Esta charla es acerca de las lecciones aprendidas operando el servicio SIP2SIP.info, una oferta para cuentas SIP gratuitas creada en el año 2004 usando software y estándares abiertos, incluye: Direccionamiento y numeración, Proxy SIP frente a diseño B2B, Aplicaciones más allá de VoIP, NAT: mejores prácticas, Mejores prácticas anti-fraude, Datos y Almacenamiento de contraseñas. Conferencista: Adrian Georgescu

1. AG Projects
SIP Infrastructure Experts
SIP2SIP
SIP accounts for the Masses
By Adrian Georgescu
Elastix World 2013 Mexico City

2. AG Projects
SIP Infrastructure Experts
Adrian Georgescu
ag@ag-projects.com
@agprojects
Founder and CEO

3. AG Projects
SIP Infrastructure Experts
AG Projects
SIP Infrastructure Experts
Since 2002
We are a software vendor specialized in the development and
deployment of real-time communications client and server solutions.
AG Projects develops, maintains or contributes to thirty software
packages among which are OpenSIPS, MediaProxy, OpenXCAP,
CDRTool, MSRP Relay, Blink, SylkServer and stacks for real-time
protocols and data-exchange mechanisms like SIP, TLS, XCAP, MSRP,
RTP, TLS, JSON, PUB/SUB and P2P DHT.

4. AG Projects
SIP Infrastructure Experts
About AG Projects

5. AG Projects
SIP Infrastructure Experts
Main Portfolio
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OpenSIPS - SIP Server (contributor and management)
OpenXCAP – Presence Policy Server
MediaProxy – Audio/video media relay
MSRP Relay – Chat /File Transfer media relay
CDRTool – Mediation and Accounting
SylkServer – Real-time Application Server

6. AG Projects
SIP Infrastructure Experts
Commercial Products
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MSP and SIP Thor - Turnkey SIP platforms
Blink - SIP Client for OSX, Linux and Windows

7. AG Projects
SIP Infrastructure Experts
Elastix World 2013
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Adrian Georgescu & Saúl Ibarra
Today SIP2SIP and a live demo (Adrian)
Today “Project OP^2” (Saúl)
Tomorrow OpenSIPS tutorial (Adrian & Saul)

8. AG Projects
SIP Infrastructure Experts
What is SIP2SIP
SIP2SIP is a real time communications service for Audio,
Video, Presence, Chat, File Transfer and multiparty
conferencing based on SIP and related media protocols (RTP,
MSRP and XCAP).
user@sip2sip.info

9. AG Projects
SIP Infrastructure Experts
SIP Protocol
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SIP stands for 'Session Initiation Protocol', an IETF standard
described in RFC 3261. SIP is an Internet application-layer
control protocol that can establish, modify and terminate
multimedia sessions such as Internet telephony calls (VoIP).
Media can be added to (and removed from) an existing
session
SIP allows the endpoints to negotiate and combine any type
of session they mutually understand like Audio, Video, Instant
Messaging (IM), File Transfer and provides a generic event
notification system with real-time Publications and
Subscriptions about state

10. AG Projects
SIP Infrastructure Experts
SIP Protocol mechanics
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INVITE mechanism, media agnostic, any type of
media supported by end-points (not just VoIP)
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Subscribe/Notify asynchronous mechanism with
XML payloads (Presence, Dialog-info, MWI)

11. AG Projects
SIP Infrastructure Experts
SIP Protocol features
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Portable Internet address (not tied to geography)
Any media possible using Offer/Answer model (SDP)
RTP media (audio, video)
MSRP media (chat, file transfer)

12. AG Projects
SIP Infrastructure Experts
SIP Protocol Addressing
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SIP Address example: user@domain
Can be the same as Email or XMPP address
Phone numbers can be mapped to SIP using ENUM

13. AG Projects
SIP Infrastructure Experts

14. AG Projects
SIP Infrastructure Experts
What is SIP2SIP
SIP2SIP is a real time communications service for Audio, Video,
Presence, Chat, File Transfer and multiparty conferencing based
on SIP and related media protocols (RTP, MSRP and XCAP).
user@sip2sip.info

15. AG Projects
SIP Infrastructure Experts
What SIP2SIP offers
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A publicly reachable SIP address user@sip2sip.info
Works with any SIP device (phone, soft client, PBX)
Works behind NAT
A free SIP client (Blink for SIP2SIP)

16. AG Projects
SIP Infrastructure Experts
First iteration of SIP2SIP
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Started in 2004 with UDP signaling and audio calls
Testbed for SIP Express Router
Free SIP address

17. AG Projects
SIP Infrastructure Experts
SIP2SIP Timeline
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Added MediaProxy NAT traversal
Added Voicemail and Voice to Email
Added Chat and File Transfer (MSRP protocol)
Added PSTN termination
Added ICE NAT traversal

18. AG Projects
SIP Infrastructure Experts
SIP2SIP Timeline
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Added Presence (SIMPLE and XCAP)
Added TLS support (encryption)
Added multiparty conferencing
Federation with XMPP domains
User your own Internet domain

19. AG Projects
SIP Infrastructure Experts
Usage (2010)

20. AG Projects
SIP Infrastructure Experts
Today’s Usage

21. AG Projects
SIP Infrastructure Experts
Building SIP2SIP
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SIP Servers (SER, OpenSER and now OpenSIPS)
Media relays (RTP Proxy then MediaProxy)
Presence Policy (OpenXCAP)
Databases (MySQL moving to Mongo DB)
Accounting (FreeRadius, Call Control, CDRTool)
Scalability layer (Heartbeat then SIP Thor)

22. AG Projects
SIP Infrastructure Experts
OpenSIPS
• SIP Proxy (routes SIP packets)
• SIP Registrar (end-points are reachable)
• Presence Agent (for presence)

23. AG Projects
SIP Infrastructure Experts
MediaProxy
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Relay for RTP media
Audio and video
Codec agnostic
ICE friendly

24. AG Projects
SIP Infrastructure Experts
MSRP Relay
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Relay for MSRP media
Chat Sessions
File Transfer
Screen sharing

25. AG Projects
SIP Infrastructure Experts
CDRTool
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Rating engine
Accounting
User portal

26. AG Projects
SIP Infrastructure Experts
Call Control
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Prepaid engine
Call Limits
Anti fraud

27. AG Projects
SIP Infrastructure Experts
Asterisk
• Voicemail and Voice to email
• Various telephony integration tasks

28. AG Projects
SIP Infrastructure Experts
SylkServer
• SIP Application server
• Multiparty multimedia conferencing
• XMPP gateway (for chat, audio, presence)
• Voice prompt playing

29. AG Projects
SIP Infrastructure Experts
SylkServer

30. AG Projects
SIP Infrastructure Experts

31. AG Projects
SIP Infrastructure Experts
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What is Privacy
Whom and when I communicate with (Signaling)
What and how I communicate (Media)
Encryption and Identity management

32. AG Projects
SIP Infrastructure Experts
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Privacy Stakeholders
Server based privacy (THEY know too)
Client based privacy (only YOU know)

33. AG Projects
Why should I care about privacy?
SIP Infrastructure Experts
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If you have nothing to hide you should not worry (big
government mantra). Returns FALSE.
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Who says the above is your nemesis (ask any one
who lived in a communist collectivist regime)
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Yes, you should care about your privacy. If your
privacy is not respected, it is a matter of time until all
your personal freedoms are taken away

34. AG Projects
SIP Infrastructure Experts
Should I Trust the Cloud?
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Don’t trust ANY server in the cloud
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GB per month of free storage but who owns my
data?
Privacy is COMPROMISED ‘by design’
All signaling information is known for routing and
accounting purposes

35. AG Projects
SIP Infrastructure Experts
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Encryption
Parties must exchange some keys
The keys are used to encrypt and sign the data
Exchanging the keys is key to this process

36. AG Projects
SIP Infrastructure Experts
Symmetric Key algorithms
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Same key used by both parties
Same key is used for encrypt and decrypt
Protects integrity but does not guarantee identity

37. AG Projects
SIP Infrastructure Experts
Asymmetric Key algorithms
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Each party has a public/private key pair
Public key is used for encryption
Private key is used for signing and decryption

38. AG Projects
SIP Infrastructure Experts
Encryption and Privacy tools
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zRTP for audio and video (roadmap for Blink)
OTR for chat (now available in Blink)

39. AG Projects
SIP Infrastructure Experts
Live Demonstration
• Blink SIP Client on SIP2SIP
• SylkServer multiparty conferencing
• Federation with XMPP Gmail

40. AG Projects
SIP Infrastructure Experts
Adrian Georgescu
ag@ag-projects.com
@agprojects