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Having It All:
An Audio Conferencing Strategy for Networks in Transition
WHITE PAPER Having It All: An Audio Conferencing Strategy for Networks in Transition
WHITE PAPER Having It All: An Audio Conferencing Strategy for Networks in Transition
Overview
But it was unavoidable that this continued pressure to stretch
the built-in constraints of POTS and PSTN would lead to the
development of wholly new kinds of endpoints and ways to
connect and network them, and that is the situation facing any
IT manager or audio conferencing buyer today. We’re now
positioned at a time where there are numerous attractive new
options for phone connection, while many of the old systems
are still in place and working. Hosted and unhosted alternatives
are proliferating, and customers are looking for ways to ensure
that changing a network or a service vendor next year won’t
mean scrapping all those equipment investments as well.
Alternatives in the universal network
Cellular network
But POTS is far from alone these days. With the rapid growth
of wired and wireless technology, we are seeing an increasing
range of options to move beyond the POTS connection.
Taken all together, they form a kind of “universal” network in
which there is some element, somewhere, that can support
almost any capability imaginable. This is often a good thing,
but each of these options also has its own distinctive strengths
and weaknesses. This profusion of choices can make a
selection difficult.
• We sacrifice a lot for that independence. The unreliability of
a cell phone connection, for one thing, is so ubiquitous as to
have lost its novelty even as a topic for comedy.
This paper will review these different alternatives, look at their
advantages and drawbacks, and offer some suggestions as
to how an organization can position itself for the future while
continuing to make the most of its existing investments, and
how that organization can continue to benefit from the stability
of what is working today.
The newest part of the “universal network” comes from the
use of IP (Internet protocol, or just “Internet”) for telephony.
Because IP carries data regardless of its meaning, that
data can represent anything, from voice to video, graphics,
entertainment, messaging, status information, data files…but
why am I telling you what data is? When it’s used for voice, VoIP
(Voice over IP) telephony offers a different set of advantages
and disadvantages.
A revolution is occurring in company telephone networks
today. They are moving from older POTS and proprietary digital
plans to IP, and this can make it hard to decide how to make
the ongoing investments that keep them running. In this paper,
we consider the different alternatives, and how the inclusion of
multiple network abilities in an audio conferencing device can
assure both excellent performance and investment protection.
Introduction
For decades now, telephony has been slowly awakening from
Alexander Graham Bell’s analog dream of a wired narrowband
audio service, to a host of agile communications abilities. But
any change that affects billions of devices is a big change, and
big changes never happen all at once. The evolution of voice
and video communications is not happening at one time or in
one place, so the solutions we select need to work across an
unprecedented breadth of networks and environments.
“Phone connection” has had twin meanings for a long time,
but we are now comfortable with the distinction between how
a phone is connected to the wall, and how a conversation is
carried around the world. When we talk about the PSTN, or
Public Switched Telephone Network, we’re referring to the
massive and mature worldwide structure that lets us connect
any one telephone to another. POTS, on the other hand, as
Plain Old Telephone Service, is more often used to refer to the
analog subscriber loop or twisted-pair hardware connection:
that single pair of wires on which two-way audio is melded with
dialing, presence, hook status, other signaling, and DC power
to form a specific hardware interface to an endpoint.
Connecting POTS telephones to one another through the
PSTN network has long been one of the simplest and most
common configurations, but the 20th century saw rapid growth
in the varieties and capabilities of phone systems. Analog,
and later digital, proprietary PBXs routinely discarded the
old POTS interface for a direct customized phone interface,
allowing them to add new features and manage costs while still
connecting through the PSTN for longer-distance connections.
As time went by, POTS and the PSTN were able to provide
new abilities such as facsimile (initially analog, later digital), and
even the direct transmission of computer data (in which, once
the theoretical limit of 3200 bps was reached, we developed
new theories and boosted this to 56000 bps over the very
same networks, and then to 4 Mbps and higher by more finely
parsing the meaning of “network”).
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PSTN: Still here for a reason
Millions of telephone connections are still secured by twistedpair POTS interfaces. Many enterprises have plans for VoIP and
UC conversion, but even enterprises that have enthusiastically
changed over their entire telephony backbone still hold on to a
competent number of POTS connections. There are some very
good reasons for this.
POTS remains the unchallenged champion when it comes
to reliability in communications. When someone says “five
nines,” we don’t think of a free Internet phone service, we think
PSTN. Carriers have spent a century buttressing this powerful,
multiply-redundant network, and it has become legendary for
its invariant ability to connect its network-powered endpoints
under almost all circumstances.
The PSTN is highly tolerant of abuse and misuse (a
characteristic which is one advantage of setting low
expectations and then exceeding them brilliantly). Some of the
first phone systems were private networks, running from farm
to farm over wire fences, and this kind of broad-mindedness in
defining an architecture can be a real benefit when dealing with
widespread geographies and changing environments.
And, of course, the PSTN is here already. Costs are already
sunk, the troubleshooting has been troubleshot, and analog
telephony is in place and working worldwide. Complex issues
of interworking among networks worldwide have been
long solved, yielding a system that works reliably among
endpoints everywhere.
VoIP and open SIP
• Since VoIP is carried over the IP network, no separate
network is required as there is with POTS or wireless
• Because the nature of the data is transparent to the network,
no inherent restriction exists on the abilities that can be
implemented
• Digital communication lets noise be quantified rather than
encountered haphazardly. On any reliable network, noise
and distortion is carefully apportioned, most often as part of
a tradeoff between data bandwidth and sound quality
• The emergence of high-efficiency, high fidelity open standard
audio codecs has enabled extremely high-quality audio and
video on conventional data networks at low cost.
• Anywhere IP goes, VoIP can travel. Since IP is carried over
a wealth of wired and wireless media, VoIP has enormous
reach, often extending to places where even cellular phones
cannot connect.
• Among the challenges is the fact that many VoIP networks
are still fairly isolated. Even today, a VoIP phone on one
network often cannot dial directly to a VoIP phone on
another without both networks passing their traffic through—
you guessed it—the narrowband PSTN.
• Another VoIP issue is that phones must be properly registered
and configured or they don’t work. While a POTS phone will
plug in and get a dial tone if the jack is live, carrying a VoIP
phone to another facility or even another subnet within the
same building can be an uncertain proposition.
• One other thing about VoIP is this: for organizations of all
sizes, the transition to VoIP takes time, and new systems
overlap the old. It’s not uncommon to find buildings in which
some rooms have extensive VoIP connectivity while others
have simple POTS connections and (non-VoIP) Internet jacks.
• The cellular phone has transformed our conception of being
“connected” by letting us stay in touch from vastly more
places than is possible from wired (or wireless VoIP) phones.
• Sound quality on cellular phones is another accepted
compromise. Cell phones have traditionally sounded muffled,
squawky and a fine conduit for any airport public-service
announcement that drifts by.
It’s interesting how, with its limitations and drawbacks that
directly contradict any philosophy of “five nines,” the cellular
phone is still almost universally welcomed. When cell phones
work, they add a vital link to locations and settings that can be
untouchable otherwise, and that versatility has enormous value
in almost any application.
Proprietary VoIP
A constantly-shifting range of specialized proprietary and
open-source systems are available for telephony over IP
today; a quick look at Wikipedia reveals more than 40 distinct
VoIP systems available for use (look under “comparison_of_
VoIP_software”).
These systems vary widely in capabilities, licenses, scope,
encryption, compatibility, performance, and so forth. There are
many explanations for these differences, but one consequence
is a continuing explosion in incompatibility, even among
VoIP systems.
Workplaces
It used to be that the telephone’s place was on the office
desk, the speakerphone’s on the conference table. This
is still sometimes true, but there’s been a proliferation in
workplace types that is throwing phones into a host of new
and often challenging environments. This shift in work styles
is happening for a number of reasons: new perspectives have
emerged on how work can be done in facilities; definitions of
facilities themselves have become less “traditional,” and the
number of remote workers and remote workgroups is growing
enormously. Consequently, a business audio teleconference
may have participants from almost anywhere: a group of
people sitting together in a big, loosely sketched cubicle
area; a couple of workers in home offices; a surgical team in
an operating room; or an open space in the stockroom of an
offshore oil drilling platform, just to suggest a few.
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WHITE PAPER Having It All: An Audio Conferencing Strategy for Networks in Transition
WHITE PAPER Having It All: An Audio Conferencing Strategy for Networks in Transition
Physical hosts
Dependable performance
At the same time as conference places are changing, what is
used as conference devices is expanding, as well. Today, cell
phones and laptop computers are often pressed into service as
speakerphones, while earbuds make “hands free” possible with
no loudspeaker at all. But these stand-ins often don’t work as
well as we think. We all know from long experience that those
on the other side of a phone conversation will gallantly tolerate
even the worst corruption and noise without commenting
unless they absolutely cannot hear what’s being said. Rather
than asking “can you repeat that,” listeners commonly let it go,
gradually falling out of the discussion completely.
Telephone priorities on the universal network
Change in how we communicate today is the rule, not the
exception, and businesses must continue adapting and
investing in spite of all these shifting winds.
Given the speed with which networks are being created and
evolved, and the expanding ways in and places from which
people are doing business, it’s worth taking a new look at what
priorities apply when choosing an audio conferencing system.
How important are the characteristics we valued yesterday?
And what is essential today that was unheard of yesterday?
As it turns out, there are two broad priorities that come out on
top: versatility and reliability.
Versatility
Where it’s used
It’s hard to predict precisely where a particular system will be
installed. This means that an audio conference system has to
adapt to a wide range of acoustic environments: a key participant
in an important meeting can call from anywhere--from a full-sized
conference room to a small office, a cubicle, and even an open
area in the middle of a building. Ventilation grilles, computer
fans, tapping keyboards, bad room acoustics, and people sitting
everywhere from up close to the back of the room and even nonparticipating passersby are all part of the challenge that an audio
conference system must handle flawlessly.
Multi-network connectivity
As organizations shift among different service vendors and
network formats, the most important response by audio
conferencing systems must be that they keep working. A
system may have been planned as part of a SIP network but
then be unexpectedly needed in a session over AOL, Blink, or
ZPhone. A planned Skype video call may run afoul of a firewall
and the only option to have the meeting is to use that POTS
jack nearby or to cluster around the one working cell phone
in the room. Further, there’s no guarantee that the service in
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place today is what IT will find optimal tomorrow. It wasn’t that
long ago that it would have been unimaginable to question
whether a phone could plug into the phone network, but today
the question is not whether there are a half-dozen active
networks, the question is which network shall we use for this
particular meeting?
Equipment pools
Most organizations don’t want to pay for a permanent
conference phone at every single wall jack. One common
solution is to maintain one or more centralized pools,
dispatching devices like audio conferencing systems at need
and then re-collecting them after meetings are completed.
This approach puts a higher emphasis on the need for a sturdy,
reliable solution for several reasons:
• Uncertain wall jack. There’s only one chance for the
“speakerphone from the A/V pool” to work wherever it’s
delivered. Because networks are always in flux, the chances
of a working connection are much higher when more
than one kind of connection is supported by the traveling
system. Incorporating multiple network interfaces in audio
conferencing systems to be dispatched ad hoc makes a
business more robust, regardless of the preferred network.
• Sturdiness. Some conference systems are moved two or
three times a day: unplugged, dropped on a cart, wheeled to
another floor or another building, and thrown onto a table or
a counter in front of an unforgiving audience. Equipment isn’t
coddled like fine china, and it has to be built to meet this kind
of casual treatment.
• Power. The destination may have an AC power jack
somewhere, but that doesn’t mean there’s one nearby
or available. A unit that can accommodate both power
over Ethernet (PoE) as well as AC power means that the
destination doesn’t need to be near both an AC jack as well
as an Internet jack.
Future proofing
A lot of organizations are still in a transitional state when it
comes to their telco networks. “I know what I want us to do,
but we haven’t done it yet” is a common remark we hear.
Networks may be partly VoIP and partly POTS; some may even
still be proprietary digital throughout, using terminal adapters
for devices like fax machines and conferencing systems.
Trapped in this in-between state, their managers are reluctant
to purchase new POTS equipment because they know they’re
moving toward VoIP although they may not know exactly when.
These managers are torn between conflicting requirements.
A new conferencing system has to hook up and work in the
network as it exists today, yet continue to work as well, or
better, whenever the new network arrives.
When a conferencing system can connect to a variety of
networks, one challenge is that each network usually has
different strengths and shortcomings, as mentioned above.
Conventional PSTN telephony, for example, doesn’t support
HD Voice, while the VoIP networks which do sometimes
suffer from degraded reliability due to connection problems,
dropped packets, and other causes. “Jack of all trades but
master of none” isn’t acceptable behavior for a piece of core
communication technology; it has to be a top performer on
every interface, understand the strengths and weakness of
each, and configure itself accordingly.
Failover
When a telephony network goes down before or during a
conference call, a common response is confusion: people
suddenly find themselves trying to be their own IT specialists,
figuring out what happened, where it happened (Is it working
at this end? Did the other end hang up? Is the network down?),
what to do about it (Is there another room? Do we have a
speakerphone that can plug into this other jack?), and taking
action (Does anybody have Pamela’s landline number?). The
preferred behavior is one in which an endpoint can implement
its own “Plan B,” by taking advantage of the fact that most
locations have more than one separate network available,
especially in conference rooms. Automatically switching to
a PSTN connection on loss of VoIP (or vice versa), and back
again on recovery, is a quick and easy way to re-establish a call
across a backup network and keep the conversation going.
Transparent speech
Supporting HD voice as well as narrowband, implementing
multiple codecs and open standards, and building-in
inherent resistance to network problems and poor acoustic
environments are basic requirements of an audio conferencing
system. These help assure that whatever new capabilities
come with a system upgrade, the conference unit will be ready
to take advantage of them.
Simple operation and configuration
A number of past-generation telephony systems became
infamous for their complexity of configuration and difficulty of
use. Nobody expects to need an instruction manual to place
a phone call, so an endpoint, especially one shared among
assorted users, has to be elegant and forgiving in its operation.
Open standards
An important aspect of reliable operation is the ability
for everyone to be able to access the same methods of
communication. This applies to everything from the use of
openly available protocols and standards such as PSTN, SIP,
LDAP and a host of others; G.711, G.722, and multiple other
common audio codecs; and to a the use of simple and common
user interfaces.
Connection independence
A system needs to adapt to a wide range of requirements when
connecting via multiple networks. VoIP approaches DTMF
signaling differently than POTS, for example, and caller ID and
directory services work differently in different countries and
over different networks. Working well over multiple networks
doesn’t stop at the dial tone; all essential functions have to be
tuned to meet the requirements of each network.
Single system, multiple networks: The
Polycom® SoundStation® Duo
The Polycom® SoundStation® Duo solution is the first in a class
of audio conferencing systems that is designed to deliver the
best from multiple network connections: VoIP, PSTN, audio, and
cell phone. The philosophy behind the creation of the Duo is
unique, and embodies the two major principles detailed above:
versatility and dependable performance.
• A s a VoIP conferencing system using SIP, the SoundStation
Duo phone supports superb speech clarity with Polycom
HD Voice™ technology, and defends against erratic data
networks with packet loss concealment, adaptive jitter
buffers, and low-delay packet transmission
• When connected using its POTS interface, the SoundStation
Duo solution is a robust, reliable conferencing system that
supports multiple caller ID protocols and is compatible with
specialized network requirements, ringer responses, and line
impedances worldwide.
• Connected to a network through a user’s cell phone, the
SoundStation Duo phone brings full-duplex, whole-room
coverage to whatever cellular network the user chooses.
By leveraging the user’s own wireless connection, the
SoundStation Duo phone is instantly localized, and adds a
professional full-duplex room conferencing capability to any
cellular network regardless of region or country.
• And by connecting the SoundStation Duo phone using a host
computer’s audio interface, virtually any specialized or custom
protocol can be supported, from common systems like
Google Voice and Skype to the arcane and highly specialized
protocols used in some demanding environments.
Most locations still have PSTN connections available and this is
especially true in conference rooms. Because the SoundStation
Duo phone can automatically failover to a PSTN connection
on loss of VoIP (and back again on recovery), it is quick and
easy to re-establish a call across a backup network and keep a
conversation going.
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WHITE PAPER Having It All: An Audio Conferencing Strategy for Networks in Transition
Conclusion
Change happens in stages more often than it happens all at
once. Plans get delayed or what is sometimes worse, they
unexpectedly fall into place without warning. So while it’s
possible to be fully prepared for network changes, and it’s
easy to hold off spending on new capabilities until just when
they’re needed, it’s hard to do both. That’s why the Polycom
SoundStation Duo solution is such a compelling proposition.
The SoundStation Duo phone makes Polycom group audio
available to all networks, so it provides extraordinary leverage
of an organization’s communications investment. By building
around a transparent Polycom HD Voice audio conferencing
core, and supporting it with a clear multilingual graphic UI,
simple configuration, and easy support, the SoundStation Duo
architecture brings these critical communication elements
to any communications network. When a network changes,
users aren’t confronted with a whole new system and this
yields another savings in time and convenience.
One of the most critical needs we ask of an audio conference
system is the simplest: it should stay out of the way, and let
users get on with business. The SoundStation Duo solution
delivers this experience by connecting transparent interactive
conversation from whatever room or space is being used,
over whatever network is most convenient. A versatile and
top-performing solution, integrated with a robust Plan B, is a
pretty good match to most network requirements.
About the author
Jeffrey Rodman, Co-Founder, Fellow, Polycom, Inc.
Jeff Rodman is focused on ensuring the best and most
transparent human communication experiences over local
and remote connections. Prior to Polycom, he led definition
and development of innovative new media products in
roles including PictureTel‘s first engineering director and
digital video products for the Broadcast division of Harris.
Jeff holds an MS and a BSEE cum laude from CSUN, and
has written numerous articles, songs, and one musical. He
frequently speaks on topics of communications and media,
being consulted when the topic turns to telepresence and HD
voice technology.
About Polycom
Polycom helps organizations unleash the power of human collaboration. More than 400,000 companies and institutions
worldwide defy distance with video, voice and content solutions from Polycom. Polycom and its global partner ecosystem provide
flexible collaboration solutions for any environment that deliver the best user experience and unmatched investment protection.
Polycom, Inc.
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