11 TAC2000/2000.7

802.16 IP Telephony Lab

IP Telephony (Voice over IP)

Associate Professor Quincy Wusolomon@voip.edu.tw

Graduate Institute of Communication EngineeringNational Chi Nan University

33 TAC2000/2000.7

802.16 IP Telephony Lab

What Is the Next Step? What will happen after VoIP is free?What will happen after VoIP is free? What do we need after free VoIP services become popular?What do we need after free VoIP services become popular?

Better voice qualityBetter voice quality What metrics are important to voice services?What metrics are important to voice services? How does the customers make sure they get the service quality they pay for?How does the customers make sure they get the service quality they pay for?

More flexible servicesMore flexible services Call waiting, call transfer, call blast, …Call waiting, call transfer, call blast, … Voicemail, conferencing, …Voicemail, conferencing, … Instant message & presenceInstant message & presence

Is there an easy way to create new VoIP services?Is there an easy way to create new VoIP services?

Stronger security requirementStronger security requirement DoS attackDoS attack

It is easier to protect your servers. How do you protect your WiFi phone?It is easier to protect your servers. How do you protect your WiFi phone? SPIT - SPAM over IP TelephonySPIT - SPAM over IP Telephony

SPIM – SPAM over Instant Message SPIM – SPAM over Instant Message

44 TAC2000/2000.7

802.16 IP Telephony Lab

Research Topics Discussion is required for individual student

QualityQuality SIP MobilitySIP Mobility

NAT Traversal (UDP and TCP)NAT Traversal (UDP and TCP) TLS (Transport Layer Security, RFC 2246)TLS (Transport Layer Security, RFC 2246) SCTP (Stream Control Transmission Protocol, RFC 2960)SCTP (Stream Control Transmission Protocol, RFC 2960) DCCP (Datagram Congestion Control Protocol, RFC 4340)DCCP (Datagram Congestion Control Protocol, RFC 4340)

Performance MeasurementPerformance Measurement OWAMP (One-way ping, RFC 3763)OWAMP (One-way ping, RFC 3763) PESQ (Perceptual Evaluation of Speech Quality, ITU-T P.862)PESQ (Perceptual Evaluation of Speech Quality, ITU-T P.862)

SecuritySecurity Real-Time Wiretapping Tools for VoIPReal-Time Wiretapping Tools for VoIP Automatic Detection of VoIP DoS AttacksAutomatic Detection of VoIP DoS Attacks Steganography in Speex & iLBC codecSteganography in Speex & iLBC codec Performance Comparision with Secure RTPPerformance Comparision with Secure RTP Performance Study of VoIP over Fast IPSecPerformance Study of VoIP over Fast IPSec

55 TAC2000/2000.7

802.16 IP Telephony Lab

NCNU PBX

SIP Proxy Server

PSTN Gateway

SIP Phone0944002002

StationInterface

StationInterface

Phone31924

Phone31533

Phone31842

Phone31350

StationInterface

Real-Time RTP Auditing

SIP Phone0944002003

SIP Proxy Server

TANet

NCTU

NCNUEdge Router

Edge Router

NCTU PBX

Softphone

WiMAXBS

PSTN Gateway

Real-Time RTP Auditing

LibpcapLibpcap oRTP libraryoRTP library Windows Audio Windows Audio

I/OI/OSpy

Spy

66 TAC2000/2000.7

802.16 IP Telephony Lab

Real-Time Audio Encryption

Real-time encryption Real-time encryption algorithmsalgorithms

Analysis of various codecsAnalysis of various codecs Schemes for key exchangeSchemes for key exchange Secure RTP (RFC 3711)Secure RTP (RFC 3711) Comparison with IPSecComparison with IPSec

Encrypted RTP Media Stream

Auditing

???

77 TAC2000/2000.7

802.16 IP Telephony Lab

Training Focus Three skillsThree skills

Implementation (Linux/FreeBSD, C/C++ programming)Implementation (Linux/FreeBSD, C/C++ programming) Solving difficult problems (using available tools & creating new tools)Solving difficult problems (using available tools & creating new tools) Presentation (speaking, writing)Presentation (speaking, writing)

Five disciplinesFive disciplines Always acknowledge important messages.Always acknowledge important messages. Backup your files.Backup your files. Constant progress is required; write weekly reports.Constant progress is required; write weekly reports. Documentation is required as you will see we have lots of SOP (standard Documentation is required as you will see we have lots of SOP (standard

operating procedure); do not overload yourself with trivial jobs.operating procedure); do not overload yourself with trivial jobs. English is the working language.English is the working language.

88 TAC2000/2000.7

802.16 IP Telephony Lab

Graduation Requirements PrototypePrototype

Finish your implementation before the summer vacation in the 1st gradeFinish your implementation before the summer vacation in the 1st grade

PresentationPresentation Read an English technical article every weekRead an English technical article every week

PaperPaper Publish a (domestic/international) conference paper before the winter Publish a (domestic/international) conference paper before the winter

vacationvacation

Oral defense will be arranged in May or November.Oral defense will be arranged in May or November.