Addressing Smartphones Located Behind Firewalls
Name
Kristjan Reinloo
Abstract
In recent years, smartphones have become considerably popular. They are
inseparable companions for their owners while offering both entertainment and
assistance in daily routines.
Such popularity has different reasons - with the development of technologies
like touchscreens and microprocessors, smartphones are becoming more and more
powerful in terms of computational power. This sets preconditions for the
development of rather sophisticated software as well. Today it is already
possible to play 3D games or record high-definition videos with mobiles.
Moreover, smartphones and tablets are replacing laptops and desktops since they
offer almost the same functionality and user experience while fitting into
pockets and weighing only couple of hundred grams.
Most of the applications currently available for smartphones usually consume
different kind of resources from the Internet, thus acting as clients. But given
the fact that handheld devices have already roughly the same computational power
as low-end laptops and netbooks, it is possible to offer services from the
smartphones as well which could lead to new types of mobile applications and use
cases.
Unfortunately, it is not trivial to access smartphones or any other host from
the Internet due to widespread usage of some networking processes, for example,
network address translation (NAT). To overcome such difficulties problems, an
application suite is proposed in this thesis, which helps smartphones to become
accessible service provides not only within local network but also across the
Internet by mitigating some common addressing problems.
Proposed solution was implemented and tested in scenarios where the smartphone
whose services were accessed, was located behind a router which performed
network address translation. Even though the connection establishment was
successful, some limitations were identified, which included executing code with
root privileges in the smartphone, incremental NAT mapping by the routers and
relatively idle local network of both connecting peers.
As the current implementation is only an initial prototype, it is not yet mature
enough to be used in real applications. Nonetheless, given solution could be
improved in different ways, e.g. adding more NAT hole punching techniques which
have different prerequisites making it more stable in other network
environments. Also the functionality to discover the network and NAT properties
could be added.
Graduation Thesis language
English
Graduation Thesis type
Bachelor - Information Technology
Supervisor(s)
Satish Narayana Srirama
Defence year
2013