The E9-1-1 Softphone Locator (ESL) is software that allows West Safety Services’ Emergency Gateway (EGW) to automatically track the location of on-campus soft phones. It also enables E9-1-1 support for many advanced unified communications features such as shared line appearance, extension mobility, concurrent logins, and shared workspaces
THE ESL AND THE EGW
The connection between IP softphones and the EGW is HTTP/HTTPS. There are only two possible types of communication:
- When the ESL sends a soft phone’s provisioning data to the EGW
- When the ESL requests the latest instruction set from the EGW (at first run, or if the EGW detects that a newer instruction set is available)
Automatic Soft Phone Tracking
The ESL updates the EGW with a soft phone’s unique provisioning data (e.g. MAC, IP address, BSSID, extension) each time an endpoint is activated or moves on the network, and at pre-configured intervals. The EGW references this data to a layer 2, layer 3, or Wireless LAN network map to determine the location of the phone.
Support for Advanced Unified Communications Features
Unified communications features such as shared line appearance, extension mobility, concurrent logins, and shared workspaces can be problematic for E9-1-1. Unless a unique identifier is maintained for each soft phone, it is possible that the wrong location will be presented to the PSAP when an endpoint dials 9-1-1.
The ESL enables the EGW to successfully maintain unique identifiers for IP soft phones. Regardless of the logged in user profile, the IP softphone can be located based on the mapping between the layer 2/layer 3 address or wireless access point of the phone and the provisioned emergency location.