2. How Will You Be Developing Your Next Application? (SIP-01)
SIP vs. API
The last few years has brought a major change to the way that advanced applications are developed. Developers now have the choice between using standards-based SIP or traditional APIs. No one solution is ideal for every developer as choices about time-to-market versus solution cost must be balanced. By attending this session you will learn about a number of new options developers have when creating their applications, learn about some new protocols and discuss the pros and cons of each in real-world scenarios.
45 minutes
How Will You Be Developing Your Next Application? (SIP-01)

3. Competing methods

4. Development Building Blocks
Your Application
Compiled
XML
Graphical
C/C++
Java
VoiceXML
API
NETANN
MSCML
MSML/MOML
Drivers
SIP
Hardware

5. API – What is it? If all else fails, refer to Wikipedia: API
An application programming interface (API) is a source code interface that a computer system or program library provides to support requests for services to be made of it by a computer program.

6. Legacy API Architecture
Application
Proprietary
Proprietary
API
API
Proprietary
Proprietary
Device Driver
Device Driver
H.100
T1 Interface
Hardware
Resource
Hardware
PSTN

7. API Development Key Attributes: Powerful Feature Rich Highly Efficient
Highly Complex
Slow to Develop
Hard to Debug
Proprietary (mostly)

8. Development Building Blocks
Your Application
Compiled
XML
Graphical
C/C++
Java
VoiceXML
API
NETANN
MSCML
MSML/MOML
Drivers
SIP
Hardware

9. SIP – What is it? Wikipedia: SIP
The Session Initiation Protocol (SIP) is an application-layer control (signalling) protocol for creating, modifying, and terminating sessions with one or more participants. These sessions include Internet telephone calls, multimedia distribution, and multimedia conferences. (cit. RFC 3261).

10. SIP – Where does it fit? SMTP HTTP RTP SIP TCP UDP IP Ethernet PPPL5 L4
TCP
UDP L3 IP L2
Ethernet
PPP
Copper
Fiber
Wireless L1

11. SIP Development Key Attributes: Open Standard Interoperable
Easy to Debug
Inefficient
Moving Target
Slow to evolve

12. Service Creation Environment
SIP Architecture
Application
Service Creation Environment
SIP
SIP Protocol Stack
LAN
Media
Gateway
Resource
Media Resource
PSTN

13. Two Classes of Resources
Media Gateways
Provide connectivity to existing TDM infrastructure
90% + of installed base is still TDM
Media Resources
IVR – Play / Record / DTMF
Conferencing
Fax
Tone Detection/Generation
Announcements
Transcoding

14. Speeds Development Time
Customer A:
Just over 3 Man-years to integrate and test with a Legacy PCI Blade 3
PCI
Same customer using SIP based hardware, 88% less time to market! 2
Integration
Time in
Man-Years 1
SIP

15. Development Building Blocks
Your Application
Compiled
XML
Graphical
C/C++
Java
VoiceXML
API
NETANN
MSCML
MSML/MOML
Drivers
SIP
Hardware

16. NetAnn – What is it? NetAnn RFC 4240 as of December of 2005
Predecessor to MSCML.
Basic announcements
Simpler conference model (no control dialog)
Doesn’t provide for mid-call requests and responses.

17. MSCML – What is it? MSCML – Media Server Control Markup Language
RFC 4722 in November 2006
Provides “services” to users at an application level
Services specified in user part of URI.
For example – “Conf” service implies a star connection topology with a mixer at the center, or PlayCollect connects a “player” and a “dtmf-receiver” to the call
Conf, IVR (Play, PlayCollect, PlayRecord, FaxPlay, FaxRecord)
Command oriented protocol (vs scripted)
MSCML IVR syntax is modeled on the H.248 and MGCP
Includes the composite PlayCollect and PlayRecord functions

18. MSCML - Sample Example of a Play command:
<?xml version="1.0" encoding="utf-8"?>
<MediaServerControl version="1.0">
<request>
<play id="234">
<prompt>
<audio url="
<variable type="date" subtype="ymd" value=" "/>
<variable type="silence" value="5"/>
<variable type="duration" value="2"/>
</prompt>
</play>
</request>
</MediaServerControl>

19. MSCML Conferencing – Create

20. MSCML Conferencing – Play

21. MSML / MOML – What is it? MSML – Media Sessions Markup Language
Device Control Protocol that focuses on internal media server resources
SIP is normally concerned with the behavior external to the media server
Provides a mechanism for invoking MOML or VXML scripts.
Provides a mechanism for creating conferences and modifying their topologies.
Does not provide for IVR control
MOML – Media Objects Markup Language
MOML is a scripting languages that provides a defined set of useful IVR primitives: play, generate dtmf, recognize dtmf, record, recognize speech, and others
Primitives can be combined into groups, and multiple groups can be established concurrently. Lots of flexibility at the cost of complexity
It is a scripting language with an internal state machine, but only 2 primitives have state, and they only have 2 states (stop/go).
Absence of flow control limits scripts to functions rather than applications (eg VXML)
IETF Draft (no RFC)

22. MSCML vs MSML/MOML Application Level Services vs Device Control
MSML provides explicit internal connection topology.
MSCML provides predefined services with implicit internal connection topologies
Provides a less complex interface for 99% of what’s required.
Scripting
MOML provides a script execution capability to build composite functions.
State Machines within primitives are so limited as to be of little general use.
Requires a script execution framework.
MSCML provides defined composite functions
For example PlayCollect/Record provide integration between the Play and the Collect/Record functions. Much simpler for 99+% of use cases
No script engine required: provides performance advantages as well as simplicity

23. Who supports what?
MSCML / NetAnn
MSML / MOML

24. Media Control -Bottom Line
Neither MSCML nor MSML/MOML are likely to be the “Final Answer”.
Both rely on INFO messages which the IETF SIP arbiters do not like
Both will allow you to do what you need to get done
MSCML is our favorite:
Greater standards “coverage” (RFC vs not RFC)
Easier to use (Operates at application level vs device control)
More widely adopted
Better adapted to 3GPP MRF (IVR mapping to H.248 used in MRFC-to-MRFP)
Discussion is carried out in the “mediactrl” - Media Control BOF Discussion List
“Final Answer” likely 2 to 3 years out.

25. Will we need APIs and SIP?

26. How do they compare Capability / Feature API SIP+NetAnn SIP+MSCML
TDM Bus Switching (H.100)
Yes No
Industry Standard (RFC?)
Basic IVR
Complex IVR
Mixing/Recording
Simple Conference
Complex Conference Controls

27. The Future Expect many new applications to leverage SIP
With one of the media server control protocols
APIs will continue, but only for very complex apps.
Secret: our SIP and MSCML uses our API under the covers!
Expect continued refinement
of SIP and related media server protocols

28. Questions? ?

29. More information
Booth #115