ipbx white paper

8/14/2019 iPBX White Paper

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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


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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.

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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.



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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.



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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.



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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.



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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.



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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.



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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:



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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



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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.



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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.

http://www.surf-com.com/http://www.surf-com.com/

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