West Corporation

Posted on December 7, 2012 by West Corporation 



Better E911: Lync and the Emergency Gateway

EGWWhen Microsoft was first working on their follow-up to Office Communicator, their team reached out to us at 911 Enable to collaborate on how to provide E911 support for their new Lync platform. Out of this collaboration, Microsoft Lync included revolutionary E911 capabilities not found in other UC platforms. The Microsoft Lync clients were made to be location-aware. This meant that an E911 solution did not need to “find” the device when a call was made, because the device would send its location during a 911 call.

This location awareness is enabled by a proprietary location request made by the client to the Lync Location Information Service (LIS) at client sign-in. Since the client itself is making the request, they can be located at the device level regardless of the line appearance of the Lync client logged into that device. Locating clients at the device level is critical in the enterprise due to the use of shared lines, multiple concurrent logins, and the mobility of soft clients. This location request process enables administrators to pre-configure enterprise location data in the Lync LIS database. 911 Enable is one of the only certified Microsoft partner to interoperate with these features to provide real-time MSAG Address validation and SIP emergency call routing support for Microsoft Lync.

The native E911 support built in to Lync, combined with 911 Enable’s call routing solution, enables organizations to meet basic E911 regulatory requirements. Unfortunately, simply complying with basic E911 regulations may not be adequate to meet all the corporate E911 requirements in the Enterprise UC space. To enhance the native E911 support provided by Lync, many enterprises are choosing to install 911 Enable’s Emergency Gateway (EGW) appliance to meet all their requirements. There are many benefits to installing the Emergency Gateway appliance into the Lync environment and I have included some of the highlights below:

  • One pair of Emergency Gateway appliances can manage multiple UC vendor deployments at a time. Since Lync is still a new platform, it is very common to have a multi-vendor environment as users migrate to Lync. The EGW acts as a central E911 administration point for all your UC deployments, which greatly simplifies management and integration. It is not uncommon to have enterprise deployments that have been trying to replace their old legacy PBX for years, with many factors keeping the old beast in production much longer than expected or desired. Using the same pair of EGW appliance, both the Lync users and the old legacy users can be supported.
  • With the Emergency Gateway, administrators can easily manage E911 configuration using a simple web administration GUI instead of PowerShell applets.
  • The Emergency Gateway appliances can be automated to integrate into third-party systems using a variety of interfaces. This allows for further automation of E911 management.
  • The Emergency Gateway appliance has advanced security personnel notification capabilities. This includes enhancing the existing Lync capabilities with the ability to have security conferenced in during 911 calls, using the 911 Enable Desk Alert screen pop application, and integration into existing security CAD systems. A single pair of EGW appliances can provide the same notification capabilities across multiple UC vendor platforms, so onsite security personnel receive the same notifications regardless of which UC platform the call originated from.
  • The Emergency Gateway has advanced overlaid discovery methodologies compared to Lync, allowing administrators to customize location determination preferences to adjust to the uniqueness of their environment. This means administrators can control which network element is used to determine a location for a user. The administrator can choose any order of either MAC (switch/port), wireless BSSID, subnet, or other factors to locate the user. The Emergency Gateway also allows administrators to build “Safety Net” supernets to minimize errors in data entry, instead of Lync’s native E911 capabilities which require all device subnets to be entered one-by-one. For example, say you have one building with 10 floors and each floor has its own 10.45.xx.0/24 subnet. Each floor can be provisioned as 10.45.x.0/24 or you can provision the entire building as Additionally, the Emergency Gateway does not need to rely on third party network discovery systems to obtain MAC/switch/port data.
  • The Emergency Gateway can use any combination of E911 destination routes. The native Lync E911 support routes all the emergency calls to a certified E911 routing service such as the 911 Enable Emergency Routing Service. This may not be appropriate if you have a large number of client devices all on the same campus, served by the same Public Safety Answering Point. In these cases, the Emergency Gateway can route the calls out local gateways to be used with legacy PS-ALI solutions while routing mobile or work at home users to the Emergency Routing Service. The Emergency Gateway has been designed to route to either a local gateway or through the Emergency Routing Service.

This is just a small subset of highlights of what the Emergency Gateway brings to the Lync environment. Due to the location awareness of the clients, the Emergency Gateway can locate Lync users at a device level and not just using line-appearance. The Emergency Gateway appliance is qualified in the Microsoft Unified Communications Open Interoperability Program (UCOIP) for Microsoft Lync, as is the Emergency Routing Service. 911 Enable continues to be an active partner with Microsoft to ensure that Lync continues to provide progressive E911 support. Microsoft has done an excellent job implementing innovative E911 support capabilities and the Emergency Gateway appliance extends this functionality to provide a robust, feature-rich E911 solution.

To learn more, visit or call 1-877-862-2835.

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