Network Research at CTI

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Network Research at CTI

• James Yu, Ph.D.
• Assistant Professor
• School of CTI
• jyu_at_cs.depaul.edu

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James Yu, Ph.D.

• Ph.D. in Computer Science from Purdue University,
  1985
• Distinguished Member of Technical Staff, Bell
  Labs, Lucent Technologies, 1985 2000
• Director of Network Technologies, ARBROS
  Communications, 2000 2001
• Assistant Professor, DePaul University, 2002 - now

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Research Interests

• Network Performance Evaluation
• Wireless Security
• VoIP Traffic Engineering
• Fault Tolerant Network Design
• Network education hands-on exercises for
  distance learning students

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Framework of Network Research
Problem Statement
Empirical Framework
Theoretical Model
References
Solutions to The problem
Revision
Data Analysis
Comparative Study
Conclusion
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Network the BIG Picture
PSTN
Network Services and Management
NNI
Switched Network
Internet
Access Network
Security Layer
Transport Network
ISP Network
UNI
carrier network
Security Layer
Security Layer
Data LAN
Voice Network
2G/3G Network
Data Center
Call Center
cellular network
converged enterprise network
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Project I Performance Analysis
Key measurement throughput (bps) and delay (ms
or ?s)
Ethernet Switch
IP Router
Linux Bridge/Router
Windows Bridge/Router
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One-way Delay (in ?s) on 100baseTX Link (Linux
Bridge vs. Linux Router)
Throughput (bps) on 100BaseTX Link (Linux Bridge
vs. Linux Router)
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Switch Performance Comparisonon Gigabit Ethernet
Question could you develop a problem statement
from this chart?
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Wireless Performance
Question why is TCP performance is only 50 of
the line rate for wireless communications?
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Project II Wireless Denial of Service (DoS)
Research
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TCP performance under DoS
Stop
Start
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Project III VoIP Research
PSTN Switch
PSTN Switch
SoftSwitch
SoftSwitch
Carrier VoIP Network
Trunk MG
Trunk MG
Call Manager (SIP Proxy)
Q.931
Access MG
Call Manager (Enterprise)
MG Media Gateway
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VoIP Traffic Engineering

• Design the network with sufficient capacity to
  meet the traffic demand with satisfactory
  performance
• Requirement assurance of Voice Quality.
• If call quality cannot be assured, reject the
  call request.
• Demand (A) - Traffic Intensity
• number of calls duration of average calls
• Erlang
• Resources (N) Network bandwidth (bps) and
  capacity (pps)
• Grade of Service (GoS) blocking probability

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Research Areas of VoIP

• IP Multimedia Subsystem (IMS)
• How is a VoIP call from one service provider to
  another service provider today?
• VoIP Security
• Voice Quality
• Quality of Service (QoS) over internet and
  intranet
• Supplemental and Intelligent Network (IN)
  services
• API and VoXML

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Project IV Fault Tolerant Network
RSL
Dual Homing
VRRP
RSTP (802.1w)
ISP-01
ISP-02

• Network Design Goal
• No single point of failure
• Failover time ltlt 1 sec

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Project V Remote Lab Access
Linux Gateway
Public Internet
Private Networking Labs
Windows Terminal Server
Devices w/ Console interface
Devices w/ IP interface
Telecom Terminal Server
Console interface
Problem Statement supporting distance learning
students to perform hands-on network exercises
from any place with 247 access to the network lab
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Conclusions

• Evolution of the telecom networks and network
  technologies
• Convergence of PSTN and Internet
• Growing demand for wireless networks (bandwidth
  utilization, more bandwidth, new applications,
  etc.)
• Increasing threat and concerns of network
  security
• Higher requirements for network reliability and
  service availability
• New generation of devices and services
• Needs more research work