and with the improvement of VoIP handsets
we should see more complicated services
being offered over handsets.
Conclusion
• Essentially this project is a proof of concept
that an edutainment service over IP Phones
is possible to supply now in South Africa and
that IP Phone handsets can be used for this
purpose and from the services that we have
been able to develop on this project, I am
confident that other uses for this kind of
system can be found for this kind of system,
e.g. auto menus for take-away restaurants
Conclusion
• One area that can be investigated for
possible future work would be to see
whether we can deliver higher-quality
audio through the system via different
codecs. This needs capability both on the
Phone and the Server side.
• Also delivering this service to multiple
locations spread across the country can
be investigated further and although NAT
issues will have to be dealt with and
possibly switch from the SIP protocol we
are currently using to IAX2 which is
designed to be more NAT friendly
Questions?