VoIP

1
VoIP () SecurityCOMS 4995-03

• Henning Schulzrinne
• Dept. of Computer Science
• Columbia University
• Fall 2008

2
Overview

• Course outline
• Prerequisites
• Course mechanics
• Projects

3
Course outline topics

• History, background, motivation
• IETF and standardization
• Intro to SIP (Ott)
• RTP
• 3GPP
• Conferencing
• Events and Presence
• SIMPLE XMPP
• Rich presence, policies, XCAP
• MSRP
• NATs, STUN, TURN, ICE

• GEOPRIV, Emergency calling, location conveyance
• Call control (CPL, sip-cgi, servlets)
• Peering (SPEERMINT)
• Jingle
• Skype
• Security threats
• Spam email, SIP I-D, SPF
• Identity
• DDOS

4
Course components

• (Few) instructor lectures to start
• 2 presentations for each student
• 30 minutes questions
• 3-4 so invited talks
• lab sessions and reports
• programming project
• no exam

5
Lab sessions

• Team projects (2-3 members)
• Take place in IRT lab, CLIC or MRL
• 4 topics
• Set up PBX (proxy, phones)
• Asterisk, openSER, ...
• Media (conference) server, VoiceXML
• Performance test
• Buffer overflow and security tests
• Lab report for each (HOW-TO)

6
Programming project

• Implement (emerging) standard
• Team projects (2 per team)
• Detailed project plan by 9/20
• Must demonstrate interoperability where
  applicable
• Try to find niche compared to existing projects
• Different language, OS,
• Java or C/C
• Two presentations
• Mid-term presentation (10 min.)
• Final presentation (20 min)

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Project topics

• Audio AGC
• RTP library (Java)
• IM conferencing (chat room)
• SIP identity framework (crypto)
• SRTP (secure media delivery)
• MSRP (media streaming)
• XCAP (configuration)
• STUN (NAT traversal)
• TURN (NAT traversal)

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Course goals

• understand current technology systems,
  components, protocols
• critical evaluation why? how else? what can we
  learn from this?
• presentation skills part of your grade
• goal canonical presentation on topics
• expect to find your slides in lots of other slide
  decks
• interactive discussion questions in class, on
  mailing list

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Am I in the right room?

• This course does not address
• web services (SOAP) ? Web-enhanced Information
  Management class, 6998
• routing
• multicast, IPv6,
• You should know
• general networking (e.g., 4119 Tanenbaum,
  Kurose/Ross, Bertsekas/Gallagher, etc.)
• network security basics (symmetric keys, PKI,
  hash, )
• C/C, maybe Java
• on Windows and/or Linux

10
Course mechanics

• Web page Wiki
• http//www.cs.columbia.edu/hgs/teaching/voip-secu
  rity
• http//wiki.cs.columbia.edu8080/display/hgs/VoIP
  Security
• Please note academic honesty policy
  http//www.cs.columbia.edu/education/honesty
• Mailing list voipsec_at_cs.columbia.edu
• Office hours MW, 4-5 pm, 450F CSB or by
  appointment
• Grading semester-long project 40, labs 30,
  presentations 30

11
Readings and text book

• No text book required
• Will provide references to papers, RFCs, I-Ds and
  chapters

12
Reference books general networking

• James F. Kurose and Keith W. Ross, Computer
  Networking A Top-Down Approach Featuring the
  Internet, Addison-Wesley, 3rd edition, 2004.
• Bruce S. Davie, Larry L. Peterson, Computer
  Networks A Systems Approach, Morgan Kaufman,
  2003, 3rd edition.
• W. R. Stevens, TCP/IP Illustrated, vol. 1.
  Reading, Massachusetts Addison-Wesley, 1994.
• D. E. Comer, Internetworking with TCP/IP, vol. 1.
  Englewood Cliffs, New Jersey Prentice Hall, 4th
  ed., 2000.
• D. E. Comer and D. L. Stevens, Internetworking
  with TCP/IP Design, Implementation, and
  Internals, vol. 2. Englewood Cliffs, New Jersey
  Prentice, Hall, 3rd ed., 1998.

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Reference books - multimedia and Internet
telephony

• John F. Koegel Buford, Multimedia Systems,
  Addison Wesley, 1994.
• Borko Furht, Handbook of Multimedia Computing,
  CRC, 1999.
• Ralf Steinmetz and Klara Nahrstedt, Multimedia
  Computing, Communications and Applications, 1995.
• RTP
• Colin Perkins, RTP, 2003
• SIP and IMS
• Miika Poikselka, Georg Mayer, Hisham Khartabil,
  Aki Niemi The IMS, Wiley, 2004
• G. Camarillo, M. Garcia-Martin, The 3G IP
  Multimedia Subsystem (IMS) Merging the Internet
  and the Cellular Worlds, Wiley, 2004
• Gonzalo Camarillo, SIP Demystified, McGraw-Hill,
  2002.
• Alan B. Johnston, SIP Understanding the Session
  Initiation Protocol, Artech House, 2000.

14
Journals and magazines

• All in ACM or IEEE digital library
• Journals
• IEEE/ACM Transactions on Networking (TON)
• Computer Communications Review (CCR)
• ACM Transactions on Multimedia Computing,
  Communications, and Applications (TOMCCAP)
• Magazines
• IEEE Communications Magazine (more physical
  layer)
• IEEE Network Magazine
• IEEE Wireless Communications
• IEEE MultiMedia
• IEEE Pervasive Computing
• Commercial magazines
• Alcatel, Lucent,
• Internet Protocol Journal (http//www.cisco.com/ip
  j)
• Cisco Packet (http//www.cisco.com/packet)

15
Related Conferences

• General networking
• IEEE Infocom
• ACM Sigcomm
• IEEE ICC and Globecom (more VoIP)
• ICNP (Int. Conference on Network Protocols)
• Multimedia
• ACM Multimedia
• NOSSDAV (Network and Operating Support for
  Digital Audio and Video)
• Other
• IMC (Internet Measurement Conference)
• PerCom (Pervasive Computing)

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Equipment

• Need headset (headphone, microphone)
• Possibly USB camera (web cam) for video project
• e.g., Logitech
• check support for OS platform youll be using
• Get early and test compatibility!