Delaware gives one voice to VOIP

As states go, Delaware is not that big. But it operates a large, distributed enterprise with a fragmented telephone system.

For several years, the state has had islands of voice-over-IP telephone service riding on a statewide backbone. Now it is moving to take fuller advantage of VOIP by enabling centralized management and unified communications.

The Multiprotocol Label Switching backbone from Verizon, which enabled IP telephony, is managed by the state’s Technology and Infrastructure Department. The department has acted as an integrator, working with state agencies and Verizon to define needs and select products to introduce the new technology.

That has resulted in a variety of platforms being used separately. In 2007, the department introduced Cisco CallManager for call processing, which gave the IP office more control over the systems and cut some costs.


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“We could eliminate the huge installation costs the vendor was charging,” said Mark Cabry, the department’s lead telecom engineer.

But there still was no common statewide dialing plan. Each agency had its own voice mail system, maintained its own equipment and purchased its own service, which limited both savings and the ability to expand the system.

“We wanted to have the system be able to talk across agencies,” Cabry said.

Session controllers

The solution was to use Session Border Controllers to unify the system and handle signaling between the enterprise and the carrier for setting up and tearing down IP telephony calls.

The SBCs terminate and reoriginate every session so that packets from different vendors such as Cisco and Avaya are compatible and every piece of equipment does not have to be reconfigured. It not only handles the VOIP carrier connection but enables VOIP communication among agencies without going out to the carrier network.

“It’s what made the system successful,” Cabry said.

Moving telecommunication to IP offers several advantages, including the ability to unify voice, video and text on a single platform, limit infrastructure needed to support communications, simplify management and cut costs. The legacy H323 VOIP protocol is being replaced by the Session Initiation Protocol (SIP), but getting all equipment in a large enterprise to interoperate and send traffic to a common IP backbone can be a challenge.

“Most VOIP implementations today are islands unto themselves,” said Carl Blume, director of enterprise solutions at Acme. “That’s the case with Delaware. They are planning to move all of the employees and all of the departments to a centralized architecture.

Centralize to save

Delaware is using two Enterprise SBCs located at separate data centers for redundancy, but the key to realizing cost efficiencies is centralization. By bringing all telephone connections within the enterprise to a central site and a backup one, internal communications do not have to go outside the enterprise and onto the carrier’s network, and external communications are sent to the carrier via a single large pipe rather than over multiple links at separate agencies.

SIP trunking service from the service provider links internal VOIP traffic to the public-switched telephone service via the Internet. When traffic is handled this way carriers forgo toll charges for telephone traffic over their networks, creating a cost savings for the customer and additional business opportunities for the carrier.

“The [carriers] need to do this to be competitive,” Blume said. “IP allows them to offer lots more services than they could over a [Time Division Multiplexing] network,” used in traditional circuit switching.

PBS direct

Enterprise Session Border Controllers from Acme Packet allow PBXs in each agency to talk directly to each other without going onto the Verizon network. The service is being offered to 20,000 of the state’s 40,000 network users, about 10,000 of whom have adopted it. New users are being brought gradually, and Cabry said the rest probably would be brought online within three or four years.

As agencies are brought onto the new system, the Technology and Information Department assumes the role of the internal phone service provider, doing the build-out and management and billing the agencies for services. It allows the department to consolidate the separate shops overseeing telecom under a single roof.

“As agencies are ready, as the service contracts come up, we go in and bring them online with SIP,” he said.

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