ESA for Existing Access/DLC Systems

When Public Safety Matters...

Digital Loop Carriers (DLCs) or next-generation access systems such as BLCs are excellent devices for terminating subscriber access lines, reducing loop plant or providing concentration of access lines. However, most DLCs also represent a critical point of failure in a carrier's network because if the link between the host switch and the DLC is severed the DLC will be unable to complete any local calls including emergency 911 calls. Today, over half of all access lines in the United States are terminated on DLCs, few of which have any back up or fail-safe switching capability. This represents a large and potentially critical point of failure in the PSTN and a public safety concern for all carriers.

The addition of the Aztek Networks' 5000S ESA switch to an existing DLC location ensures that all subscribers served from that DLC have a back-up switching solution in the event of a loss of connectivity to the host central office switch. This allows for a higher level of public safety with fewer network outages and continuous access to local emergency responders. The Aztek 5000S is based on open standards so it will interoperate with any existing GR-303 DLC system. The 5000S is compact (only 1RU high), hardened and produces little heat so it can be installed in an existing field cabinet or carrier end office. The 5000S implementation is seamless and introduces no additional point of failure into the network architecture. Even if the power is cut to the 5000S system it does not interupt the normal flow of traffic between the access system and the host switch.

No more Second Class Citizens

An Aztek's ESA switch offers installed DLC-based subscribers the same level of reliability and access to emergency services as subscribers connected to a traditional Class 5 host or remote switch. The Aztek ESA switch monitors the link between the access system and the central office host switch, remaining entirely passive until there is a failure in the link. While the ESA switch is in monitor mode, all calls are switched by the central office host and all 911 calls are routed to a regional public safety answering point (PSAP) where operators dispatch appropriate local emergency responders. If the switch link fails, the Aztek ESA system becomes active and completes all local calls. Any 911 calls made during this time are routed by the Aztek ESA system directly to local emergency responders. Once the central office link is restored the ESA system reverts to passive monitor mode. The Aztek 5000S will monitor and interoperate with any standards-based GR-303 or IP access system.