WHITE PAPER NON-GEOGRAPHIC E-911 SERVICES FOR SIP TRUNKING

Transcription

1 WHITE PAPER NON-GEOGRAPHIC E-911 SERVICES FOR SIP TRUNKING

2 NON-GEOGRAPHIC E-911 SERVICES FOR SIP TRUNKING Executive Summary Voice over Internet Protocol (VoIP) is emerging as the new standard for voice connectivity. It is more flexible, cost-efficient, and feature-rich, and provides support for new levels of employee productivity by enabling new applications that are the foundation for unified communications. Recognizing these benefits, there are many service providers delivering VoIP services over Session Initiation Protocol (SIP) trunks. Providing correct 911 call-routing data over VoIP has proven to be difficult. However, recognizing that more users are moving to VoIP, the Federal Communications Commission (FCC) dictated that VoIP Service Providers (VSPs) must support 911 services. In addition, many other government bodies have passed regulations that require businesses to provide 911 services in their workplaces. With the growth of a new mobile workforce, continued IT budget concerns, and the risk of significant penalties for failure to comply with new 911 legislation, enterprise managers need information to help them decide which 911 services are best for protecting their employees from harm and their business from fines and litigation. This paper provides an overview of how the 911 system operates and the alternatives for providing enhanced 911 services with VoIP and SIP trunks. The History of 911 The 911 network is a vital part of our nation s emergency response and disaster preparedness system. In 1999, the United States Congress directed the FCC to make the universal emergency number in the United States for all telephone services. More than an estimated 240 million calls are made to 911 in the U.S. each year. However, there is no single national 911 system. Instead, the 911 systems are comprised of over 6,000 individual Public Safety Answering Points (PSAPs). Each PSAP is locally managed, typically at the city or county level. Trained dispatchers within the PSAP receive the 911 calls and notify the appropriate first responders (police, fire, ambulance). Microsoft E-911 Support Microsoft Lync Server 2010 and 2013 include support for Enhanced 911. This feature can identify location information by the wireless access point (WAP), Basic Service Set Identifier (BSSID), MAC address, IP version 4 (IPv4) subnet, Link Layer Discovery Protocol (LLDP) switch or LLDP switch port, and then map these to a physical mailing address. Lync will then pass on a Presence Information Data Format - Location Object (PDIF-LO) that identifies the physical location of a caller during emergency calls to a network provider enabled with E-911. To support this critical functionality, Level 3 has teamed with Microsoft to develop a solution that couples Lync capabilities to track end-user location information with Level 3 s SIP Trunking service (Voice Complete) and our nationwide, owned and operated E-911 network. Level 3 s Voice Complete SIP trunking solution with Non-Geographic E-911 is a single-vendor solution that uses the location information passed in the SIP call to determine the appropriate local public safety answering point (PSAP) to route the call and location address information, including floor- and suite-level data, to the emergency operator. Microsoft Lync Server 2010/13 provide a complete set of enterprise-grade voice features, including Enhanced 911 calling for North America. When 911 was first implemented, only basic 911 services were available; the distressed caller had to tell the dispatcher where he or she was calling from. Even today, the 911 caller s location and phone number might not always be automatically available to the PSAP dispatcher. Though the Enhanced 911 (E-911) service is designed to automatically display the telephone number and physical location of the 911 caller on the emergency dispatcher s screen, not all carriers provide the required data to support E-911. This is particularly true for wireless and VoIP carriers that have to solve for Non-Geographic phone users. 1

3 SIP Trunking and VoIP Voice over IP (VoIP) refers to an application in which voice communications are carried over an IP network. The connection can be provided over any type of IP network, including the Internet. Business-class VoIP services usually rely on private IP networks. SIP trunks are used to provide VoIP services for multi-line telephone systems. SIP trunks are used in place of traditional TDM trunks (also known as T1 lines). TDM trunks use older, time division multiplexing technology and provide a fixed number of channels or lines (typically 23) per trunk. Businesses are usually forced to purchase these services on a trunk-by-trunk basis. SIP trunks use IP technology. Instead of having a fixed predefined number of channels, SIP trunks are usually sold by bandwidth increments and are sized to support a certain number of simultaneous calls. An enterprise can divide the simultaneous calls across multiple locations, allowing for much more efficient, cost-effective use of their phone services. 911 and a Mobile Workforce A 911 call placed from a business usually originates from a multi-line telephone system. Typically, the main phone system is centrally located and could even serve multiple office buildings. Often, the address information is correlated to the location of the telephone system, not to location of where the 911 call originates. In a campus environment, for example, this could result in the first responders showing up at the data center instead of where help was needed. With traditional multi-line systems that rely on TDM trunks, this problem is limited to a single metropolitan area. However, with technologies like VoIP and unified communications, a single multi-line system could serve an entire enterprise that has offices established thousands of miles apart. A 911 call that originates in Los Angeles could easily be directed to a PSAP in New York City. This problem is amplified with an increasingly mobile workforce. It s not unusual for today s corporate worker to spend part of their day in their office, in several meeting rooms, at a vendor s office and with a customer with all of these locations spread across multiple buildings and possibly in different cities. E-911 and VoIP Determining the geographic location for the origination of a 911 call is not a new problem. The FCC created a series of rules addressing the need to support Non-Geographic E-911 services over wireless phones in These rules defined two phases of compliance that wireless carriers were to comply with upon request by a PSAP. Phase I required wireless carriers to provide latitude and longitude data derived from the location of the wireless towers used to initiate the E-911 call. In Phase II, wireless carriers were to provide the latitude and longitude within 100 meters of the actual wireless phone placing the call. Determining the location of the device within this tolerance solved the issue of finding Non-Geographic wireless devices and mobile users, but it did not solve the issue of providing that data to the thousands of PSAPs that needed it, since it was only provided by the wireless carrier upon request. In order to facilitate the dynamic nature of Non-Geographic E-911, local governments established Automatic Location Identification (ALI) databases. These databases allowed the PSAP to look up the precise location of a caller by dipping the database upon receiving the E-911 call, the wireless provider looked up the location of the caller, connected the caller to the correct PSAP based on their location, and simultaneously sent the location data to the appropriate ALI database. The PSAP could then dip the ALI database to retrieve the location data and relay it to the dispatcher. The introduction of VoIP created new issues. The very nature of IP allows for a level of mobility that eclipses that of wireless phones. A typical wireless provider may have thousands of cell towers in their network, but there are more than 4.3 billion possible 1

4 IP addresses in the Internet today. Early VoIP Service Providers did not provide 911 services, but in 2005, the FCC ruled that all VoIP service providers must support E-911. In response, many VSPs created systems that supported static E-911 but did not address the true mobility challenge that VoIP presented. Static and Non-Geographic E-911 Static E-911 services are designed to support E-911 users that use stationary instruments. These services allow the end user to predefine the location information for each end instrument, typically through a carrierprovided web portal. The VoIP carrier correlates the location information provided by the subscriber to the user s IP address to populate the VoIP Positioning Center (VPC) database with the correct location data. Data is then sent from the VPC database to the correct ALI database. Non-Geographic E-911 for VoIP services requires a new level of sophistication. With the introduction of new types of VoIP-enabled services, such as unified communications, an end user s calling location could change rapidly with no corresponding change to their IP address. New VoIP client software has been developed to support VoIP calls on all sorts of mobile devices desktop phones, laptops, tablets and next-generation IP-enabled smart phones which enables mobility but also complicates locating mobile users when they are in distress. To help support this new level of mobility, several industry standards bodies proposed both new standards and extensions to old, to provide a framework in which VSPs and VoIP equipment providers could support truly Non-Geographic E-911 VoIP services. The Internet Engineering Task Force (IETF) introduced an extension to the SIP standard that allows for location data to be sent in the data flow used to establish the VoIP call. This extension to the SIP protocol defines the creation as a new data type, called the Presence Information Data Format Location Object (PIDF-LO). The PIDF-LO data is sent during the establishment of the VoIP session and can be used to dynamically transmit location data that the carrier can then use to populate the ALI database. The National Emergency Number Association (NENA) led efforts to establish an interim set of rules that defined how to connect callers in the IP domain with PSAPs supported by the existing E911 service provider network. NENA also recommended the i2 standard for the support of the interconnection of VoIP domains with the existing emergency services network infrastructure. It s important to note that as of 2013, many of the standards proposed are still in an interim status and not yet fully approved. Level 3 Voice Complete SIP Trunking Service with Non-Geographic E-911 Level 3 supports Non-Geographic E-911 for Microsoft Lync deployments via our Level 3 Voice Complete solution, which includes SIP Trunking service. This capability is also on the development roadmap for all non-lync Voice Complete users. We have demonstrated industry leadership by implementing the proposed PIDF-LO standard and the NENA i2 initiative, allowing Level 3 SIP Trunking customers to pass PIDF-LO data to Level 3 and VSPs to comply with the new FCC ruling. It also provides the back office infrastructure to support a truly Non-Geographic E-911 VoIP service. As an early developer of the VoIP softswitch, Level 3 is uniquely positioned as an alternative voice services provider with our end-to-end IP network. While other carriers provide their SIP trunks via their existing switched TDM networks, Level 3 is able to carry the entire SIP session without the need for any legacy TDM-based voice switching. Since 911 calling is managed in a completely different way between the two technologies, providing E-911 services from a network that uses a mixture of VoIP and TDM is very difficult. With our all-ip network, Level 3 is also able to provide direct E-911 integration between our SIP Trunking services and the VPC database (see figure 1). PIDF-LO data is placed into the SIP call flow by the company s IP multi-line phone switch (IP-PBX). Using advanced geolocation capabilities, some IP-PBXs such as Microsoft Lync can accurately determine

5 Remote Worker Branch Office Corporate Headquarters Appropriate Local Public Safety Answering Point (PSAP) Internet Home Office Soft Phone Office Phone Enterprise WAN Retail Location 911 SIP call with location info in PIDF-LO Level 3 SIP Core VoIP Positioning Center (VPC) Database the user s location. Microsoft Lync maps the network location to a physical mailing address and constructs the PIDF-LO information, which it then sends with the call to Level 3 via the company s SIP trunk on the Level 3 network. The PIDF-LO information is received at the Level 3 border controller. At this point, the PIDF-LO data is stripped from the call flow and is sent to the VPC for transmission to the ALI database. Simultaneously, Level 3 uses the caller s phone number to connect the call to the correct PSAP. The PSAP then uses the caller s phone number to dip the ALI database and find the correct address information. Alternative Non-Geographic E-911 Services for VoIP There are alternative E-911 services offered by other SIP trunking providers. Most of these services introduce significant risk and complexity into the enterprise environment. Some rely on a third-party 911 service provider, while others implement a mix of technologies. For example, one alternative uses dedicated TDM lines to provide E-911 calling. Not only does this alternative not achieve the level of mobility that the newer unified communications systems enable, this service also requires the dedicated use of separate phone lines for each geographic location where emergency services are needed. This approach could require dozens of dedicated lines in a large campus environment. As government regulations become more stringent and require location data that is accurate to the building, floor or even to a specific work zone, the number of dedicated lines and the management of the location data associated with these lines can become increasingly problematic. Summary The use of next generation VoIP for enterprise voice services is growing. Calls to 911 have become the primary connection between emergency services and the American public. As businesses look to SIP trunking as an economic alternative to traditional TDM voice, and as a tool to enable new levels of employee productivity with tools like unified communications, they need to ensure that those employees have access to E-911 services. Fortunately, new standards are being created and implemented, by carriers such as Level 3 Communications and equipment providers like Microsoft, allowing enterprises to gain the benefits of unified communications and SIP trunking, as well as provide the Non-Geographic E-911 protection their employees deserve

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