Steve Carter, Senior Product Manager for XO's SIP Trunking services describes the 9 most important factors to consider when deploying E911 service for enterprise VoIP.

1. E911 VoIP Essentials for
Enterprise Deployments
By: Steve Carter, Sr. Product Manager - XO Communications
xo.com

2. Ensure E911 Service for Enterprise VoIP Deployments
A Guide for Distributed VoIP Environments
Contents
Introduction 3
The Evolution of E911 3
Legal Requirements for E911 for VoIP Service 4
E911 for Enterprise VoIP 4
Integrating Private Switch/Automatic Location Identification 5
Fixed vs. Nomadic 911 6
Weighing the Options 6
Conclusion 7
About XO® Enterprise SIP 7
About XO Communications 8
About the Author 8
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Introduction
Deploying VoIP across multiple business locations is a great way to simplify and streamline
“An estimated 240 million
your distributed network and reduce costs, but how does a business provide E911 effectively
calls are made to 9-1-1 in the across the enterprise and what are the legal requirements?
U.S. each year. According
to the FCC, one-third are Today’s Voice over IP-enabled, Internet-based phones offer multiple features for convenience
of use that allow callers to use phones from virtually any Internet connection. While this
wireless calls; in many technology has many benefits for end users, it has created many challenges for emergency
communities, it is one-half or communications call centers that were designed to receive calls from landline phone services
more of all 9-1-1 calls.” associated with a fixed address. So, how does a carrier provide E911 services to remote
locations; and what are the legal requirements for providing back up and E911?
This paper explains E911 service as it relates to distributed Voice over IP phone systems and
Source: National Emergency
networks. The objective of this paper is to help inform multi-location businesses interested in
Number Association, 9-1-1
migrating to VoIP services about the evolution of E911, including their legal requirements, the
Statistics, www.nena.org
difference between fixed and nomadic E911 service, and other key considerations; and also
provides examples on how to properly configure E911 in the multi-location VoIP environment.
The Evolution of E911
Traditional 911 Service routes 911-dialed calls to a Public Safety Answering Point (PSAP),
allowing callers to quickly request emergency service from emergency personnel. PSAPs
are also known as the emergency call centers responsible for answering calls made to an
emergency telephone number (typically 911) for police, fire, rescue, and ambulance services.
Enhanced 911 or E911 utilizes additional information in processing a 911 call—the telephone
number or Automatic Number Identification (ANI) and the caller’s address or Automatic
Location Information (ALI). This information allows a 911 call to efficiently route to the
appropriate PSAP and gives the emergency dispatch personnel critical information about
the caller’s location. The Federal Communications Commission (FCC) requires caller location
capability from all phone companies where the PSAP is able to accept this technology.
Traditional telephone, wireless and VoIP service providers are all required to provide
E911 where it is available—which is the vast majority of the country. The format and rules
associated with providing E911 service are different for each technology and present different
challenges.
When early adopters of Internet-based phones demanded capabilities similar to wireless, the
need for 911 for VoIP entered the picture. In 2005, the FCC began to require interconnected
VoIP Service Providers to provide E911 service for their subscribers. With E911, 911 calls
made over VoIP networks connect to the existing nationwide network of emergency PSAPs
and automatically transmit the caller’s phone number.
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4. How to Ensure E911 Service for Enterprise VoIP Deployments
Legal Requirements for E911 for VoIP Service
The FCC requires that all Interconnected VoIP Services Providers provide 911 services,
and deliver all 911 calls to the caller’s local emergency operator. This is not an optional
feature of a VoIP provider’s service; it is a requirement. Congress reinforced the 2005
FCC rules in 2008 when it passed the NET 911 Improvement Act. With this Act, Congress
gave the FCC additional authority to require VoIP providers to meet these requirements. In
many cases, VoIP providers began requiring enterprises to purchase separate, additional
voice trunks, like Basic Business Lines (BBLs) or Primary Rate Interface ISDN lines (PRIs),
to route E911 calls to the caller’s local emergency operator. Some providers, however,
have structured their networks and solutions so that 911 calls can be routed and the
proper address information can be collected and delivered from remote sites—eliminating
the need for excess voice lines or trunks. Therefore, it is important for enterprises to
An estimated 79% of
carefully consider the capabilities of service providers with respect to E911 services.
American businesses will
be using VoIP services by E911 for Enterprise VoIP
2013, compared to only 42%
For enterprises with company-wide, centralized SIP trunking solutions that virtually
penetration at the end of
connect branch locations over an MPLS-based network, there is an increase in
2009. complexity of delivering E911 calls to the correct PSAP. For example, an enterprise has
its headquarters office and SIP connection in New York. The company also has a branch
office in Chicago that connects via enterprise WAN to the New York SIP trunk. Imagine
Source: InStat Research, an E911 call from an employee in a life-threatening incident at the Chicago branch office.
VoIP Penetration Forecast That call must reach the local Chicago emergency communications system quickly. The
market alert, February 2, VoIP E911 call, however, routes through the New York office PBX and—if not properly set
2010. www.instat.com up—could easily look like a New York call and be misrouted to a New York emergency
dispatch call center. The consequences could be devastating, even fatal if the E911 call
isn’t routed properly.
Careful planning and proper service provisioning helps to ensure phone users in all
Chicago Public Service
Answering Point (PSAP) Branch #1
Chicago
312-NXX
Chicago Street
Chicago, IL
Other
Branches
PSTN
Carrier
Network
New York
212-NXX
Critical Carrier Responsibilities:
Deliver Chicago Branch 911 call
from NY to the proper Chicago
PSAP. Also to ensure that Chicago
PSAP has Address Info for Chicago
Branch in their E911 database.
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locations have accurately set up E911 capabilities. To provide E911 service to distributed users on
a centralized, shared SIP trunk, the caller’s telephone number must be provisioned so that the E911
service is programmed to ring to the callers assigned local emergency dispatch call center, rather
than to a center miles away, across the region or across the country.
Because enterprise SIP solutions rely on a Wide Area Network (WAN) service—such as an MPLS
IP-VPN, Frame Relay or Private Line service—to provide the local connection to the centralized SIP
service, E911 service is provided as long as the enterprise doesn’t lose connectivity for the WAN.
As part of an overall enterprise Business Continuity and Disaster Recovery plan, most enterprises
seek to provide an alternate means of contacting emergency services in the event of an interruption
at any single point in their network. It is becoming more common for PSAPs to either create
redundancy in the form of back-up 911 centers or establish relationships with neighboring PSAPs
to share resources in the event of an interruption.
Another important feature to look for in a potential enterprise VoIP solution includes Business
Continuity and Disaster Recovery protection that automatically provides a failover solution for
incoming and outgoing calls in the event a centralized PBX or its connection becomes unavailable.
Only a handful of service providers offer failover and backup solutions to keep communications
running in the event of such an outage. They vary in areas such as capacity, pricing and billing, and
should be evaluated carefully.
Integrating Private Switch/Automatic Location Identification
Enterprise networks are highly complex. The advanced nature of their network designs demand
an E911 structure that directs emergency services not just to a specific location, but also pinpoint
exactly where the E911 call originated in the building. In fact, some jurisdictions require buildings
and campuses of a certain size to provide more specific Automatic Location Identification (ALI)
information to emergency operators.
Generally, when 911 is dialed from an individual’s desk, the caller ID delivered to the emergency
communications system reads as the company’s main phone number associated with the PBX—not
the individual’s direct dial number or phone extension. In a life-or-death situation, the lack of a more
specific telephone extension and a more precise location information could prove fatal.
To address this problem, Private Switch/Automatic Location Identification (PS/ALI)—which is often
available as a separate feature, can be integrated into enterprise SIP solutions. PS/ALI service goes
one step further by providing additional location information to the local emergency operators, such
as the exact floor or office number. This additional information can significantly reduce response
times by helping dispatchers find the exact location of the caller.
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6. How to Ensure E911 Service for Enterprise VoIP Deployments
Fixed vs. Nomadic 911
In addition to all of the aforementioned solutions for E911 services, it is important for enterprises
to understand the distinctions between fixed E911 solutions for physical locations and nomadic
VoIP 911 solutions for users who are connecting from an Internet phone, soft phone or adapter
into a broadband connection anywhere, that can be moved at any time by the user.
Nomadic 911 users require a different solution from a fixed-IP E911 solution because the VoIP
service provider normally delivers the service to a stationary location. In short, providers that
offer enterprises a nomadic E911 capability enable employees to move their phones and still
get the proper address information transmitted to the PSAP, as long as the nomadic VoIP
user keeps their information up to date. Updated information must be provided by the user via
location update functionality provided by the service provider.
Weighing the Options
Not all VoIP providers offer a hardened enterprise SIP solution that can accurately identify the
location of E911 calls from each office and provide automatic failover solutions without addi-
tional costs. It’s important for enterprises considering a migration to a more efficient VoIP
infrastructure to fully understand how E911 will be configured by a potential service provider
to address multiple office locations.
As an example of this level of service, providers such as XO Communications have invested
in building connections to all emergency communications systems—or PSAPs—in its national
VoIP footprint, and also has built the service provisioning infrastructure to associate the
telephone numbers to the correct PSAP without requiring the customer to purchase any other
local PSTN lines.
XO also provides a state of the art failover solution that utilizes idle capacity at one SIP trunk
location to process calls from another location—seamlessly. This feature provides the added
confidence that calls can still be completed in the event of an interruption within the network.
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Conclusion
Enterprises must carefully consider how a proposed SIP trunking solution will fully
address E911 needs. And whatever service the company selects, it’s important for
organizations to:
99 Promptly update address information for any locations when they move; and
99 Clearly understand E911 implications and the capabilities and limitations of a chosen
provider as it relates to E911 service
Advantage of SIP Trunking for the Beyond legal concerns, inefficient provisioning of E911 services that lead to
Enterprise purchasing more lines or trunks can defeat the purpose of a converged
VoIP solution.
Multi-location organizations can enjoy
many benefits after migrating to an As a society, U.S. citizens and businesses alike benefit from the fact that individuals
enterprise-wide SIP trunking solution, can simply key three digits on their telephone keypads to reach emergency
including: services. The FCC and Congress have protected individuals by making it clear that
businesses and their communications service providers can’t take away that safety
• Reduced operating costs by eliminating
multiple carriers and excessive voice lines at
net. Yet there are complexities of the language of the law that could create confusion
each location and slow an organization’s decision to adopt new SIP trunking technology.
• Improved network efficiency by using idle Enterprises should not let the complexity of regulatory rules and requirements
bandwidth at one location for other branch
keep them from adopting the right technology solution. The right solution for your
locations, and by carrying voice and data over
a single Wide Area Network business is available, as long as you equip yourself with the right information and
• Reduced capital expenditures by sharing a ask some key questions of your service provider.
centralized PBX across the enterprise
Key questions to ask potential service providers:
Note: For more on business benefits,
1. Can E911 be seamlessly integrated into the overall service solution?
consult the white paper “SIP for 2. Will additional Plain Old Telecom Services (POTS) at each location be required to ensure sustained
the Enterprise: Key Advantages & coverage?
Benefits”. 3. Will the solution route the calls to the caller’s local emergency responder—rather than the central-
ized SIP trunk—accurately and without adding third party solutions?
About XO® Enterprise SIP
XO Communications has expertise in enterprise networking, particularly with
next-generation network architectures, and makes for a powerful partner for
your enterprise connectivity needs. The XO® Enterprise SIP solution provides a
complete, end-to-end option for organizations with the challenge of interconnecting
multiple geographically-dispersed locations. With over nine years’ experience in
owning and operating a VoIP-based solution, XO carries over 25 Billion VoIP minutes
annually and serves over 25,000 businesses with VoIP services. In addition to
providing integrated voice and data services to businesses and enterprises, XO also
powers many other telecom providers’ VoIP infrastructure with high volume VoIP
Origination and Termination services.
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8. How to Ensure E911 Service for Enterprise VoIP Deployments
About the Author
Steve Carter is Senior Product Manager of XO’s Enterprise SIP solution. Steve led the launch of
XO’s Business Services IP Trunking products and developed new and innovative VoIP capabilities
for enterprises. His efforts have helped XO win 2007 and 2009 Internet Telephony Product-of-the-
Year Awards for both XO’s SIP and Enterprise SIP solutions. Prior to joining XO, Steve led Product
Development of VoIP services at Primus Communications, targeted specifically for enterprise and
carrier markets. Steve’s expertise includes over 20 years of Product Development and Management
in Wireless, Data, Telecom, and I/P services.
For additional information, please visit XO Communications at www.xo.com or call directly at
888-718-7595 for more information or a complimentary service evaluation.
XO911WP-0412
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XO, the XO design logo, and all related marks are trademarks of XO Communications, LLC.

9. About XO Communications
XO Communications is a leading nationwide provider of advanced broadband communications
services and solutions for businesses, enterprises, government, carriers and service providers. Its
customers include more than half of the Fortune 500, in addition to leading cable companies, carri-
ers, content providers and mobile network operators. Utilizing its unique combination of high-capacity
nationwide and metro networks and broadband wireless capabilities, XO Communications offers
customers a broad range of managed voice, data and IP services with proven performance, scalability
and value in more than 85 metropolitan markets across the United States. For more information, visit
www.xo.com.
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© Copyright 2012. XO Communications, LLC. All rights reserved.
XO, the XO design logo, and all related marks are trademarks of XO Communications, LLC. XO911WP-0412