Network Research at CDM James Yu, Ph.D. Associate Professor School of Computing jyu@cdm.depaul.edu 3/15/2016 CSC426 1 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/Associate Professor, DePaul University, 2002 - now 3/15/2016 CSC426 2 Research Interests Wireless Security VoIP Traffic Engineering Network Management Fault Tolerant Network Design Network education: hands-on exercises for distance learning students 3/15/2016 CSC426 3 Framework of Network Research (I) References Problem Statement Empirical Framework Theoretical Model Solutions to The problem Revision Data Analysis Comparative Study 3/15/2016 CSC426 Conclusion 4 Framework of Network Research (II) Problem Statement Empirical Framework Data Analysis Solutions to The problem Comparative Study Conclusion 3/15/2016 CSC426 Theoretical Model Data Analysis Your solution must be theoretical sound along with empirical support. 5 Problem Statement Is the problem significant and interesting? – References, References, References Can you describe the problem in one or two sentences? Can you describe the problems with numbers? Is the problem solvable? Is the problem already solved? Do not confuse the problem with the solution. 3/15/2016 CSC426 6 Measurement “When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be." [Lord Kelvin, PLA, vol. 1, "Electrical Units of Measurement", 1883-05-03] 3/15/2016 CSC426 7 Dependent Variable(s) vs. Independent Variables Y = F (X1, X2, X3, …..) 3/15/2016 CSC426 8 Review of Research Paper 1-2 page of each paper you read Problem Statement Results and Major Conclusions Research Methodology (empirical or theoretical) Comparison with other research work Your assessment Can you reproduce the research results? Can you improve the research results? 3/15/2016 CSC426 9 NETWORK RESEARCH PROJECTS 3/15/2016 CSC426 10 Network: the BIG Picture NNI PSTN ISP Network Access Network Security Layer Internet Network Services and Management Switched Network Transport Network UNI carrier network Security Layer Data LAN Voice Network Data Center Call Center Security Layer 2G/3G Network cellular network converged enterprise network 3/15/2016 CSC426 11 Project I: Performance Analysis Key measurement: throughput (bps) and delay (ms or s) Ethernet Switch IP Router Linux Bridge/Router Windows Bridge/Router 3/15/2016 CSC426 12 Switch Performance Comparison on Gigabit Ethernet 100.00% 90.00% 80.00% 70.00% 60.00% 100M 1000M 50.00% 40.00% 30.00% 20.00% 10.00% 0.00% Switch Linux Windows Question: could you develop a problem statement from this chart? 3/15/2016 CSC426 13 Wireless Performance 60 50 Line Speed 40 UDP TCP 30 Question: why is TCP performance is only 50% of the line rate for wireless communications? 20 10 0 802.11b 3/15/2016 802.11g CSC426 14 Project II: Wireless Denial of Service (DoS) Research 3/15/2016 CSC426 15 TCP performance under DoS Start 3/15/2016 Stop CSC426 16 Project III: VoIP Research SS7 SS7 PSTN Switch SoftSwitch SoftSwitch Carrier VoIP Network Trunk MG PSTN Switch IP (internal) Trunk MG Call Manager (SIP Proxy) Q.931 Access MG V IP (public) IP (private) Call Manager (Enterprise) MG: Media Gateway 3/15/2016 CSC426 17 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 3/15/2016 CSC426 18 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 3/15/2016 CSC426 19 Project IV: Fault Tolerant Network RSL RSTP (802.1w) VRRP Dual Homing ISP-01 ISP-02 Network Design Goal: 1. No single point of failure 2. Failover time << 1 sec 3/15/2016 CSC426 20 Project V: Remote Lab Access Linux Gateway Private Networking Labs Public Internet Windows Terminal Server Devices w/ Console interface Console interface Telecom Terminal Server Devices w/ IP interface Problem Statement: supporting distance learning students to perform hands-on network exercises from any place with 24×7 access to the network lab 3/15/2016 CSC426 21 Research on Networking Education Does the DL environment support the same learning goals effectively as the inclass students? – How do you define and measure the conformance to the learning goals and the effectiveness of the learning environment? Does multiple choice questions measure the learning as effective as other methods? 3/15/2016 CSC426 22 Project VI: Network Management CommandOriented Vendor specific VariableOriented SNMP/MIB CORBA Object-Oriented 04/27/09 DocumentOriented XML-Based TransactionOriented NETCONF 23 DePaul University NETCONF A new Protocol from IETF It is designed to address many current issues of network mangement. XML-based and Transaction-Based – The XML standard is well defined – The XML Schema allows flexible definition of the structured management information – download/upload of complete device configuration – human-readable – cost-effective to develop new applications and services Integration with security infrastructure Open issue – a lack of data models 04/27/09 24 DePaul University Research Deliverables No deliverables; no research Publications, Publications, Publications – Journal Papers – only if accepted – Conference Papers – Technical Reports (little weight) – Grant proposals – only if awarded – Whitepapers? (does not count) Tools, Demo, etc – good only if you have publications associated with them. 3/15/2016 CSC426 25 Technical Writings It is more important than your technical capabilities. Actually, it is a lot more important. Take a technical writing course if you have never taken one. use the DePaul Writing Labs William Strunk Jr. the Element of Style Yes, we are very picky (and extremely picky) 3/15/2016 CSC426 26 Recommendations There is no shortcut for research. Your approach may not work. Actually, it is not likely to work most of the time, but do not give up. You may find an elegant solution if you redefine the problem. Be flexible. If this is your 1st or 2nd year, you may try to reproduce with minor refinement of others research work. Be in a research team. If not, keep regular contact and discussion with other Ph.D. students. Build your community now (CSC426) It is easier to publish at SoCRS and you should do it. 3/15/2016 CSC426 27