4. IP Telephony
IP telephony is a technology in which IP
networks are being used as the medium
to transmit voice traffic.
Voice over IP (VoIP)
Describes an IP telephony deployment where the IP network used
as the medium to transmit voice traffic is a managed IP network.
Voice on the Net (VON)
Describes an IP telephony deployment where the IP network used
as the medium to transmit voice traffic is the Internet.
5. Working of VoIP Phone
VoIP Phone
Requires broadband internet access and regular house
phones which plug into an analog telephone adapter (ATA).
Working of VoIP
works by the two-way transmission of voice over a
packet-switched IP network
Equipments
VoIP phone
call server
gateway.
6. Protocols in IP Telephony
Signaling protocols
perform session management and are responsible for
Locating a user
Session establishment
Session setup negotiation
Modifying a session
Tearing down a session
9. Vulnerabilities
Confidentiality
Refers to the protection of data from being read by
an unauthorized user.
Integrity
Includes the unauthorized modification or deletion of
voice/data content.
Availability
Storage and transportation facilities for an information
system are accessible to authorized users
10. Confidentiality
Data Link Layer
Address Resolution Protocol
Network Layer
Address Spoofing
Identifying IP Address of the Phone
Transport Layer
Real Time Protocol
Application Layer
MAC Address Spoofing
12. Availability
Bandwidth consumption
Comprise of flooding the network
with a specific type of traffic.
Resource Starvation attacks
Flood a device (opposed to links
in a bandwidth consumption attack).
Routing Attacks
Involve manipulating routing information or protocols
in order to intercept / interrupt legitimate traffic.
Programming Flaws
Unintended bugs in software that can be exploited by
other user in order to gain access to a system .
13. VoIP Security Tools
VoIP systems become more prevalent and risk grows,
network engineers need to make sure the proper
precautions are taken to prevent security breaches.
Some testing tools
SiVuS
c07-sip
14. SiVuS
First publicly available vulnerability scanner for VoIP networks.
SIP Message generator
Used to test issues or generate demonstration attacks
SIP component discovery
Useful for identifying targets for analysis.
SIP vulnerability scanner
Used to verify the robustness and security of SIP phones,
proxy servers and registrar servers .
15. Strengths
Windows-based GUI design
Reports are generated in an easy
to read html page
Checks both the robustness and the
presence of security features
16. Weaknesses
Lack of information
SIP device failed to locate the Asterisk server
Issues arose on required SiVuS to be restarted.
authentication were found to report inaccurate
results.
Running the test cases repeatedly fails to find
a target on the first attempt
17. Conclusion
None of the security tools evaluated were significantly
effective for mitigating security risks in SIP-based
VoIP networks
Early stages of adoption, attacks have been either
largely unheard of or undetected
Particularly important to prevent DoS attacks
All tools today are still under heavy development and
will no doubt evolve as VoIP adoption increases
VoIP specific security tools should play an important
role in securing systems.
18. References
B. Charney, "VoIP threats 'must be dealt with now,'“
CNET News.com, 8 Feb. 2005;
J. E. Canavan, Fundamentals of Network Security,
Boston: Artech House, 2001
L.N.Vikram,Web Design And Multimedia Applications
4th Edition, Pearson Educations
Sikinder S.R.R.C, Voice On Internet Protocol A Basic
Approach, Charles House,2007
www.wikipedia.org.in
www.google.com
Digit magazine