iPBX White Paper
Transcript of iPBX White Paper
-
8/14/2019 iPBX White Paper
1/12
Surf Communication Solutions, Ltd. Tavor Building P.O. Box 343 Yokne'am 20692 Israel
Tel: +972 (0)73 714 0700 Fax: +972 (0)4 959 4055 e-mail: [email protected] www.surf-com.com
Videoconferencing, Video Mail, IVR and Mobile ServicesProvided by iPBX Technology
Introduction
Private branch exchange (PBX) systems have traditionally connected private enterprises to
the public switched telephone network (PSTN) using circuit-switched communications. iPBX(or IP PBX) systems, which use the Internet Protocol (IP) to carry calls over packet-switched
networks, have become increasingly popular in recent years. iPBXs account for a significant
majority of current annual PBX installations. IP based private branch exchange are
projected to further dominate the videoconferencing, video mail, IVR and mobile markets in
the coming years.
While the move toward iPBX systems represents a clear trend, the ongoing integration of IP
within PBX architecture can be viewed as more of an evolution than a revolution. Only
recently have enterprises begun to deploy advanced multimedia iPBX systems, empowering
a wide array of multimedia services and applications such as videoconferencing and mobileservices, take full advantage of the iPBX capabilities. This paper examines the various
stages of PBX architecture development on the road to multimedia iPBX, selected service
scenarios enabled by multimedia iPBX, and multimedia iPBX extensions that power
implementation of next-generation systems.
http://en.wikipedia.org/wiki/PSTNhttp://surf-com.com/media-processing-products/voipchips.htmlhttp://surf-com.com/media-processing-products/voipchips.htmlhttp://en.wikipedia.org/wiki/PSTN -
8/14/2019 iPBX White Paper
2/12
Multimedia iPBX: Moving Beyond Voice Services
Evolution of PBX Architecture
Phase 1: Traditional PBX
In the first stage, traditional PBX systems connected time-division multiplexing (TDM)
equipment and phones only to the circuit-switched PSTN network. Initially deployed toachieve substantial cost savings on intra-enterprise phone calls, PBXs became more popular
after offering a wide variety of services unavailable in the operator network including call
forwarding, extension dialing, auto dialing, and call waiting.
Figure 1: Traditional PBX Architecture
The PBX at the enterprise connects to the PSTN via E1/T1 trunk lines, and to the enterprise network
using traditional TDM circuit-switched technology.
Phase 2: VoIP+PBX
In the second phase of the PBX evolution, enterprises typically added a voice-over-IP (VoIP)
gateway to operate along side the existing circuit-switched PBX. The new VoIP gateway
enabled packet-switched communications between the enterprise and IP network, while the
previously deployed PBX continued to support traditional circuit-switched communications.
In this phase, VoIP was the main service added to those services already offered in the first
PBX phase, and was typically adopted to reduce the enterprise's communication costs.
Surf Communication Solutions, 2008 Page 2 of 12
-
8/14/2019 iPBX White Paper
3/12
Multimedia iPBX: Moving Beyond Voice Services
Figure 2: PBX + VoIP Architecture
The addition of a VoIP gateway enables the enterprise to connect to the IP network for cost-
effective VoIP services.
Phase 3: Hybrid iPBX
The third phase of PBX architecture development introduced the hybrid iPBX systems that
are predominantly IP in nature, but still support circuit-switched communications to the
PSTN. This phase represents the current status of the PBX evolution, and most iPBX systems
sold today are in fact hybrid, rather than all-IP, systems. Another major current trend is the
adoption of open-source iPBX solutions such as Asterisk, a leading open-source telephony
engine and tool kit.
Despite the advanced capabilities of hybrid iPBX systems, they are still used primarily for
voice services and applications such as peer-to-peer communications, interactive voice
response (IVR), and voicemail.
Surf Communication Solutions, 2008 Page 3 of 12
-
8/14/2019 iPBX White Paper
4/12
Multimedia iPBX: Moving Beyond Voice Services
Figure 3: Hybrid iPBX Architecture
The hybrid iPBX, with an integrated VoIP gateway card, represents the current status of PBXevolution.
Phase 4: Multimedia iPBX
The next phase of PBX development can be called "multimedia iPBX." In this phase,
advanced iPBX systems will empower a wide range of attractive multimedia services and
applications such as videoconferencing, video mail, IVR and mobile services. Before we fully
examine the architecture of multimedia iPBX, we will review a number of key multimedia
service scenarios enabled by iPBX.
Multimedia User-Experience Scenarios
Scenario #1: Videoconferencing
The CTO has a new idea for a product and wants to receive quick feedback from various
colleagues. He invites selected local managers into the conference room for an impromptu
meeting. Participants then decide to establish an immediate off-site videoconferencing
session with the chief design engineer, who is located at a different office, and the VP of
sales, who is reached on his mobile phone sitting on a bench at the train station.
Surf Communication Solutions, 2008 Page 4 of 12
-
8/14/2019 iPBX White Paper
5/12
Multimedia iPBX: Moving Beyond Voice Services
Figure 4: Multi-Point Videoconferencing Scenario
This illustration depicts a multi-point videoconference including a chief design engineer at a remote
office, a VP of sales in transit, and a CEO and local team in a conference room.
Videoconferencing represents the use of audio and video telecommunications to enable
real-time meetings among numerous participants at different locations. Videoconference
meetings can range from simple conversations between two or more people at two locations
(point-to-point), to complex conferences connecting multiple users at multiple locations
(multi-point). Until now, videoconferencing required utilization of dedicated, identical and
expensive videoconferencing equipment at each location. Preplanning of each conference
was required due to the equipment set up requirements prior to each session.
Now, it is possible to avoid these drawbacks and create a multi-purpose, high-quality and
inexpensive videoconferencing system, as part of an IP-based enterprise telephony system.
The iPBX can serve as a videoconferencing bridge simply by adding video capabilities to the
existing PBX. Enterprises can utilize the same end-user equipment such as desktop video
phones, soft desktop clients and mobile handsets to establish spontaneous point-to-point
or multi-point video conferences. Common videoconferencing applications include corporate
meetings, remote education, legal consultations and testimonies, and long-distance
medicine.
Surf Communication Solutions, 2008 Page 5 of 12
-
8/14/2019 iPBX White Paper
6/12
Multimedia iPBX: Moving Beyond Voice Services
Figure 5: iPBX with Integrated Videoconferencing Capabilities
iPBXs enable multi-purpose, high-quality and inexpensive videoconferencing systems as part of an IP-
based enterprise telephony system.
Scenario #2: Interactive Voice and Video Response (IVVR)
A paramedic is tending to an injured driver at the scene of a traffic accident. Prior to
administering aid or transferring the patient, he decides to consult with medical staff in
the hospital emergency room. He uses his mobile phone to call the hospital and reaches its
IVVR portal, a pre-programmed, interactive directory is used for direct calls within theorganization. The paramedic chooses the option to consult with a specialist and switches to
video mode. He then uses the camera on his mobile phone to relay visual information
about the patients injuries, and receives instructions from the specialist. After entering
the ambulance, he then navigates back within the IVVR portal to the emergency room to
update the receptionist with their estimated time of arrival.
Surf Communication Solutions, 2008 Page 6 of 12
-
8/14/2019 iPBX White Paper
7/12
Multimedia iPBX: Moving Beyond Voice Services
Figure 6: IVVR Scenario
An IVVR session with a paramedic using a mobile phone camera to relay information to a hospitalemergency room for review, and then receiving instructions from a physician.
Interactive voice response (IVR) is a highly prevalent technology that allows users to access
and receive pre-recorded audio messages over their phone. Adding a video dimension, next-
generation interactive voice and video response (IVVR) allows callers to view menu choices
or video presentations, access live sources (such as the medical expert in the scenario
depicted above), and relay visual information.
IP-based IVVR systems streamline calls to enhance the customer experience and reduce
costs associated with human agents and large call volumes. Voice-only IVR is migrating to
video-enabled IVVR now that a critical mass of video-ready mobile handsets are on the
market, and operators are increasingly appreciating the improved user experience and new
revenue opportunities offered by video. Common IVVR applications include contact centers
(e.g. telephone banking, credit-card transactions, reservation systems), televoting for TV
programs, mobile and landline content ordering (e.g. games, ringtones, weather forecasts,
adult entertainment), and organizational portals.
Surf Communication Solutions, 2008 Page 7 of 12
-
8/14/2019 iPBX White Paper
8/12
Multimedia iPBX: Moving Beyond Voice Services
Scenario #3: Video mail
Enterprises typically update their employees regarding company activities via periodic on-
site meetings. The larger the company the more difficult it is to arrange meetings with
100% attendance due to, off-site meetings, vacations and sick days. Using video mail, the
company can ensure that the content of such meetings will reach all employees and remain
easily accessible. The live meeting is recorded with a standard video camera or webcam,
with the resulting file stored on the network. Employees who were not present at the
meeting, or those in attendance who want to review certain parts of the presentation,
receive the video clip as a video mail directly to their computer or mobile phone.
Figure 7: Video mail Scenario
Illustration of a video mail scenario where an ill employee at home views, via his mobile phone, a
recording of the CEO's presentation at an annual company meeting.
Video mail, which is an extension of voicemail or email with an added video dimension, can
be sent to recipients' desktops or mobile handsets. From the sender's perspective, videomail enables a new level of rich-media content and personalization. From the recipient's
perspective, it ensures that messages will never be lost and allows convenient viewing of
received video clips. From the enterprise perspective, video mail represents another
channel for effective intra-organizational communications. From the service provider
perspective, video mail creates additional revenue streams via increased service adoption
and new advertising opportunities. Given the growing penetration of broadband Internet
access, mobile Internet and video-enabled handsets, video mail is expected to become
increasingly prevalent in the coming years.
The iPBX can support a wide variety of video mail services. Common video mail applicationsinclude personal or video messaging over landline, wireless and mobile networks.
Surf Communication Solutions, 2008 Page 8 of 12
-
8/14/2019 iPBX White Paper
9/12
Multimedia iPBX: Moving Beyond Voice Services
Multimedia iPBX Architecture Design
Multimedia iPBX systems introduce a new set of functionality to leverage IP capabilities and
enhance productivity. Their goal is to enable easier and enriched communications while
keeping costs at a minimum.
When designing an advanced iPBX, telecom equipment manufacturers require converged
multimedia communications, multiple network bridges, and support for a variety of user
terminals (3G, IP, PSTN), as well as back-office integration for easier access and
management.
Figure 8: Multimedia iPBX Internal Architecture
The multimedia iPBX incorporating signaling, media processing and storage subsystems empowers
a wide array of multimedia services that take full advantage of IP capabilities.
A multimedia iPBX system is a self-contained system featuring a signaling subsystem, a
media processing subsystem and a storage subsystem. The signaling subsystem is responsible
for all call control interaction between the iPBX and external phones and other entities
whether IP phones, POTS phones, fax machines, etc. The signaling subsystem is typically
implemented on a general-purpose host processor, and handles signaling protocols such as
SIP, H.323, ISDN-PRI/BRI, and a variety of analog signaling schemes.
The media processing subsystem is responsible for any required processing on the mediapayload, such as:
Surf Communication Solutions, 2008 Page 9 of 12
-
8/14/2019 iPBX White Paper
10/12
Multimedia iPBX: Moving Beyond Voice Services
Physical interface transformation from E1/T1 and analog interfaces in the circuit-switched network into Ethernet in the IP network
Transcoding Conversion from circuit-switched voice/fax to packetized voice/fax Echo cancellation Conferencing Tone and other telephony event detection/generation/suppression Security Playing and storing prompts and other forms of media Routing and more
The media processing subsystem is typically handled by DSPs and other physical interface
components such as framers and PHYs.
The storage subsystem is responsible for storing prompts and recorded voice/video contentof a voice/video mailbox application. In compact iPBX implementations, the storage
subsystem resides on a local storage device, while in scalable and large-scale systems it is
often stored on external servers.
The iPBX "control application"is an application that controls all three entities to enable a
large multitude of services from simple peer-to-peer voice calls to more sophisticated
services such as IVVR and multi-party videoconferencing.
Additional Multimedia Services
As depicted by the aforementioned user-experience scenarios, multimedia iPBX empowers
an array of compelling services that go well beyond traditional voice services. Additional
key multimedia services that can be offered over multimedia iPBX include:
Dual-Mode Handset
Many current mobile phones are equipped with dual-mode operations, allowing them to
function on both cellular and IP networks. An iPBX can be used to capitalize on this dual
functionality and reduce intra-organizational communication costs. In addition to supporting
standard IP codecs such as G.711 and G.729, an iPBX can support cellular codecs such asAMR and EVRC. As a result, employees can operate their mobile phones like a WiFi device
within the enterprise via the internal network, saving on cellular connection charges. The
support and transition to mobile mode is seamless, so no change in usage habits is required.
Secure Voice
The American National Security Association (NSA) has adopted the IP-based V.150.1 ITU
protocol to ensure secure voice communications among government intelligence agencies.
Recently, several leading manufacturers have commenced production of telephone sets for
internal use that incorporate this protocol in order to transport secure voice traffic. For the
V.150.1 protocol to function, the PBX must serve as a gateway between the PSTN and IP
Surf Communication Solutions, 2008 Page 10 of 12
-
8/14/2019 iPBX White Paper
11/12
Multimedia iPBX: Moving Beyond Voice Services
network. iPBX architecture allows the inclusion of the gateway component within the PBX
framework, thereby streamlining the solution and reducing maintenance costs.
Multimedia iPBX ExtensionsManufacturers of multimedia iPBXs require high-density, low-cost and scalable multimedia
extensions that can be easily integrated into their systems. Surf Communication Solutions
offers media processing solutions that enable multimedia convergence while supporting an
easy migration path from voice to video.
SurfExpress/PCIeTM Media Processing Solution
SurfExpress/PCIe is a modular PCI Express form
factor DSP resource board for flexible yet heavy-
duty enterprise-grade multimedia processing. Theboard features a highly innovative patent-pending
design featuring the SurfDocker plug-in, allowing
it to carry up to four pairs of DSPs for a total of
eight DSPs per board. Providing 2 Gbit Ethernet
ports and a CT bus for additional TDM interfaces,
SurfExpress/PCIe is designed to meet the
requirements of VoIP enterprise-scale media
servers, iPBXs, media gateways, 3G-324M video
servers, MMSC content adaptation engines, and CTI applications.
Surf DSP-Level Media Processing Solutions
The Surf DSP-level family leverages Texas Instruments' C64xTM DSP
generation, and includes Surf DSP-12/24/82 based on TIs
TMS320C6412/24/82, respectively. Featuring cost-effective unmatched
processing power of varying densities (depending on the DSP model) and
Surf's patent-pending Open Framework design, the family allows
seamless integration of user-defined and proprietary algorithms. Each member of the Surf
DSP family provides a powerful, yet flexible computing environment for telecom
infrastructure equipment developers.
Surf Communication Solutions, 2008 Page 11 of 12
-
8/14/2019 iPBX White Paper
12/12
Multimedia iPBX: Moving Beyond Voice Services
About the Author
Avi Fisher, CTO, Director and co-founder of Surf Communication Solutions, maintains
extensive expertise in digital signal processing, embedded software and system
architecture. Author of several patents, he was the first contributor to the ITU V.150.1
standard for the relay of modem signals over IP. Avi Fisher holds a B.Sc. summa cum laude
and an M.Sc. from the Technion Israel Institute of Technology.
About Surf Communication Solutions
Surf Communication Solutions provides media-processing solutions that enable convergence
of voice, video and data across wireline and wireless networks. Surfs solutions are
predominantly utilized by media gateway developers, media server developers and IMSequipment manufacturers in the telecommunication infrastructure field to significantly
reduce time to market. For more information, visit www.surf-com.com.
Surf Communication Solutions, 2008 Page 12 of 12
http://www.surf-com.com/http://www.surf-com.com/