VoIP-Telecom_Oct10 by pengxuebo



VoIP and Traditional Telecom:
1 Minus 1 or 1 Plus 1?
With existing circuit-switched networks still in good shape, will telephony
service providers ever venture to replace them with IP-based networks? Not
likely. But VoIP definitely has its bundle of benefits, and can perhaps be used in
areas where legacy infrastructure does not exist, or to enhance existing telecom
services using facilities like SIP trunking

                                                                                         definition digital voice communica-
                                                                                         tion. It also brings with it a bundle
                                                                                         of other features such as convergence
                                                                                         with other IP-based communications,
                                                                                         scalability, low maintenance in the
                                                                                         long run, voice mail on email, three-
                                                                                         way conferencing, speed dialling, call
                                                                                         forwarding, simultaneous ring, call
                                                                                         waiting, caller ID, call return, caller ID
                                                                                         block, anonymous call rejection, ‘do
                                                                                         not disturb’ feature, last number redial
                                                                                         and more.
                                                                                             It is also quite easy to install and
                                                                                         use these days, whether for a corporate
                                                                                         or for an individual. “A PC, broadband
                                                                                         connection and an analogue telephone
                                                                                         adaptor (ATA), which the VoIP service
                                                                                         provider will offer to the customer as
                                                                                         part of the deal, is what one needs to
                                                                                         start using VoIP. There is no costly
   JaNaNI GoPalakrIShNaN VIkraM            The VoIP advantage                           infrastructure and with the ATA in
                                            “Technology-wise VoIP is better,             place, one can use his/her normal tel-

         oice over Internet Protocol        cheaper, dynamic, less resource-             ephone to make VoIP calls,” explains
         (VoIP) has been talked about a     intensive and more feature-rich. Or-         Srinivasan.
         lot—bouquets or brickbats, it      ganisational users can greatly benefit           One of the biggest benefits of VoIP
has had its share. From policy misun-       from end-to-end connectivity, while          is probably the portability that it offers.
derstandings to implementation hitch-       the initial investment in equipment          Since an IP address is what identifies
es, there have been and continue to be      and setup is also comparatively less in      each IP phone, the user can be reached
many thorns in its path. However, the       the case of VoIP. There is also a huge       at the same number regardless of where
truth remains that it is a winning con-     gap between the two when it comes            he plugs the phone in. While normal
cept that will endure the test of time.     to sound quality,” says Srinivasan S.,       telephones are permanently linked to the
    “The benefits of IP technology          founder and director of VIVA Com-            telephone lines, the ATA can be taken
will always outweigh that of the old        munications.                                 anywhere, and by simply attaching it to
circuit-switched technology. The                Simply put, the fact that VoIP           a normal telephone and an Internet con-
circuit-switched networks will eventu-      can work over existing broadband             nection, one can make VoIP calls, with-
ally be phased out. It is simply a matter   networks makes it a low-cost option,         out the roaming charges as in the case of
of how many years before the migra-         while the versatile nature of the Inter-     mobile phones. This makes the system
tion takes place,” comments Ashish          net protocol makes VoIP a multi-facet-       portable, flexible and cost-effective.
Sharma, vice president–marketing,           ed and unified communications tool.              In the long term, the scalability
Alvarion.                                       VoIP means more than just high-          of VoIP networks also proves to be a

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huge benefit. Sharma adds, “VoIP net-
works are very scalable, meaning they
                                                                 VoIP vs PSTN
can be expanded with relative ease                                                                                               ,
                                                                 When somebody refers to ‘traditional’ telecom as against VoIP he is likely to be referring
given they use standard interfaces. It is                        to dear old PSTN!
                                                                    Our nation’s telephone network, and that of most others for that matter, works over
also much easier to introduce new ser-
                                                                 what is known as the public-switched telephone network or PSTN. Some also call it the
vices over IP networks because of the                            plain-old telephone service (POTS)!
way the protocols are structured. Also                              There is nothing so plain about it though. It is a worldwide network of telephone lines,
from a maintenance and operational                               fibre-optic cables, microwave transmission links, cellular networks, communications
perspective, IP networks are much                                satellites and undersea telephone cables. This network is interconnected by switching
easier to handle.” Moreover, in order                            centres that enable telephones across the world to connect to each other using a uniform
to scale a traditional circuit-switched                          numbering system. The whole setup is based on circuit-switched networking—that is,
                                                                 a circuit or channel is established between the various nodes and terminals before the
network, additional lines would have
                                                                 users communicate, as if the nodes were physically connected with an electrical circuit.
to be added, but VoIP rules out the                                 The PSTN is a reasonably tech-savvy, digital system that includes mobile as well
need for any such investment.                                    as fixed telephones. It is governed by various standards defined by the International
    VoIP is also a very reliable tech-                           Telecommunication Union’s telecom standardisation sector (ITU-T).
nology. In a PSTN network, if a line                                However, with the growing popularity of Internet Protocol (IP) based networks,
is down, it is completely cut off and                            especially the Internet, varied methods, tools, protocols and standards have emerged
calls cannot be made from or to tel-                             to enable the transmission of voice and multimedia content over these networks.
                                                                 Essentially, voice over IP or VoIP is a bundle of technologies that enables IP-based
ephones in that line. However, in the
                                                                 networks to be used as communication networks too. While PSTN is circuit-switched,
case of VoIP, multiple routes can be                             VoIP is packet-switched. It sends voice or multimedia as data packets on an IP network.
established to reach a node, and hence
downtime is negligible or nil.
    VoIP is clearly the future of telepho-                handling converged multimedia ap-                     their existing circuit-switched net-
ny as it combines a bouquet of services                   plications, VoIP being one of them.                   works in favour of VoIP.
ranging from video conferencing to                        As long as the legacy voice network
call-forwarding at a very low cost. With                  is somewhat cost-effective and voice                  a mobile dimension
the spread of broadband as well as user                   is the primary application, traditional               to VoIP
awareness, VoIP is slowly picking up at                   circuit-switched voice will continue to               Another recent addition to VoIP tech-
the user level in India, but it is mainly                 dominate,” opines Dr Suresh Borkar,                   nology is mobile VoIP or mVoIP.
the enterprises that have gone gaga                       senior principal investigator, Roberson                   The name is quite self-explanatory.
over VoIP for both long-distance calling                  and Associates, and faculty member, Il-               Mobile VoIP is a term used to describe
as well as internal communications.                       linois Institute of Technology, Chicago.              the delivery of VoIP services via a mo-
                                                               Dr Borkar adds that VoIP is not as               bile handset that is connected to Wi-Fi,
Not a bed of roses                                        competitive as it seems with regard to                WiMAX or 3G cellular networks. The
VoIP seems irresistible, but has still                    feature richness, reliability or quality.             delivery of services will be handled by
not reached traction on a mass scale                      It, of course, potentially utilises the re-           a third-party service provider.
in India, or even in many developed                       sources better since it sends packets as                  Although still nascent, according to
countries for that matter. One of the                     required, instead of reserved resources               a recent Frost & Sullivan report (Impact
primary reasons is that VoIP is based                     as in a circuit-switched voice connec-                of Mobile VoIP on Next Generation Cellu-
on networks that are fundamentally                        tion. But the fundamental premise for                 lar Networks), mobile VoIP is poised to
different from the existing PSTN ones.                    the IP protocol is only its ‘best effort’             become the principal transport for vari-
Since the existing circuit-switched net-                  and so real-time applications like voice              ous access technologies. It might even
works have still not served their life,                   ultimately need to use the seemingly                  end up threatening traditional telecom.
no operator is prepared to sink those                     non-robust protocols like the user da-                    At the end of 2008, approximately
and invest in new IP-based networks.                      tagram protocol/real-time transport                   $605.8 million of mobile VoIP revenues
    Even otherwise, VoIP is still not as                  protocol (UDP/RTP) at higher levels.                  were generated in North America, Eu-
impeccable as it is portrayed to be.                      Plus, circuit infrastructure has also                 rope, Asia Pacific and Latin America.
    “A circuit-switched network is                        consistently been meeting the ‘five                   This, according to the report, is expect-
deterministic. It has set a carrier-grade                 nine’ reliability (.99999) standards,                 ed to grow to $29.57 billion by 2015.
standard, especially in developed                         whereas once again we must remem-                         However, the study points out that
countries, which is hard to match by                      ber that the underlying basis for IP has              many cellular operators have prohib-
VoIP. A packet-switched network                           been only ‘best effort.’                              ited the use of mobile VoIP over their
on the other hand is statistical, but                          So there is really no strong enough              cellular networks, with some imposing
allows tremendous flexibility for                         reason for service providers to ditch                 a surcharge to avoid cannibalisation of

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                                                                                                           sales manager - Unified Communica-
   What VoIP means to businesses?                                                                          tions, Cisco, India & SAARC, points
   How VoIP works for a business is simple: It adds voice to a data network to reduce                      out that according to TRAI guidelines,
   costs, improve productivity, and enhance collaboration. VoIP and IP telephony are                       VoIP can only be provided within
   becoming increasingly popular with large corporations and consumers alike.
                                                                                                           CUGs in the country. Hence such ser-
      For many people, Internet protocol (IP) is not only a way to transport data but also
   a tool that simplifies and streamlines a wide range of business applications, telephony                 vices provided over the PSTN would
   being the most obvious example. VoIP is also the foundation for more advanced unified                   be classified as illegal. As a result,
   communications applications—including Web and video conferencing—that can                               although VoIP has picked up at the
   transform the way organisations do business. The benefits include:                                      enterprise level, it is yet to make its
   1. An organisation saves money by having one network to manage instead of two.                          way into the consumer household, and
   2. Organisations can easily add, move or change phone extensions and locations,                         might not do so in the near future.
        which saves money and gives more flexibility.
                                                                                                               “In a wire-line home environment
   3. Wireless IP phones connect users to the communications system and data
        resources, such as customer information, while they are in the warehouse, on the                   with standard copper connections like
        sales floor or anywhere they can access the organisation’s data network wirelessly.                in India, VoIP can be provided only on
   4. Unified communication solutions for small businesses go beyond basic VoIP                            PCs associated with digital subscriber
        capabilities to enhance collaboration. With a unified communications solution,                     lines (DSL). I believe that number is
        workers can easily collaborate through voice, video chat, Web conference and                       only a few millions. (The total copper
        instant messaging. Employees can collaborate using each technology individually                    connections in India are approximately
        or all of them simultaneously, and from a single, easy-to-use interface.
                                                                                                           35 million and most of them do not
   5. VoIP allows organisations to use features such as voicemail, caller ID, conferencing,
        forwarding and unlimited long-distance calls without having to pay extra for these.                meet the minimum quality require-
   6. Since VoIP is based on the Internet Protocol, it also handles other media types than                 ments for broadband connections.)
        voice such as transferring images, video and text. It is possible to share files or even           Many times, the quality of copper
        communicate with the use of a Web cam.                                                             connections do not meet appropriate
       —By Minhaj Zia, national sales manager-Unified Communications, Cisco, India                         standards and hence DSL cannot even
                                                                                      & SAARC              be provided. Hence VoIP becomes a
                                                                                                           non-starter,” adds Dr Borkar.
                                                                                                               Srinivasan of VIVA Communica-
their circuit-switched voice revenue               munications (DoT) and the Telecom                       tions, which offers DoT-authorised
streams. Moreover, cellular operators              Regulatory Authority of India (TRAI).                   VoIP services, explains that VoIP has
face intense competition from the more             There was a time when it was seen as                    largely been evaded by small- and
popular Web-based VoIP alternatives                completely illegal (it continues to be so               medium-sized businesses (SMBs)
that are permeating the mass market.               in several other countries), but now au-                and has remained restricted to large
     “Mobile VoIP is still in the infancy          thorised service providers are allowed                  enterprises, mainly due to the cost
as the mobile networks that can sup-               to provide VoIP services to the public.                 of IP phones and lack of effective
port end-to-end IP telephony are still             The legality of VoIP remains a big                      penetration of broadband services in
in very early stages of build-out. More-           question in several countries because                   tier II and III cities. Plus, even though
over, the traditional cellular networks            there is no regulatory framework, no                    VoIP is considerably cheaper than the
still have a long life left in them, which         uniformity in services and standards,                   traditional telephone service, it has
will prevent large rollouts of IP-based            and no way to clearly differentiate                     remained attractive only to those seg-
mobile networks,” comments Sharma.                 information services from telecommu-                    ments of the market which spend a lot
     But once it picks up, mVoIP has               nications! All of which makes life very                 on international calls.
the potential to play a crucial role in            difficult for the law-makers.                               The above trends ought to reverse
enhancing the appeal of VoIP not just                  A few years ago, VoIP got its big                   before VoIP becomes more popular in
for large and small enterprises but                break in India when the TRAI gave                       India.
also for individuals, who could use                its approval for the logical partition-
this technology to stay in touch with              ing of PSTN and closed user group                       SIP trunking: 1+1 = 3
their family and friends residing in               (CUG) networks. Standards such as                       The adoption of VoIP in developed
India and abroad. After all, the Indian            the session initiation protocol (SIP) also              countries is increasing now, partly due
population does have a penchant for                emerged to enable integration of legacy                 to technologies like SIP—a trend that
all things mobile!                                 or hybrid systems with newer IP-based                   might extend to India. In those coun-
                                                   ones. As a result, companies could                      tries too, the widespread existence of
VoIP in India                                      merge their voice and data networks                     legacy circuit-switched networks was
VoIP remains subject to several regula-            and reduce their investments therein.                   holding back operators from moving
tions by the Department of Telecom-                    However, Minhaj Zia, national                       to VoIP. But, with advent of SIP, the

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benefits of VoIP could be extended to                     chain, ranging from platform/tool pro-       legacy circuit-switched based approach,
customers over the legacy infrastruc-                     viders like Microsoft, and telcos like       as others are doing around the world.
ture itself. Rather than challenging                      Vonage to device makers like Cisco           “That does open up the possibility for
traditional telecom, VoIP has helped                      have SIP-based solutions.                    ‘over-the-top’ operators like Skype to
to enhance it.                                                 Subject to bandwidth availability,      provide basic VoIP capabilities but they
    Zia says, “To meet the demands of                     a SIP trunk can carry unlimited voice        are not even close to the carrier-grade
the changing business environment,                        calls (though service providers are          circuit-switched voice,” he says.
to attract new customers and to add to                    known to restrict the number of simul-           4G is not likely to change the situa-
their portfolio of revenue-generating                     taneous calls to anywhere between            tion much either. As we migrate to 4G
services, service providers are deploying                 28 and 41 per SIP trunk), versus a           cellular networks like Long-Term Evo-
converged voice-and-data services based                   traditional PSTN/PRI trunk that can          lution (LTE) that have only a packet
on SIP. With its foundation in Internet                   accommodate only 24 calls per channel        core, the capability of providing voice
protocols, SIP provides the ability to                    (realistically, 17.5 calls).                 using the data network through the
integrate traditional voice services with                      According to a recent Frost & Sul-      SIP/IMS platform may not be appli-
Web-based data services, including self-                  livan report on VoIP and SIP trunking,       cable, from the business viewpoint,
based provisioning, instant messaging,                    although businesses of all sizes can ben-    for another three-four years even in
presence and mobility services.”                          efit from the access-line and toll savings   advanced countries. The operators will
    Where legally permitted, SIP has                      offered by VoIP services, SMBs have          hence continue to leverage the circuit
also resulted in the emergence of local                   emerged as an attractive niche for VoIP      core (e.g., of the 3G system) for trans-
exchange carriers and virtual network                     access services. SMBs either deploy IP       mitting voice calls for quite some time
operators who have taken a share of the                   trunking as an overlay service to their      to come. One such example is the Voice
VoIP market by acting as a mediator be-                   existing broadband access (wire line/        over LTE via Generic Access (VoLGA).
tween the PSTN and a company’s LAN                        wireless, DSL, cable, T1/E1, Ethernet,           There is considerable work needed
and providing value-added services.                       etc) or buy pure SIP/H.323 trunks,           before VoIP can meet the carrier-grade
                                                          leveraging the IP trunking provider’s        standards, due to the statistical packet
So what really is SIP                                     network and IP delivery architecture.        nature of the packet network, and will
trunking?                                                      IP trunking using the SIP protocol      have to rely on very complex Qual-
A ‘SIP trunk’ allows a company to re-                     is prevalent in large Indian enterprises.    ity of Service (QoS) treatment along
place traditional fixed PSTN lines with                   If more local exchange carriers crop         with other applications involving
PSTN connectivity via a SIP trunking                      up, and if Indian SMBs also go for it,       data and video, explains Dr Borkar,
service provider on the Internet. SIP                     SIP could well be a factor that could        while agreeing that ultimately all
is a lightweight module used for the                      contribute to the growth of VoIP in          multimedia services, including voice
setup of a session between two or more                    India too.                                   for wireline and cellular mobile units,
parties. It works on the application                                                                   will be provided on the packet trans-
layer, using a text-based interface, and                  The future of VoIP in India                  port with all the feature-richness. But
is hence easy-to-use and flexible.                        As the new broadband networks are            that eventuality is a long way off, at
    To use a SIP-based service, a com-                    built out, we could see VoIP becoming        least five years, for reasonable market
pany would need an IP-based private                       more prevalent in the Indian market.         penetration.
business exchange (PBX) or a tradi-                           With the recent Broadband Wire-              There is no reason to immediately
tional digital or analogue PBX with a                     less Access (BWA) auction, we an-            phase out the traditional networks
SIP trunking interface. It also needs an                  ticipate large rollouts of WiMAX net-        as it took a lot of investment to build
edge device that supports SIP, which                      works in the country in the near future.     them and they are doing well for voice
can act as an interface between the                       “WiMAX networks are based on all-IP          communications. However, since the
local-area network and the Internet tel-                  technology and will certainly run very       advantages of VoIP are quite compel-
ephone service provider (ITSP), who,                      economical VoIP. Mobile VoIP will            ling, new VoIP networks could be built
in turn, connects to the PSTN.                            take a long time to be introduced in         in areas where traditional telephony
    In short, SIP trunking enables a                      the country as today’s mobile networks       is lacking and also where there are
service provider to use the PSTN as the                   are largely built using circuit-switched     serious capacity constraints. Further,
base to provide IP-based services at the                  technology, and it will take a long          SIP trunking could be used to extend
application layer. It enables enterprises                 time to convert them to end-to-end IP        legacy infrastructure to benefit from
to tap the benefits of VoIP without                       networks,” says Sharma.                      VoIP. 
washing out their legacy communica-                           Dr Borkar feels that even after 3G
tion systems.                                             wireless becomes available in India, ser-    The author is a technically-qualified freelance writer,
    Players across the telecom value                      vice providers will continue to use the      editor and hands-on mom based in Bengaluru

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