11.4. The Future of
Asterisk
We've come to love the Internet, both because it
is so rich in content and inexpensive and, perhaps more
importantly, because it allows us to define how we communicate. As
its ability to carry richer forms of media advances, we'll find
ourselves using it more and more. Once Internet voice delivers
quality that rivals (or betters) the capabilities of the PSTN, the
phone company had better look for another line of business. The
PSTN will cease to exist and become little more than one more
communications protocol the Internet happily carries for us. As
with most of the rest of the Internet, open source technologies
will lead this transformation.
11.4.1. Speech Processing
The dream of having our technical inventions
talk to us is older than the telephone itself. Each new advance in
technology spurs a new wave of eager experimentation. Generally,
results never quite meet expectations, possibly because as soon as
a machine says something that sounds intelligent, most people assume that it
is intelligent.
People who program and maintain computers
realize their limitations, and thus tend to allow for their
weaknesses. Everybody else just expects their computers and
software to work. The amount of thinking a user must do to interact
with a computer is often inversely proportional to the amount of
thinking the design team did. Simple interfaces belie complex
design decisions.
The challenge, therefore, is to design a system
that has anticipated the most common desires of its users, and can
also adroitly handle unexpected challenges.
11.4.1.1. Festival
The Festival text-to-speech server can transform
text into spoken words. While this is a whole lot of fun to play
with, there are many challenges to overcome.
For Asterisk, an obvious value of text to speech
might be the ability to have your telephone system read your emails
back to you. Of course, if you've noticed the somewhat poor
grammar, punctuation, and spelling typically found in email
messages these days, you can perhaps appreciate the challenges this
poses.
One cannot help but wonder if the emergence of
text to speech will inspire a new generation of people dedicated to
proper writing. Seeing spelling and punctuation errors on the
screen is frustrating enoughhaving to hear a computer speak such
things will require a level of Zazen that few possess.
11.4.1.2. Sphinx
If text to speech is rocket science, speech
recognition is science fiction.
Speech recognition can actually work very well,
but unfortunately this is generally true only if you provide it
with the right conditionsand the right conditions are not those
found on a telephone network. Even a perfect PSTN connection is
considered to be at the lowest acceptable limit for accurate speech
recognition. Add in compressed and lossy VoIP connections, or a
cell phone, and you will discover far more limitations than
uses.
Asterisk has the potential to be a fantastic
system for speech recognition, due to its flexibility.
Unfortunately, speech recognition itself is not yet mature enough
to be put to the kinds of uses we want of it. As this technology
ripens, the open source community is the most likely to embrace it
and provide flexible, powerful platforms on which to run it.
11.4.2. High-Fidelity Voice
As we gain access to more and more bandwidth, it
becomes less and less easy to understand why we still use
low-fidelity codecs. Many people do not realize that Skype uses a
higher fidelity than a telephone; it's a large part of the reason
why Skype has a reputation for sounding so good.
If you were ever to phone CNN, wouldn't you love
to hear James Earl Jones's mellifluous voice saying "This is CNN,"
instead of some tinny electronic recording? And if you think
Allison Smith sounds good through the
phone, you should hear her in person!
In the future, we will expect, and get,
high-fidelity voice though our
communications equipment.
11.4.3. Video
Video is in some ways already compatible with
Asterisk. The problem is not so much one of functionality as one of
bandwidth and processing power. More significantly, it is not yet
important enough to the community to merit the attention it
needs.
11.4.3.1. The challenge of
video-conferencing
The concept of video-conferencing has been around since the invention of the
cathode ray tube. The telecom industry has been promising a
video-conferencing device in every home for decades.
As with so many other communications
technologies, if you have video-conferencing in your house, you are
probably running it over the Internet, with a simple, inexpensive
webcam. Still, it seems that people see video-conferencing as a bit
gimmicky. Yes, you can see the person you're talking to, but
there's something missing.
11.4.3.2. Why we love
video-conferencing
Video-conferencing promises a richer
communications experience than the telephone. Rather than hearing a
disembodied voice, the nuances of speech that come from eye-to-eye
communication are possible.
11.4.3.3. Why video-conferencing may
never totally replace voice
There are some challenges to overcome, though,
and not all of them are technical.
Consider this: using a plain telephone, people
working from their home offices can have business conversations,
un-showered, in their underwear, feet on the desk, coffee in handif
they use a telephone. A similar video conversation would require
half an hour of grooming to prepare for, and couldn't happen in the
kitchen, on the patio, or... well, you get the idea.
Also, the promise of eye-to-eye communication
over video will never happen as long as the focal points of the
participants are not in line with the cameras. If you look at the
camera, your audience will see you looking at them, but you won't
see them. If you look at your screen to see whom you are talking
to, the camera will show you looking down at somethingnot at your
audience. That looks impersonal. Perhaps if a videophone could be
designed like a Tele-Prompt-R, where the camera was behind the
screen, it wouldn't feel so unnatural. As it stands, there's
something psychological that's missing. Video ends up being a
gimmick.
11.4.4. Wireless
Since Asterisk is fully VoIP-enabled,
wireless is all part of the
package.
11.4.4.1. Wi-Fi
Wi-Fi is going to
be the office mobility solution for VoIP phones. This technology is
already quite mature. The biggest hurdle is the cost of handsets,
which can be expected to improve as competitive pressure from
around the world drives down prices.
11.4.4.2. Wi-MAX
Since we are so bravely predicting so many
things, it's not hard to predict that Wi-MAX spells the beginning
of the end for traditional cellular telephone networks.
With wireless Internet access within the reach
of most communities, what value will there be in expensive cellular
service?
11.4.5. Unified Messaging
This is a term that has been hyped by the
telecom industry for years, but adoption has been far slower than
predicted.
Unified Messaging is the concept of tying voice
and text-messaging systems into one. With Asterisk, the two don't
need to be artificially combined, as Asterisk already treats them
the same way.
Just by examining the terms, unified and messaging, we can see that the integration of
email and voicemail must be merely the beginningUnified Messaging
needs to do a lot more than just that if it is to deserve its
name.
Perhaps we need to define "messaging" as
communication that does not occur in real time. In other words,
when you send a message, you expect that the reply may take
moments, minutes, hours, or even days to arrive. You compose what
you wish to say, and your audience is expected to compose a
reply.
Contrast this with conversing, which happens in
real time. When you talk to someone on a telephone connection, you
expect no more than a few seconds' delay before the response
arrives.
Tim O'Reilly delivered a speech entitled
"Watching the Alpha Geeks: OS X and the Next Big Thing" (http://www.macdevcenter.com/pub/a/mac/2002/05/14/oreilly_wwdc_keynote.html),
in which he talked about someone piping IRC through a
text-to-speech engine. One could imagine doing the reverse as well,
allowing us to join an IRC or Instant Messaging chat over our Wi-Fi
phone, our Asterisk PBX providing the speech-to-text-to-speech
translations.
11.4.6. Peering
As monopoly networks such as the PSTN give way
to community-based networks like the Internet, there will be a
period of time where it is necessary to interconnect the two. While
the traditional providers would prefer that the existing model be
carried into the new paradigm, it is increasingly likely that
telephone calls will become little more than another application
the Internet happily carries.
But a challenge remains: how to manage the
telephone numbering plan with which we are all familiar and
comfortable?
11.4.6.1. E.164
The ITU defined a numbering plan in their E.164
specification. If you've used a telephone to make a call across the
PSTN, you can confidently state that you are familiar with the
concept of E.164 numbering. Prior to the advent of publicly
available VoIP, nobody cared about E.164 except the telephone
companiesnobody needed to.
Now that calls are hopping from PSTN to Internet
to who-knows-what, some consideration must be given to E.164.
11.4.6.2. ENUM
In response to this challenge, the IETF has
sponsored the Telephone Number Mapping (ENUM) working group, the
purpose of which is to map E.164 numbers into the Domain Name
System (DNS).
While the concept of ENUM is sound, it requires
cooperation from the telecom industry to achieve success. However,
cooperation is not what the telecom industry is famous for, and
thus far ENUM has foundered.
11.4.6.3. e164.org
The folks at e164.org are trying to contribute to the
success of ENUM. You can log on to this site, register your phone
number, and inform the system of alternative methods of
communicating with you. This means that someone who knows your
phone number can connect a VoIP call to you, as the e164.org DNS
zone will provide the IP addressing and protocol information needed
to connect to your location.
As more and more people publish VoIP
connectivity information, fewer and fewer calls will be connected
through the PSTN.
11.4.6.4. DUNDi
Distributed Universal Number Discovery (DUNDi)
is an open routing protocol designed to maintain dynamic telecom
routing tables between compatible systems. While Asterisk is currently
the only PBX to support DUNDi, the openness of the standard ensures
that anyone can implement it.
DUNDi has huge potential, but it is very much in
its infancy. This is the one to watch.
11.4.7. Challenges
As is true with any worthwhile thing, Asterisk
will face challenges. Let's take a glance at what some of them may
be.
11.4.7.1. Too much change, too few
standards
These days, the Internet is changing so fast,
and offers so much diverse content, that it is impossible for even
the most attentive geek to keep on top of it all. While this is as
it should be, it also means that an enormous amount of technology
churn is an inevitable part of keeping any communications system
current.
11.4.7.2. VoIP spam
Yes, it's coming. There will always be people
who believe they have the right to inconvenience and harass others
in their pursuit of money. Efforts are underway to try and address
this, but only time will tell how efficacious they will be.
11.4.7.3. Fear, uncertainty, and
doubt
The industry is making the transition from
ignorance to laughter. If Gandhi is correct, we can expect the
fight to begin soon.
As their revenue streams become increasingly
threatened by open source telephony, the traditional industry
players are certain to mount a fear campaign, in hopes of
undermining the revolution.
11.4.7.4. Bottleneck engineering
There is a rumor making the rounds that the
major network providers will begin to artificially cripple VoIP
traffic by tagging and prioritizing the traffic of their premium
VoIP services and, worse, detecting and bumping any VoIP traffic
generated by services not approved by them.
Some of this is already taking place, with
service providers blocking traffic of certain types through their
networks, ostensibly due to some public service being rendered
(such as blocking popular file-sharing services to protect us from
piracy). In the United States, the FCC has taken a clear stand on
the matter and fined companies that engage in such practices. In
the rest of the world, regulatory bodies are not always as
accepting of VoIP.
What seems clear is that the community and the
network will find ways around blockages, just as they always
have.
11.4.7.5. Regulatory wars
The recently departed Chairman of the United
States Federal Communications Commission, Michael Powell, delivered
a gift that may well have altered the path of the VoIP revolution.
Rather than attempting to regulate VoIP as a telecom service, he
has championed the concept that VoIP represents an entirely new way
of communicating and requires its own regulatory space in which to
evolve.
VoIP will become regulated, but not everywhere
as a telephony service. Some of the regulations that may be created
include:
Presence
information for emergency services
-
One of the characteristics of a traditional PSTN
circuit is that it is always in the same location. This is very
helpful to emergency services, as they can pinpoint the location of
a caller by identifying the address of the circuit from which the
call was placed. The proliferation of cell phones has made this
much more difficult to achieve, since a cell phone does not have a
known address. A cell phone can be plugged into any network and can
register to any server. If the phone does not identify its physical
location, an emergency call from it will provide no clue as to the
where the caller is. VoIP creates similar challenges.
Call monitoring
for law enforcement agencies
-
Law enforcement agencies have always been able
to obtain wiretaps on traditional circuit-switched telephone lines.
While regulations are being enacted that are designed to achieve
the same end on the network, the technical challenge of delivering
this functionality will probably never be completely solved. People
value their privacy, and the more governments want to stifle it,
the more effort will be put toward maintaining it.
Anti-monopolistic practices
-
These practices are already being seen in the
U.S., with fines being levied against network providers who attempt
to filter traffic based on content.
When it comes to regulation, Asterisk is both a
saint and a devil: a saint because it feeds the poor, and a devil
because it empowers the phrackers and spammers like nothing ever
has. The regulation of open source telephony may in part be
determined by how well the community regulates itself. Concepts
such as DUNDi, which incorporate anti-spam processes, are an
excellent start. On the other hand, concepts such as Caller
ID-spoofing are ripe with opportunities for abuse.
11.4.7.6. Quality of Service
Due to the best-effort reality of the
TCP/IP-based Internet, it is not yet known how well increasing
real-time VoIP traffic will affect overall network performance.
Currently, there is so much excess bandwidth in the backbone that
best-effort delivery is generally quite good indeed. Still, it has
been proven time and time again that whenever we are provided with
more bandwidth, we figure out a way to use it up. The 1-MB DSL
connection undreamt of 5 years ago is now barely adequate.
Perhaps a corollary of Moore's Law will apply to network
bandwidth . QoS may become moot, due
to the network's ability to deliver adequate performance without
any special processing. Organizations that require higher levels of
reliability may elect to pay a premium for a higher grade of
service. Perhaps the era of paying by the minute for long-distance
connections will give way to paying by the millisecond for
guaranteed low latency, or by the percentage point for reduced
packet loss. Premium services will offer the five-nines reliability the traditional
telecom companies have always touted as their advantage over
VoIP.
11.4.7.7. Complexity
Open systems require new approaches toward
solution design. Just because the hardware and software are cheap
doesn't mean the solution will be. Asterisk does not come out of
the box ready to run; it has to be designed and built, and then
maintained. While the base software is free, and the hardware costs
will be based on commodity pricing, it is fair to say that the
configuration costs for a highly customized system will be a
sizeable part of the solution costsin many cases, because of its
high degree of complexity and configurability, more than would be
expected with a traditional PBX.
The rule of thumb is generally considered to be
something like this: if it can be done in the dialplan, the system
design will be roughly the same as for any similarly featured
traditional PBX. Beyond that, only experience will allow one to
accurately estimate the time required to build a system.
There is much to learn.
11.4.8. Opportunities
Open source telephony creates limitless
opportunities . Here are some of the
more compelling ones.
11.4.8.1. Tailor-made private
telecommunications networks
Some people would tell you that price is the
key, but we believe that the real reason Asterisk will succeed is
because it is now possible to build a telephone system as one would
a web site: with complete, total customization of each and every
facet of the system. Customers have wanted this for years. Only
Asterisk can deliver.
11.4.8.2. Low barrier to entry
Anyone can contribute to the future of
communicating. It is now possible for someone with an old $200 PC
to develop a communications system that has intelligence to rival
the most expensive proprietary systems. Granted, the hardware would
not be production-ready, but there is no reason the software
couldn't be. This is one of the reasons why closed systems will
have a hard time competing. The sheer number of people who have
access to the required equipment is impossible to equal in a closed
shop.
11.4.8.3. Hosted solutions of similar
complexity to corporate web sites
The design of a PBX was always a kind of art
form, but before Asterisk, the art lay in finding creative ways to
overcome the limitations of the technology. With limitless
technology, those same creative skills can now be properly applied
to the task of completely answering the needs of the customer. Open
source telephony engines such as Asterisk will enable this. Telecom
designers will dance for joy, as their considerable creative skills
will now actually serve the needs of their customers, rather than
be focused on managing kludge.
11.4.8.4. Proper integration of
communications technologies
Ultimately, the promise of open source comes to
nothing if it cannot fulfill the need people have to solve
problems. The closed industries lost sight of the customer, and
tried to fit the customer to the product.
Open source telephony brings voice
communications in line with other information technologies. It is
finally possible to properly begin the task of integrating email,
voice, video, and anything else we might conceive of over flexible
transport networks (whether wired or wireless), in response to the
needs of the user, not the whims of monopolies.
Welcome to the future
of telecom!
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