SATNAC 2007 Conference Papers
Network Engineering
Title: Evaluation
of Multiple Interface Functionality and Flow Mobility
Authors:
Gareth Abrey (University of Cape Town),
Neco Ventura (University of Cape Town)
Abstract:
The Internet and mobile communications are converging towards a single,
globally connected network. The latest mobile devices are increasingly
equipped with multiple access technologies. These interfaces will prove
most useful if used in collaboration. The functionality possible with
multiple interfaces is evaluated on a test-bed in this paper to
determine the success of a typical multiple interface scheme. Our
results show that there are distinct advantages in using
multiple
interfaces for data flows, however some scenarios illustrate potential
performance problems under certain conditions.
Title: Mapping
the African Internet
Authors:
John Gilmore (University of
Stellenbosch),
Anthony Krzesinski (University of Stellenbosch)
Abstract:
This paper describes the methods used to generate a router level map of
the African Internet. The traceroute utility was used to collect router
level information on the Internet. We developed software to automate
the sending of traceroute probes to selected IP addresses, to store the
information produced by the traceroute data and to transform the data
into adjacency matrices. The adjacency matrices, together with
geographical data concerning the location of the routers, were used to
draw a map showing the Internet topology.
Title: A
Distributed Scheme for Robust On-Line Network Engineering
Authors:
Johannes Goebel (University of Hamburg,
Germany),
Anthony Krzesinski (University of Stellenbosch), Dieter Stapelberg
(University of Stellenbosch)
Abstract:
This paper presents a model of an on-line network bandwidth management
scheme: at random time instants bandwidth prices are computed and are
used to adjust the bandwidths of the network paths in response to the
traffic conditions. The distinguishing features of the scheme are that
it works without centralised control and thus scales to large networks,
and that rather than using traffic engineering to move network flows to
where the network bandwidth is located, network engineering is used to
move bandwidth to where the flows are located. Simulation results show
that the reallocation scheme provides prompt and robust bandwidth
provisioning.
Title: Investigation
into Performance Metrics for Connection Admission Control
in an MPLS Simulated Network
Authors:
Prathaban Moodley (University of the
Witwatersrand),
Hu Hanrahan (University of the Witwatersrand)
Abstract:
The future multiservice communication network will be packet based.
Existing circuit switched telco networks have been designed on traffic
engineering principles, ensuring guaranteed QoS for all classes of
traffic within the network. Existing traffic models for circuit
switched networks do not apply to a packetised network. Many packet
based technologies do not address QoS. The traffic engineering feature
of MPLS provides the best QoS function for packetised IP networks today
(apart from legacy ATM). A Connection Admission Control function is
required to ensure guaranteed services for class based or path based
traffic over a packetised network. This paper addresses the question of
whether information gathered from the network could be useful in
informing the Connection Admission Control function. The network is
represented by the NS-2 network simulator. Performance metrics
(latency, jitter, and packet loss) are recorded during various
simulated network conditions. These simulated network conditions
include:- step load, dynamic load, busy hour and disaster events.
Traffic classes include common telco traffic:- web, ftp, voice and
video traffic. Performance metrics provide insight into the state of
the network and is useful for informing the design and operation of the
Connection Admission Control function.
Title: An
Optimal Pricing Model for Wireless Community Mesh Networks
Authors:
Hai Ling Zhu (University of Johannesburg),
Wimpie Clarke (University of Johannesburg), Andre Nel (University of
Johannesburg), Marco dos Santos (University of Johannesburg)
Abstract:
The development of wireless LAN technologies offers a novel platform
for internet service resale via wireless community mesh networks that
provide high network coverage and lower infrastructure cost. In a
wireless community mesh network, access point functions as both the
Internet service provider and Internet access provider to the mesh
network neighbors (end-users) since the upstream Internet service
providers of the access point is not able to monitor and bill for the
resold traffic within the community mesh network. In this Internet
service resale business, the access provider sets their pricing policy
as an Internet reseller to maximize its revenue, while the end-users
who are price sensitive, respond to this pricing policy by controlling
their Internet usage. Using a queuing theory model, we propose an
optimal pricing model to achieve revenue maximization for a mesh
network access provider. The user’s sensitivity to the price
is
modeled in order to discover the optimal price. The effects of the
price on the traffic load and the maximum number of users at the access
point are explored since price is viewed as an additional strategy to
encourage a better usage of the limited bandwidth resource. Monte Carlo
simulation results are presented to verify the analytically optimal
price based on the proposed pricing model.