VoIP Telephony and You: A Guide to Design and Build a Resilient Infrastructure for Enterprise Communications Using the VoIP Technology (English Edition)

By Rashmi Nanda

‘VoIP Telephony and You’ introduces you to new and advanced ways of communicating over traditional telephony realms. Telcos use public internet private IPs for this long-distance voice communication in the Covid era.
This book describes how VoIP encompasses the capability to encode and deliver content in real-time across digitized networks. In this book, you will learn about VoIP regulations, VoIP hardware and software, video conferencing servers, SWOT analysis of Telcos, switching technology. You will also learn about the TCP/IP, market, Economics model, business model, and technology models. You will learn how to eliminate echo by understanding the various interfaces of VoIP and a number of digital protocols.This book will also provide you with a solution to design and maintain communication systems that can be used reliably in the Covid-19 times. This book includes several best practices and security measures to secure conversations by use of surveillance methods and VoIP security provisions.

• Language: English
• Publisher: BPB Online LLP
• Release date: May 10, 2021
• ISBN: 9788194837725

Book preview

CHAPTER 1

Introduction to Voice Over Internet Protocol

Introduction

Voice over Internet Protocol (VoIP) applications are multi-faceted with multimedia and voice-based telecommunication facilities. Among these, the successful market segments are standardization, infrastructure management, regulation, bandwidth and Quality of Service (QoS) . VoIP gateways are interfaces between Public Switched Telephone Network (PSTN) and IP networks, which moves data across a Local Area Network (LAN) through router and interfaces. The worldwide marketing of VoIP gateways reaches 7 billion dollars by 2020. VoIP gateways are implemented by methods like PC-based servers, router-based voice modules, and voice modules by concentrators. The VoIP equipment are IP phones, which belong to IP protocol functions having connection to the PSTN. Fax over IP (FoIP) is much better than fax because there is no real-time transmission.

Structure

In this chapter, we will cover the following topics:

VoIP introduction

VoIP regulation

VoIP methods

VoIP equipment

Objective

The first chapter deals with methodologies related to VoIP regulation, VoIP equipment, and introduces the various functionalities that enable the successful implementation of VoIP in our daily lives. Among these, the successful market segments are standardization, infrastructure management, regulation, bandwidth, and QoS. This is an introductory chapter, which walks us through VoIP.

VoIP Introduction

VoIP has acquired too much of attention recently because of numerous reasons. The most notable reason is that it possesses the potentiality for significant cost reduction of international and long-distance communication of voice. It introduces totally enhanced and new communicating ways. The following figure 1.1 shows how the basic VoIP system works:

Figure 1.1: VoIP

Fundamental VoIP applications are multimedia, voice, data and fax. "Voice traditionally has suggested telecommunications of voice alone. But, Voice over IP" is the generalized term used toward all realms of traditional telephony, with further applications offered over IP private and over public internet networks. The result is that the real-time information, fax, and multimedia services are regarded as VoIP sub-segments.

VoIP had a difficult beginning, partly due to the limitations that were technological and partly because of slower acceptance of newer technology characterized of being of poor reliability and quality. Improvements technologically with stronger public demands for low tariffs of phone result in the widespread VoIP marketing acceptances.

The services of VoIP are rapidly becoming a practical alternative to old services of telephony. PSTN services regulated by the government artificially with high price have been left vulnerable due to stepping in of these newer technologies. Quality and different VoIP challenges are addressed with worldwide booming in the usage of the internet, making it a conceivable substitute, resulting possibly in an integration predicted longer of information and voice networks. The following figure 1.2 shows a VoIP gateway with PSTN and IP phones:

Figure 1.2: PSTN, IP Phone, VoIP Gateway

The current VoIP technological applications are focused primarily around alternated service of long-distance voices. The providers of incumbent services recognize opportunity of VoIP as telcos of next generation and non-traditional givers of a service.

Voice over packets is researched since 1980s and 1970s, but the real VoIP developments had not begun till 1995. VocalTec, which is a firm in Israel, initiated IP telephonic market in year 1995 together with software allowing voice connections among 2 PCs over network based on an IP. Numerous packages started emerging, and in year 1997, Delta Three launched the first service of phone-to-phone for commercial use. The following figure 1.3 depicts an IP telephony system:

Figure 1.3: IP Telephony

There are current segments and niches of market where VoIP does prevail, but there are key obstacles to be overcome prior to it becoming successful mass market-wise. This includes bandwidth, regulation, network and infrastructure management, standardization, and QoS.

VoIP regulation

Regulations of VoIPs are largely questionable. Telephonic services traditionally have been regulated heavily. Numerous governments do operate on monopolies of telecommunications, with deregulation observed nowadays in others (1998 in lots of the EU and 1996 in the US).

Many government policies (in both developing and developed nations) toward the Internet have encouraged competition and growth by adoption of attitude of laissez-faire. The internet’s rapid development largely has been because of a lack of regulatory intervention. The introduction of most regulation forms truly retards internet innovation, thereby creating a barrier for entry for start-up organizations. Operators stand to get profit from this because they have cherished the monopoly position for numerous years. Both the European Commission and the Federal Communications Commission (FCC) welcome this provision to force down international tariffs of phone. The constraints of regulations related specifically to the internet put newer entrants at a severe disadvantageous place, in turn assisting continued overpricing of international and longer-distance telephonies. So, the regulation of telecoms generally has advantages for smaller providers of VoIPs. The following figure 1.4 shows the basic structure of a VoIP software:

Figure 1.4: VoIP Regulation and Software, H.323

The main barriers to change telephone companies for consumers are to convert numbers of phone and associated inconvenience. Portability of number allows customers to manage numbers while changing industries. When VoIP of phone-to-phone becomes commonly placed and convenient, the abilities for offering VoIP total services with no conversion of phone numbers work toward the advantage of small providers.

With a local loop of high-speed technology, the introduction ability for accessing local loops becomes important for providing competitive services. Regulation results in unbundling of local loops in a few European countries, the US, and Hong Kong. Recently, in 1999 July, BT did order open-up of their local loop. This gives a high-speed accessibility provision opportunity to those providers that are small.

There is a impediment of growth and sustainability which caused huge ethos of disappointment for Telecom companies. Telcos does not wish to obliterate a profitable business that exists to bank on regulation while assuming VoIP threat for petering out like Internet Telephony Service Providers (ITSPs) becoming classified such as provider of voice telephones. Many others have no desires for investing a solution of VoIP till its technical troubles are overcome. The following figure 1.5 shows an ITSP.

Figure 1.5: ITSP

Data services that are enhanced are the ones having an economic provision by givers of independent services (non-facility-based service providers) to have competition with networking provider as longer as they gain accessibility to networks. An example of service enhanced is the provision of contents for premium rating service and retail internet service provision. Internet Service Providers (ISPs), Enhanced Service Providers (ESPs), and ITSPs generally are not subjected to longer-distanced charge of accessibility. Telcos urges regulatory positions for changing. ITSPs become competitive increasingly with telcos, so they argue for identical classification. Simultaneously, there is a difficulty for differentiating between varied internet traffic types. So, the methods for levying accessibility costs on ITSPs do seem impossible. The following figure 1.6 captures the very essence of ISPs for internet users:

Figure 1.6: ISP

The following figure 1.7 shows the ESPs data packets:

Figure 1.7: ESP

The European Commission defines voice telephony as "commercial provisions for publics of speech switching and direct transportation in real-time among termination points of public switched networks in turn enabling whichever user to utilize connected equipment for such network termination points for communicating with different points of termination."

So, the following conditions should be met:

Services offered should be part of commercial offers. Services are provided to all members of the public. Services involve speech and direct transport in real time. Services are given between termination points of public-switched networks in fixed telephonic networks. VoIP lacks a few of these factors, notably the most being transmission in real time. This falls short of traditional telephony, which is not fully transparent, reliable, and ubiquitous.

VoIP generally is not an available service of voice transmission, but it is an application available for the ones who already subscribe to the basic package of the internet. The European Commission does not force ITSPs for the payment of accessibility charges because of such closed user group offerings. VoIP is seen as an effective method for introduction of competition because of restriction of telephones in Europe.

Additional points suggested is that added movements of regulation affects industry of VoIP. Such things include rules of entry and requirements of market entries:

Providers are not subjected to required factors of market entry and restrictive licensing, which have applicability to varied providers of telecommunications because of the classification of many internet services as non-voice or non-basic services. Regulators begin to impose licensing, registration, or various ITSP requirements because VoIP becomes a serious competitor for older telephonies. Such processes are time-consuming, thereby increasing time-to-market of newer entrants.

If ITSPs have been classified as a carrier of basic service of voices, there are requirements for having compliance with routing rules and restrictions. This restricts those services that in turn bypass the systems of accounting. But, with provision of complex internet topology, there are virtual impossibilities for monitoring packets that are individual with imposition of rules of routing on them.

VoIP methods

VoIP had been initially dismissed easily. Software of client provided poor quality that resembled a CB radio, and that allowed only party numbered one to speak in one instance. Communicating party numbered two needs to have an online service together with compatible running software on their PC. But, potentiality for these services was visualized by vendors like Microsoft, Intel, and Netscape. All of these launched items of VoIP in the year 1996. Till this time, two of the internet backbone and computing power capacity had been improved. Much better quality of voice had got VoIP availability. Simultaneously, communications of VoIP received standardization of the International Telecommunications Union (ITU). By 1997, commodities based on standards had achieved presence. The basic necessities of all earlier products of VoIP were users who at all ends had a connection of the internet. VoIP gateway development has modified this such that phone-to-phone and PC-to-phone calls could be made. This removes one among most core barriers to broad acceptance in the market. With installed gateways, there is no need for users to have special software, PCs, or even internet connection for placing calls mainly routed over the public internet. Gateways do allow users for circumventing PSTN with its tariffs, utilizing internet for variable quality voice communications and for significant reduced prices.

Numerous newer operators and vendors/manufacturers of equipment have emerged ever since the release of internet phone. The first scalable and robust commodity of VoIP and VoIP initial service had been given by Delta Three in the late 1995. Client software has been presently supported by many operating systems like Mac, Windows, and UNIX.

VoIP’s original form is PC-to-PC telephony. Both users must be online prior to whichever setting up of connection and usage of compatible multimedia computers and software. This does not have practicality for tariffs separation or regulation of such VoIP forms because it is critical with the probability of being counterproductive and trying for distinguishing the bits of audio from different bits. There are difficulties for differentiating among the full-duplex real-time communication and time-insensitive store and forward information. Unless the internet has been regulated in wholesome, there are no feasibilities for regulating this VoIP form.

Telephony of PC-to-phone arose as the PSTN-to-IP and IP-to-PSTN gateways established their presence. Gateways compress and packetize voice traffics from PSTNs, placing it on the network of IP and decompressing and assembling traffic in varied directions. The following figure 1.8 shows the gateway between PSTN and IP:

Figure 1.8: PSTN-IP Gateway

Regulation of the VoIP of PC-to-phone is a difficult process. Call originators pay no accessibility charges because, to service providers, it looks similar to a PC-to-PC call. This reduces the fees of accessibility greatly, as the originator pays usually nearly two-thirds of total charge of access. At the end of termination, the provider of service gives termination service both to long-distance and local callers, but they cannot know where particular call of VoIP has been originated, with spurring of troubles with tariffing and regulation. With VoIP of phone-to-PC, there have been no access fees at the point of termination because originators do not know where calls terminate. The following figure 1.9 deals with PC-to-phone communication by VoIP.

Figure 1.9: PC to Phone Communication

VoIP of phone-to-phone does eliminate the need for PC totally, by using internet for carrying voice in between two gateways. VoIP calls of phone-to-phone now offer great quality when compared with PC-to-phone and PC-to-PC calls of VoIP because PC-to-PC offers over one dedicated network of IP. There are breakouts to PSTN at two ends, but because the originator is not aware of call termination and vice-versa, problematic factors regarding access fees and regulation exist.

FoIP is superior to fax, which is traditional, because it does have no requirement for real-time transmission. Fax transmission is associated traditionally with PSTN and is not varied from sending whichever different file. Messages of a fax have an ability to absorb delays with the retransmission of packets with no negative impacts on the final data received. Conferencing of multimedia does involve data, video, and real-time voice combination transmission over the internet. Although standards have been emerging, this shall lag behind various applications of VoIP due to substantially great bandwidths needed for multimedia application.

VoIP equipment

For providing solutions of VoIP, varied networks of IP and internet must seamlessly interface with PSTN by means of gateways. Such gateways are one among the key revenue areas for vendors of VoIP equipment. IP networks must acknowledge schemes of prioritization and reservation of resource needed for guaranteeing QoS for dependent data of delay. The hardware needs to give services of VoIP ranging from standardized machinery of networking like switches and routers to IP phones and to gateways.

IP phones

Phones belonging to IP functions like regular phones operate, but in place of having connection with PSTN, they have a connection with IP messaging networks with the transmission of voice information by virtue of IP packets.

IP phones presently are too expensive, and to use VoIP is inconvenient and cumbersome. Old telephones are simpler to utilize and cheaper to buy, and costs that are marginal are closer to zero, in turn allowing prices to have huge reductions. IP phones (and VoIP generally) must be developed further for ways of easy usage and decreasing prices, prior to their invasions in space of old telephonies.

Till date, IP telephones have a difficulty for average users’ adaptation such that interfaces are inconvenient. To create ample familiarity with necessary features of older telephony to IP environments, moving toward IP networks and PSTNs seamless integration has started.

In 1998, Selsius was purchased by Cisco. It introduced phones providing all the functionality that is found in traditional phones with a direct connection to IP networks. There is a shift in industry of telephonic equipment, suggesting newer opportunities for Private Branch eXchange (PBX), and vendors of telecom services. Theoretically, IP telephones have operations as phones that are old, while having ability for adding newer capabilities. The following figure 1.10 tells us about the PBX:

Figure 1.10: PBX

IP Courier Ethernet Phone of Nokia does provide functionality of PBX (like features of call controlling and multiple lining appearances) without PBX. It is an Ethernet telephone together with familiar interfaces linking directly to IP networks. It supports telephonic features like transfer of calls, caller ID, forwarding of calls, and waiting of calls.

IP Shuttle product of Nokia is a premises device of customers, allowing standardized telephones to become plugged into network of IP. It aims at those environments that are residential and are specifically designed to serve newer data and voice services offered by organizations of telephones and industries of cables.

Siemens released (April 1999) an IP telephone with capability that is enhanced –new interface, message with regard to unanswered calls, and ability for name retrieval and address of IP caller retrieval. Their HiNet LP 5100 IP telephones cost 425 dollars, but the price might fall rapidly.

Ericsson has released Doubler telephone that allows the use of a virtual line of telephone, enabling a user to get calls of phone (over IP) without logging off to the internet. Voice traffics are carried over IPs between the gateway and the PC of the user, with rest of the calls carried on PSTN. Thus, QoS has direct dependence on the speed of user connection and on trafficking that is generated by them.

Gateways of VoIP

Gateways act like an interface in between IP networks and PSTN. When VoIP calls are made, there are breakouts usually to PSTN at all ends, for last and first legs of links, with internet or different IP networks utilized for trunk connections.

Gateways accept fax machine or traditional phone connection determining termination calling points and deciding what is the cheapest and best way for routing calls (that is how much of links are over PSTN).

Gateways originally were aimed at customers of business, and they increasingly were aimed at carriers and ISPs desiring to offer services of VoIP as competitive advantages. With rising scalability opportunities, there are supplying items to providers of services instead of small enterprises.

Gateways do not interoperate correctly; users are left to confine to networks of their providers or the ones formed through the partnerships. H.323 likely becomes the protocol of standardized interoperability, and such standardization happens soon (by end of 2000) because of pressure from the service providers.

Motorola has collaborated with Vsys (June 1999) for developing VoIP gateways on the basis of Vswitch VoIP solutions for intelligent applications of network. Vswitch is a software product based on UNIX, which provides an interface both for Signaling System no. 7 (SS7) and H.323 standards to assist fax, voice, and message. Its capabilities involve an advanced intelligent service of network like single-stage dialing and free phone numbers and provisioning and billing. The item must be available commercially