voice over ip: the new reality of business telecommunications

voice over ip: the new reality of business telecommunications
Let’s face it; telecommunication is a critical part of the
business environment and always has been. The need to
communicate is crucial. The evolution of voice solutions
for the Enterprise will have to involve IP in the long term as
analog based solutions are quickly becoming obsolete.
Voice over IP (VoIP) has come a long way, improving call
control and quality immensely since its infancy. Session
Initiation Protocol (SIP) has defined a signaling standard,
resilient to the passage of time. Maturity of this technology
has created a revolutionary ripple effect, setting ubiquitous
adoption of IP Voice in motion. Metro Ethernet is going to
be a big part of making that movement a reality.
There are some distinct differences between analog voice
(POTS – Plain Old Telephone Service) and using Voice
over IP. Let’s take a minute to review them and you should
be able to see how VoIP has quickly become the superior
form of technology.
With a strong history dating back to the 19th century,
access to the Public Switched Telephone Network (PSTN)
though POTS has proven to be an instrumental part of our
society. Long gone are the days of talking over two cans
and a string!
As a circuit switched technology, there are some benefits
with POTS. When you pick up the phone, your telephone
conversation is created with a dedicated path through the
PSTN. This enables a connection as long as circuits are
available.The network was also designed to maintain a
stable, high quality level of voice quality and because of its
long history, POTS is available pretty much anywhere.
Although we are now in the age of fiber optics and
wireless service delivery, POTS is still based on the
copper medium. The core network has been upgraded
to a fiber-based infrastructure, but copper pairs are still
being used to deliver voice services to the home and
business. One POTS line means the ability to have one call
or conversation at a time, but today’s businesses demand
a better way to communicate. Time Division Multiplexing
(TDM) has made copper more efficient but not scalable
enough in the long term. Technology continues to evolve
and copper facilities are not able to keep up with demand.
Voice Over IP
Voice over IP is the solution to POTS limited capability and
growth potential. It was developed using the strengths of
POTS and the PSTN as we know it today. The dominant
standards-based signaling protocol, Session Initiation
Protocol (SIP) is similar to the signaling used in the PSTN
(SS7), as it is also responsible for setup, management and
teardown of IP voice calls. Real-time Transport Protocol
(RTP) is a UDP based method of transporting voice from
caller to call recipient. Voice quality of IP calls is modeled
after the clarity and consistency found with POTS, made
possible by using high quality codecs that are effectively
sampling and compressing audio.
VoIP is a very flexible technology with a massive amount
of potential. There are fewer infrastructure concerns, as IP
can run over multiple physical mediums, including copper,
fiber or even collective forms of wireless technology. As
long as you can route IP traffic, you can do the same with
VoIP. It is Internet Service Provider agnostic as well, which
means you can technically utilize any internet connection
to place calls across the PSTN. There is no limit on your
call capacity as long as the IP-PBX and network bandwidth
can support it. In many cases, restrictions and surcharges
on long distance calling are minimized or eliminated with IP
to IP calls that never traverse the PSTN.
Now that you know a bit about VoIP, ask yourself: Is my
business ready to take on the transition? It will have to
be at some point – the tidal wave of telecom evolution is
proving that conversion is unavoidable.
Comcast Senior Sales Engineer,
Convergence Technologies Professional (CTP)
[email protected]
A successful VoIP implementation is ultimately contingent
on the user experience. Avoiding dropped calls,
maintaining high quality audio, enabling easy inter-office
calling and maintaining usability and feature set is crucial.
As you can see, there are many factors that should be
considered. Here are some topics and questions to ask
yourself that will give you a place to start and help you
makesmart decisions.
Review Current Solution
When it comes to voice, what is working for your
company?Step back and take a holistic look at how
the current phone system complements your business;
specifically how it is utilized and what the critical functions
are.VoIP can give you all sorts of features, but ultimately
a satisfying user experience is paramount. Find out what
people like and dislike about how the current phone
system works now and you will have an idea of what to
look for in something new.
Some important things to look for here are receptionist
needs, executive management requirements and current
inbound/outbound call flow.
Physical Networking and Switching
Cat5e or better in the walls? Gig-E or 10/100 LAN? Most
IP phones have a built in switch (2 ports) so you can have
both a computer and phone connected through the same
wall jack (aka “daisy chain”). This is most often practiced
when limited wall jacks are available. If you are running a
Gig-E LAN and choose to daisy chain your workstations
through IP phones with 10/100 ports, you are limiting
your workstations to 10/100 port speed. You will also
need switches that can support 802.1q VLAN tagging and
802.1p for prioritization.
Power Over Ethernet
Are your switches able to provide Power over Ethernet
(PoE)? Utilizing PoE for capable phones is a nice way
of conserving space as it eliminates the need for big fat
AC power adapters. If you are looking to purchase new
switches, this is a good time to consider those that are
PoE capable. If you aren’t PoE-ready, AC powered PoE
injectors are an option, but should be kept in the MDF/IDF
to maintain that space saving benefit.
Multiple Locations
Do you have more than one office? If there are multiple
offices as part of this equation, you should also review
inter-office communication. The ability to extension dial
between locations is sometimes overlooked. If you choose
a system that cannot transport voice over a Metro E or
VPN network, you are looking at more trunks/lines being
tied up by these calls.
Remote Users
Are there field personnel that work from smaller satellite
offices or other types of remote locations? Teleworkers can
also impact call capacity. If a remote worker has to dial in
to the PBX just like an off network caller would, they are
also tying up call trunks/lines. It is worth having a phone
system that allows for IP and/or VPN connectivity, giving
remote workers the ability to access the system as if they
were on site and make more efficient use of resources at
the same time.
Locally Managed or Hosted PBX?
The locally managed (or premise based PBX) is a phone
system managed within your own organization, either by a
staffed telecom administrator or outsourced IT consultant.
This is a great solution for mid-size to larger organizations
because of the scalability and control over provisioning,
features, handsets and ingress/egress call processing.
Today’s IP-PBX’s can be collocated in a data center or
remote location for a Hosted PBX like feel and some added
business continuity and disaster recovery. Most
IP-PBXs can use traditional ISDN PRI or SIP trunking.
HostedPBX is a product powered by a cloud-based
software phone switch (or soft switch). This is a desired
solution for small and mid-size businesses and any
business with multiple locations because of the provider
managed provisioning and maintenance of the phone
system.Many useful features and functionality are available
to unite the desktop, mobile and telephone experience.
Disaster recovery capability of the Hosted PBX is possible
because of its cloud-based nature. Ingress call flow (auto
attendants, hunt groups), voicemail, and mobility features
are processed server-side, so if your connection to the
PSTN goes down or all call paths are full, there is minimal
impact and business continuity is maintained.
CAPEX vs. OPEX Investment
From a financial perspective, the locally managed IP-PBX
requires more initial capital expense due to purchasing all
the hardware required, licensing and support contracts.
However, the ability to use PRI or SIP trunks to reach
the PSTN translates into a more favorable cost per user
for larger organizations, which means lower operating
expenses in the long run. There are many well-known
managed hardware vendors and thanks to the open
source movement, many available Asterisk variants that
can actually reduce your initial capital expenditure costs
even further.
The initial capital investment with Hosted PBX is low, as
you are only paying for IP handsets which usually come
with some sort of warranty and repair managed by your
provider. There may be an IP gateway, but there is no
phone switch that needs to be purchased and most
often no one-time licensing fee to activate features.
The financial impact with Hosted PBX is in actuality an
operating expense. You are ultimately paying for hardware
management, virtualization of your phone system,
maintenance and transport to the PSTN. This can translate
into a lower upfront cost and predictable costs per user.
Note: Be aware of Hosted PBX providers that require
proprietary handsets. At some point, you may consider
changing providers, or liquidating the IP phones you have
to make room for upgrades. Resale value of a proprietary
handset is very low primarily due to the narrow options
for use. Choose IP phones that embrace the SIP signaling
standard, have adjustable configurations and thus
versatility in choice of provider. Consider handsets with
High Definition voice, as they provide better call clarity, a
new standard of IP voice.
Choosing a Service Provider
There are some core considerations when looking at a
service provider for your VoIP solution.
Call quality control is the most important. VoIP is a packet
switched technology and is dependent on access to the
Internet or your provider network. Voice quality and stability
are directly affected by poor network performance such as
packet loss, jitter and round-trip delay.These symptoms
cause dropped calls, low quality audio and loss of in
or outbound audio which makes provider choice very
important.You should make sure the provider can control
call quality.
Although a low price is attractive and may make a
transition easier, it isn’t always true that the rock bottom
cost option will be best in the long run. Look at value of the
provider as a whole and ask about network infrastructure
and ownership, reputation with VoIP and other business
products, how the implementation/installation process
works and other things like equipment requirements and
package options.
Service Provider Checklist
Reputation - How long in the VoIP game?
Network Infrastructure
Choice: Hosted, Trunk or a mix of both?
How call quality is maintained
Value vs Price – Cheap isn’t always good.
Total Cost of Ownership Analysis
Local, Long Distance and International Rates
Equipment Requirements
Implementation Process – How long?
Tech Support – Call and test responsiveness!
q Post Sale – Move/Add/Change/Deletes
Take a look at the checklist above for some other important
topics. The best providers will be able to answer all of
these questions easily and with a favorable response.
A Metro Ethernet Network is designed to address your
own infrastructure needs and supercharge your VoIP
deployment strategy. Long range Ethernet connectivity
between offices gives you the same level of control over
voice/data prioritization(using 802.1p) as you have locally
with superior service levels ensuring call quality. Metro
Ethernet networks can help enhance business continuity,
performance and stability for both a localized IP-PBX and
hosted PBX services.
Metro Ethernet (Metro E)
A Metro Ethernet Network can be loosely defined as
a regional extension of your Ethernet-based Local
Area Network (LAN). Its primary purpose is to connect
geographically separate sites as if they were offices
located in the same building. This means traversing the
public internet for inter-office communication is no longer
required. Couriering hard drives or tape backups from
your office to a data center or data storage provider will
become a thing of the past. Because this type of service is
Ethernet based, you will also have flexibility in the choice
of equipment and freedom to configure the network as you
see fit.
Flexibility from the equipment perspective is born from
the Ethernet nature of Metro E. Just about any piece of
networking equipment has at least one Ethernet interface.
Contrary to SONET or DS3 customer edge devices, special
interfaces are not required and therefore create a drastic
reduction of required real estate (as low as 1RU) in the
MDF/Telco Room. Making space available will not only free
up room, but can also translate to savings on cooling and
energy spent on networking equipment that is no longer
Metro E can be delivered over various types of
infrastructure, from wireline (copper and fiber) to wireless,
but the most resilient architecture is an end to end fiber
implementation. As photonic technology evolves, fiber
reveals nearly unlimited potential. Wireless service delivery
is also becoming more prevalent, as stable long range
options and multi-gig development progresses. However,
wireless service (think of 4G LTE as an example) is
ultimately dependent on a wireline network for transport;
most often of which is based on the fiber medium.
Network Design
If the network is not designed properly, VoIP will be
plagued by call quality and completion issues, as
described earlier. So, the question is whether or not to
design around complete network divergence, or converge
wherever possible.
The legacy service delivery archetype is based on
complete divergence: one connection type for voice and
one for data. Diverged VoIP services are modeled the
same way, with separate network connections used to
prevent voice and data traffic from competing with each
other. Converging voice and data over a single network
connection is a better option from a financial perspective,
but the risk of bandwidth contention is still there.
Metro Ethernet allows for a diverged solution over
converged infrastructure. A Metro Ethernet provider that
can offer managed CoS can enable diverged voice and
data VLANs over a single Ethernet Virtual Circuit (EVC).
This facilitates complete availability of bandwidth for
both voice and data. The problem with managed CoS is
the management piece; usually limited by the amount of
CoS offered. An EVC with a single VLAN and a high SLA
empowers the network administrator with the ability to use
more traffic classes than the service provider offers.
Energize the IP-PBX
Inter-office calling with premised based voice has
historically meant installation of a phone switch (PBX)
at each site. A PBX that can utilize IP on the LAN side
can use the Metro E network to transport voice traffic
between offices. This saves call capacity, since inter-office
calls behave like intra-office calls and do not tie up PRI/
SIP trunks. It also means that less equipment is required,
because there really only has to be one core phone switch
for the entire network to use. For offices that are spread
among multiple calling areas, the network can be utilized
for least-cost routing to minimize long distance charges or
even redundancy through a backup PBX at a second site.
Data Center collocation of the PBX itself is also an option,
which enables business continuity and disaster recovery as
well as giving you the feel of a cloud based phone system.
VoIP calls Utilizing a Metro Ethernet Network
Metro Ethernet
Calls to the PSTN
Site 3
With a Hosted PBX, connectivity to the Internet is a
common requirement. In order to govern call quality and
capacity, an Application Layer Gateway (ALG) is installed
at the top level of the network. The purpose of this device
is to govern Quality of Service (QoS) using Traffic Shaping,
Call Admission Control and CoS prioritization. So for a
multi-site solution, an ALG would be required at every site.
Metro Ethernet Networks turn the tables a bit. Interoffice calls do not have to traverse the public Internet
and prioritization can be controlled by the network
administrator. There really only has to be one ALG for the
entire network, as all offices can be configured to route
through it. Disaster recovery and business continuity are
accomplished by enabling data center collocation of the
ALG (as mentioned in the IP-PBX section).
In a multi provider situation, where the VoIP service
provider is a different company, Metro E can also be used
as an out-of-band network for inter-office calling and
routes to backup ALGs.
VoIP is a solution to the fading technology problem known
as analog voice. It carries most of the world’s voice traffic
today. A vast majority of advanced services we can now
appreciate as business customers are enabled using VoIP,
such as voicemail to email, click to dial, find-me-follow-me,
web based PBX administration and the like.
Before VoIP, the ability to make telephone calls required
a hard line to the PSTN. Networking was only used to
transmit data. With VoIP, telephone calls can be made
pretty much anywhere an Internet connection is available
and today, the business world is utilizing Virtual Private
Networking or extending their LAN with Metro Ethernet for
better inter-office communication.
Fiber based Metro Ethernet networks are scalable, resilient
and built to meet the needs of demanding networking
applications, which makes transition to a VoIP enabled
networking environment simpler and much more efficient.
Combined, VoIP and Metro Ethernet complement each
other very well, and together are creating a new future for
business telecommunications. Find a reliable, reputable
and responsive Metro Ethernet service provider, review all
options for implementing VoIP across the enterprise, make
informed network design decisions, and you can really
leverage the benefits here and become part of that future.
Enhance the Hosted PBX
Site 2
Inter-Office Calls
© Comcast 2012 Comcast Business Services. All Rights Reserved.
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