Network Research at CTI James Yu, Ph.D. Assistant Professor School of CTI jyu@cs.depaul.edu 11/10/2018 DePaul University
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 11/10/2018 DePaul University
Research Interests Network Performance Evaluation Wireless Security VoIP Traffic Engineering Fault Tolerant Network Design Network education: hands-on exercises for distance learning students 11/10/2018 DePaul University
Framework of Network Research Problem Statement Empirical Framework Theoretical Model References Solutions to The problem Revision Data Analysis Comparative Study Conclusion 11/10/2018 DePaul University
Services and Management Network: the BIG Picture PSTN NNI Network Services and Management Internet Network Access Switched 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 11/10/2018 DePaul University
Project I: Performance Analysis Key measurement: throughput (bps) and delay (ms or s) Ethernet Switch IP Router Linux Bridge/Router Windows Bridge/Router 11/10/2018 DePaul University
Throughput (bps) on 100BaseTX Link (Linux Bridge vs. Linux Router) One-way Delay (in s) on 100baseTX Link (Linux Bridge vs. Linux Router) Throughput (bps) on 100BaseTX Link (Linux Bridge vs. Linux Router) 11/10/2018 DePaul University
Switch Performance Comparison on Gigabit Ethernet Question: could you develop a problem statement from this chart? 11/10/2018 DePaul University
Wireless Performance Question: why is TCP performance is only 50% of the line rate for wireless communications? 11/10/2018 DePaul University
Project II: Wireless Denial of Service (DoS) Research 11/10/2018 DePaul University
TCP performance under DoS Stop Start 11/10/2018 DePaul University
Project III: VoIP Research SS7 SS7 PSTN Switch PSTN Switch SoftSwitch SoftSwitch Carrier VoIP Network Trunk MG Trunk MG IP (internal) Call Manager (SIP Proxy) Q.931 Access MG IP (public) IP (private) Call Manager (Enterprise) MG: Media Gateway 11/10/2018 DePaul University
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 11/10/2018 DePaul University
Research Areas of VoIP IP Multimedia Subsystem (IMS) VoIP Security 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 11/10/2018 DePaul University
Project IV: Fault Tolerant Network RSL RSTP (802.1w) VRRP Dual Homing ISP-01 ISP-02 Network Design Goal: No single point of failure Failover time << 1 sec 11/10/2018 DePaul University
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 24×7 access to the network lab 11/10/2018 DePaul University
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 11/10/2018 DePaul University