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Voice over Internet Protocol (VoIP) has been growing steadily in popularity over the past
years. Instant messenger clients with voice chat features have given way to P2P (peer-to-
peer) VoIP clients like Skype. We take a closer look at VoIP (Voice over Internet Protocol)
technology, and the challenges and innovations associated with it.
C M Y K
VoIP, or Voice over Internet
Protocol, is the technology used totransmit voice over the Internet. Also
known as ‘Internet telephony’, itinvolves breaking up analogue voice
data into digital packets, and thentransmitting these packets using the
Peering Under The HoodOf VoIP Technology
if you have been on the Internet
long enough, there is a goodchance that you have spoken
to someone over the Internet,either using a traditional chat
client (like Yahoo!), or P2P softwarelike Skype.
P.A. MonteiroThe author is a freelance writer living in Bangalore.
He advocates the user’s point of view on his blog athttp://allaboutusers.wordpress.com
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and data provides opportunities for
companies to innovate solutions. Forexample, one company allows you to
receive your voice messages as MP3files that are sent as attachments to your
e-mail address. We also look at some
other innovations in the VoIP space.Click to call: You may havealready seen websites that allow you to
click on a button and chat with ‘live’support personnel. Similarly, a VoIP
technology called click-to-call allowsyou to call people by clicking a banner
or a button on a website. Click-to-callis already being offered by companies
like Ifbyphone, Yellow Pages andEsqube Communication Solutions.
VQube, India’s own P2P VoIP tool: Esqube Communication
Solutions Pvt Ltd, a Bangalore-basedcompany, recently released a product
called VQube, which the company calls, “…a peer to peer Voice over IP
interactive communication tool that
offers voice, video, text chat and voicemail.”
On the subject of how the Esqubeteam designed the product to address
technical challenges in the Indianmarket, Dr K V S Hari, CEO,
Esqube Communication Solutions
Pvt Ltd, says, “e main technicalchallenges we face in India are inthe areas of hardware limitations,
network constraints, and bandwidthlimitations.”
He reveals, “VQube uses alightweight voice codec that needs
lower CPU time (compared to othercodecs), thus keeping the CPU and
memory requirements to a minimum.is means that VQube works
satisfactorily on older machines and on
older versions of operating systems, as well as on set-top boxes installed withLinux and Windows mobile phones.”
“Since bandwidth in India is stillat a premium, VQube uses a secure,
lightweight protocol for transportingvoice packets, which reduces the
overhead and contributes to bandwidth
reduction. Bandwidth usage (for voice
and video calls) was also minimisedusing techniques like dynamic voice-
codec switching, video frame rateselection, and so on,” he says.
About the network-related
challenges, Dr Hari says, “In many networks, the desktop is in a privateIP behind a NAT (network address
translation), with the same Internetconnection shared by all users.
Sometimes the Internet connection isin a tight firewall (only standard ports
are open to the outside world), and canonly be accessed via a proxy.”
“VQube’s network discovery protocol detects the type of network,
the type of proxy, and the portsthat are open for voice packets to go
through, and automatically routesthe packet without reconfiguring the
network. Also, in most conditions,packets travel P2P, thus minimising the
delay,” he adds.
IP video: If you can transmit voice
and data using IP, then the next step would be to add video. Companies are
already working on products like IPvideo phones, and video conferencing
systems.
About IP video phones, Kumarsays, “Ittiam’s technology has beenlicensed and taken to market by
multiple vendors, and is currently under a trial run by an Asian major.
Although the IP video phone is stillan emerging market, there is a clear
sign of increasing interest and intent of
adoption by major OEMs around the
world.e future of video telephony is
bright, and it will come into our livesin multiple forms, like video phones on
desktops, video phones on IPSTBs (IP
Set Top Boxes), video communicationembedded in ATMs, etc.”
Private networks : Since the
Internet is a public network, there areinherent pitfalls (e.g., security, voice
vs data traffi c priority) associated with transmitting voice calls over the
Internet. Some VoIP service providersuse dedicated private networks that
enable secure and faster transmissionof voice calls. Using private networks
also allows service providers to tweak parameters for better performance (for
example, prioritise voice traffi c overdata traffi c).
One example of a private network is the Multi-protocol Label Switching
(MPLS) network that is used by VoIP
service providers.
Challenges facing VoIP
Since VoIP is a relatively new technology, challenges are to be
expected as the technology matures.
We look at some of the challenges inthis domain.
Security: e one challenge thatseems to come up in every discussion of
VoIP, is security. Addressing this point,Minhaj Zia, business development
manager, Cisco India & SAARC says,“One of the most common threats is a
denial of service (DoS) attack, whichshuts down applications or servers.
ese attacks are often made againstrouters or Web servers, but they can
also be used to target call-processingservers in IP telephony networks.
“Call tampering, which involvestampering with a phone call in
progress, is also emerging as a threat.For example, the attacker can spoil
the quality of the call by injectingnoise packets in the communication
The convergenceof voice anddata providesopportunitiesfor companies
to innovatesolutions.
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t e c h f o c u s stream. Or the attacker could withhold
the delivery of packets, so that thecommunication becomes spotty and
the participants encounter long periodsof silence during a call.”
Shawn Conroy, vice president -
voice networking, AT&T Inc says, “A secure VoIP deployment must includea combination of existing IP security
mechanisms and VoIP-specific security mechanisms. Ultimately, the security
of a customer’s VoIP services dependsnot only on the security measures that
the vendor deploys in its network andservices, but also on the security that
the enterprise customer implements atits own locations.”
He adds, “Many of the security measures taken by vendors such as
AT&T, to secure VoIP, must also bedeployed by an enterprise on its own
devices to be fully effective. Security at the customer’s premises is a critical
component of end-to-end VoIP
security.”Prof Schulzrinne expresses his views
on security saying, “In my opinion,
most of the problems can be traced
back to implementations —eithersloppy implementations that fall prey
to buffer overflow and call-state attacks,or lazy implementers who do not
implement well-documented security
techniques, such as TLS (TransportLayer Security) for signalling. eone major protocol deficiency is
probably the lack of a standardised key agreement protocol for media security.”
Spam calls : Because VoIP callsare sometimes routed through public
networks (like the Internet), there is apossibility of spam. Prof Schulzrinne
says, “I have not heard about any real incidents of SIP-based spam,
presumably because most SIP-basedsystems are still closed. SIP Identity is
a precondition for many of the otherspam-fighting techniques, such as white
and blacklists, or more sophisticatedversions, such as whitelists based on
social networks.”
He adds, “Several other kindsof techniques have been proposed,
such as detecting spam calls based onfrequency or duration, or using the fact
that callers start speaking immediately rather than waiting for a “Hello”
greeting. Most of the techniques in the
latter group have the disadvantage that
they are likely to suffer from high false-positive rates, i.e., non-spam calls that
are falsely labelled as spam. (For example,automated phone alerts or airline
departure delay notifications are likely to
be labelled spam.)”Codecs: About the challenges inimplementing codecs for VoIP-related
technologies, Kumar says, “For VoIP-related technologies, several aspects
of codecs and components need to beexamined. e most important ones are
implementation optimisation, system-friendly implementation and testing.
Since VoIP is a low-delay real-time system, the algorithms should be
optimally implemented so that they introduce the least amount of processing
delay. In addition to implementationoptimisation, the components must be
usable, and implemented so that thesystem has maximum flexibility in using
them.”
He adds, “A core component likea codec must then be put through
stringent and exhaustive tests. Examplesof such tests are, a speech decoder’s
behaviour if the data is corrupted, or anecho canceller’s performance when put
through a non-linear path.”
Issues specific to India : On thechallenges faced by VoIP in India,Zia opines, “In India, the biggest
challenges were the regulatory restrictionsimposed by the Indian government
and interoperability issues that resultedfrom a lack of standardisation. Until
recently, a single infrastructure for publicswitched telephone network (PSTN)
and Closed User Group (CUG) was notallowed in India. However, the TRAI’s
(Telecom Regulatory Authority of
India) notification on the approval for“logical partitioning” of PSTN and CUGnetworks means that companies can
reduce their investment expenses. is isbecause they would not have to manage
the expense of two separate (PSTN andCUG) networks.”
About the non-technical challenges
Experts believe that a secure VoIP deployment
must include a combination of existing IP security
mechanisms and VoIP-specific security mechanisms
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faced in India, Rajasekharan N K,
executive vice-president—BusinessDevelopment, Esqube says, “One
challenge is the reluctance of IndianISPs to adopt Esqube’s home-
grown technology in spite of the
threat of revenue loss from (foreign)service providers like Skype. eother challenge is the government’s
regulatory framework related to therestriction of VoIP to PSTN gateway
termination within India.”
The future of VoIP We asked people from the industry
about the future of VoIP in India.
Shawn Conroy observes: “BusinessVoIP is picking up speed as more
companies are turning to VoIP toimprove functionality and increase
cost effi ciencies. ere is a sizablegrowth market, particularly in India,
as corporations are leveraging VoIPsolutions and services.”
Rajasekharan shares a similar
opinion: “e future of VoIP in Indialooks positive. Products like VQube,
which support secure multimediacommunication, in addition to
VoIP, will find traction due to multi-
location enterprises that are lookingat improving effi ciency and reducingcost. Students travelling abroad
for higher education will drive theresidential VoIP markets, since families
and friends will want to keep in
touch at low costs. In addition, socialnetworking sites like marriage portals
will find a need to adopt VoIP to
attract more memberships.”
K L Narayanan, head—BusinessUnit, Convergence, Avaya
GlobalConnect adds, “Clearly, thefuture of communications is VoIP.
Businesses and consumers are already
taking advantage of the cost savingsand new features of making calls over aconverged voice-data network.
“e logical next step is to takethose advantages to the wireless world.
e potential impact of wireless VoIPon the communications market is
enormous.“Wireless VoIP offers potential
savings by allowing companies tochange the way they manage their
phone systems. On the lines of Web2.0, there could be something like VoIP
2.0, which will facilitate more flexibility,customisation and powerful features. It
will be the next phase of VoIP.”e future is clearly bright for
VoIP.
“Clearly,the future of
communicationsis VoIP.”
K.L. Narayanan, head—Business Unit, Convergence,Avaya GlobalConnect
PowerPoint Gets Unpopular in the US Military?
Believe IT or NotNimish Dubeynimishdubey@gmail.com
m icrosoft’s PowerPoint
might be themost powerful
presentation toolin the world,
but it seems to have run afoul of theUS military. In his best-selling work
on the ongoing war in Iraq, ‘Fiasco’, journalist omas E Ricks points out
that many members of the US military
were extremely irritated with someoffi cers’ penchant for using PowerPoint
presentations to get their point across.Ricks quotes Lieutenant General
David McKiernan as saying: “In lieu of an order, or a frag (fragmentary) order, or
plan, you get a set of PowerPoint slides...at is frustrating because nobody wants
annoyance with PowerPoint became
evident when the person in commandof the third ACR in Iraq, Colonel H
R McMaster, decided to challengethe current military culture – in
Ricks’ words: “…all but banning theuse of PowerPoint briefings by his
offi cers. e army loves these bulletedbriefings, but McMaster had come to
believe that the ubiquitous software
inhibits clarity in thinking, expressionand planning.”
Well, it seems that Microsoft willneed to beef up its sales pitch to the
US military in the coming days, if Ricks’ claims are true. Or maybe just
train the offi cers to use PowerPointmore effectively.
to plan against PowerPoint slides.”Retired Colonel Andrew Bacevich
is quoted as being equally scathingin his criticism: “Here may be the
clearest manifestation of ... theassumption among forward thinkers
that technology—above all, informationtechnology—has rendered obsolete the
conventions traditionally governingthe conduct of war. To imagine that
PowerPoint slides can substitute forsuch means is really the height of
recklessness.”e extent of the military’s