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Tietoverkkolaboratorio
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IMELIO - Internet MEchanisms for quaLity and InterOperability
Journal papers
Raimo Kantola, Jose Costa Requena, Nicklas Beijar: Interoperable routing
for IN and IP Telephony, Computer Networks, 2001
This paper discusses the problem of interoperability of IP Telephony and
Switched Circuit Networks in the area of routing information. We describe
and analyze a solution for directory-based routing. We will present an
architecture based on a distributed database on the switched circuit network
and the IP network. The aim of the solution is to provide efficient service
management, close to optimal routing for all calls including calls to 800-
and cellular numbers and personal number portability between both network
technologies. The solution is based on similar but differing in detail
approaches for each network. In the IP network we use the Telephony Routing
over IP (TRIP) protocol developed by IETF. Additionally, the described
architecture is open for inclusion of the ENUM protocol that is under development.
For the circuit switched network, we suggest a new protocol called Circuit
Telephony Routing Information Protocol (CTRIP). The protocol provides a
distributed method for synchronizing routing information between databases.
Furthermore, we propose numbering gateways for transferring number information
between the two network types. We utilize the Server Cache Synchronization
Protocol (SCSP) as the common element for data synchronization and replication
among distributed entities. We also discuss briefly the design of a test
implementation of the proposed infrastructure functions and protocols under
development in our Laboratory. In conclusion, we propose to design a common
interoperable routing information infrastructure for the emerging hybrid
SCN/IP Telephony network.
Keywords: Voice over IP; number portability; directory; data
replication; data synchronization; protocol; routing; SCSP; TRIP; CTRIP;
ENUM
Conference papers
Zhansong Ma, Peng Zhang, Raimo Kantola: Influence of Link State Updating
on the Performance and Cost of QoS Routing in an Intranet. 2001 IEEE Workshop
on High Performance Switching and Routing (HPSR 2001), Dallas, Texas USA,
May 29-31, 2001
In recent years, QoS routing has been regarded as an essential enhancing
mechanism for providing differentiated QoS in the IP networks. QoS routing
needs link state updating (LSU) algorithms for acquiring accurate link
state information (e.g., available link bandwidth) to compute routes. However,
an unsuitable link state updating also brings excess computation and communication
cost so that seriously degrades the performance of QoS routing. In this
paper, we present four link state update algorithms for QoS routing in
an Intranet, i.e., period based (PB), threshold based (TB), equal class
based (ECB), and unequal class based (UCB) updating. By doing extensive
simulations, we investigate and compare their impact on the performance
and cost of on-demand QoS routing in an intranet. Our simulation results
prove that QoS routing can achieve both high performance and low cost under
the careful selection of LSU algorithms and their parameters.
Keywords: QoS routing, link state updating algorithms, performance
and cost
Peng Zhang, Zhansong Ma, Raimo Kantola: Designing A New Routing Simulator
for DiffServ MPLS Networks. 2001 International Symposium on Performance
Evaluation of Computer and Telecommunication Systems (SPECTS 2001), July
15-19, Orlando, Florida USA
In this paper, we present the design and implementation of a new routing
simulator called Extended QoS_based Routing Simulator (EQRS). EQRS is a
discrete-event simulator developed for studying constraint based routing
in the Internet. It is an upgraded version of QRS – QoS_based Routing Simulator
[1]. Our objective in this version is to provide new capabilities that
enable simulating DiffServ MPLS networks. EQRS allows users to configure
parameters of DiffServ MPLS networks, where the dynamics of constraint
based routing algorithms as well as traffic engineering mechanisms can
be investigated. Particularly, with the help of EQRS, we investigate the
performance and cost of QoS routing under a QoS routing algorithm and a
specific link state update (LSU) algorithm. The simulation results prove
that: 1) QoS routing acheives better network performance under careful
configuration; 2) the simulator is suitable for modeling, designing and
evaluating DiffServ MPLS networks.
Keywords: Differentiated Services (DiffServ), Multi Protocol
Label Switching (MPLS), Constraint Based Routing, Quality of Service, Link
State Update (LSU)
Mika Ilvesmäki, Sampo Kaikkonen: The length of measurement period
to determine the application profile for traffic classification in the
Internet, 2001 International Conference on Communications (ICC 2001), Helsinki.
We discuss the aspect of measurement period length in the detection of
dynamic application profiles in the future Internet solutions requiring
automatic network based traffic differentiation. We base the analysis on
a measurement-based method to form dynamic application profiles and observe
the effect of the measurement period to the quantity and quality on the
dynamic application profile. We see that the detected traffic profiles
are of reasonable size and contain relevant applications. The results indicate
that the measurement period has to be several hours in length and that
the measurement process should be ongoing to ensure valid and stabilized
application set.
Keywords: Traffic classification, traffic measurements, traffic
characterization
Thesis
Zhansong Ma: Performance/Cost Analysis of QoS Routing in the Intranet,
Espoo 2000.
QoS routing has been regarded as an important part in the evolution of
QoS-based service offerings in the Internet. It computes paths that are
subject to QoS requirements and can improve the utilization of network
resources. Besides benefits, QoS routing also results in cost. The main
cost of QoS routing includes path computation cost, link state update
cost and storage cost. Before deploying QoS routing into the Internet,
the performance/cost ratio of QoS routing still needs careful study. This
thesis aims to investigate this problem through simulation study. This
thesis begins with an overview of QoS in the Internet, in which some QoS
related components, e.g., Integrated Services with Resource Reservation
Protocol, Differentiated Services, MultiProtocol Label Switching and QoS
routing, etc., are introduced. Then, the problem of QoS routing in the
Internet is investigated. Also, some issues on implementing QoS routing
in the Internet are presented and discussed. In order to study the performance/cost
ratio of QoS routing, we designed and implemented a QoS routing simulator.
Particularly, two routing algorithms and four link state update algorithms
were implemented. With the help of the simulator, we analyzed the factors
that affect the performance/cost ratio of QoS routing. As results, we found
that the cost of QoS routing is very sensitive to network size, that the
cost can be significantly reduced by the use of suitable link state update
algorithms, that frequent requests cause high cost, that traffic pattern
is another factor that affects QoS routing cost. Some results presented
in this thesis can be used for guiding the deployment of QoS routing in
IP networks.
Keywords: Quality of Service, IntServ, RSVP, DiffServ, MPLS,
QoS routing
Julio Ramirez Yebenes: Scalability Analysis of the Server Cache Synchronization
Protocol, Espoo 2001.
Keywords: SCSP, Threads, Transpapency, Portability, Scalability,
Performance.
Juan Ventura Agustina: Impact of GPRS on Existing GSM Services, Espoo 2001.
Keywords: GPRS, GSM, channel allocation, GoS, handover performance,
network planning.
Full papers are either in PostScript or
PDF format.
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