Helping Transport Voice Securely from Coast to Coast

Summary:

Engage Communication’s vast TDM-over-IP expertise and solutions helped ACG Systems win a federal law enforcement agency contract to transport voice across the nation. Product features and ease-of-configuration were keys to winning the GSA Schedule bid.

“Engage’s mastery of products that provide TDM-over-IP transport helped us win a competitive bid with one of the largest Federal law enforcement agencies.” 

Transporting Voice Securely Over IP

Systems Integrator ACG Systems has tapped into opportunities within federal and state governments, law enforcement agencies and the armed forces for years.

ACG’s expertise in designing telecom and networking solutions has led to numerous customer wins including one of the largest Federal law enforcement agencies.Two years ago, it won a competitive GSA Schedule bid to provide a TDM-over-IP transport solution for the agency. The solution was national in scale.

The agency’s activities cover all 50 states. Its field staff continually collects information and sends it back to a central processing site. The RFP described a solution that would ensure reliable and secure transport of voice traffic over an IP network, ease-of-implementation-and-operation, and options to minimize network bandwidth requirements. 

Configurability and Compression Both Key

ACG Systems proposed a solution featuring the Engage IP•TubeGT1, part of Engage’s circuit emulation product offering.The IP•Tube GT1 enables reliable T1/E1 voice communications over IP, ideal for the agency’s need to transport voice traffic over IP from dozens of remote sites throughout the country to a central processing location. To reduce the amount of Ethernet bandwidth necessary to handle the traffic, ACG requested that Engage configure the IP-Tubes with Lossless Data Compression.

Implementation was friction free. The agency requested several evaluation units to test. One of the key features that became apparent during testing was that the IP•Tube’s customizability allowed the agency to create a single configuration that worked at all sites. A single setting would greatly simplify and lower the cost of installation and management. After the agency validated the equipment, IP•Tubes were installed at well over 100 locations across the country.

TDM-over-IP Mastery

“Engage’s mastery of products that provide TDM-over-IP transport helped us create a solution that won us a very competitive bid with one of the largest Federal law enforcement agencies,” said ACG Systems Vice President Tim Carney. “Robust, feature-rich, easy-to-install and -operate, the IP•Tube products solve a wide variety of telecommunications problems. We continue to provide them to government customers for a variety of applications.”

Public Safety Communications Network Dramatically Increases Network Availability

A major networking company owns and operates a public safety trunked radio system serving statewide public safety agencies. The P25 radio system utilizes T1 trunks for connection between approximately 180 tower sites and three regional centers. State Police, Highway Authority, county and municipal agencies all rely on the public safety radio system for critical public safety communications.

To ensure a high availability of service, the networking company’s engineers focused on minimizing service interruptions caused by T1 outages. In the event of a T1 failure, they wanted the circuit to automatically switch to an alternate path on a different access network. Cellular, with its increasing capacity and reliability, was determined to be a viable solution for this backup path. However, next generation 3G/4G cellular networks are packet based and don’t support native T1 circuit transport. The engineers needed equipment that would convert a T1 signal to IP, and automatically switch to the cellular path when the primary T1 failed.

The Engage Communication IP•Tube circuit emulation product line was just the solution the engineers were looking for. They had successfully used the IP•Tube for automatic protection switching of T1 over satellite links, and decided a similar solution would be effective for cellular backup of the critical P25 network. Engage Communication IP•Tube T1-over-IP solutions encapsulate TDM data into IP packets for transmission over IP & Ethernet connections. The IP•Tube uses circuit emulation to transparently transport T1 voice and data, enabling interconnection of T1-based PBX/Voice, public safety radio (LMR) and WAN router equipment over packetbased IP links.

The Link Protector option expands IP•Tube T1-over-IP functionality, adding auto protection switching and eliminating manual intervention in the case of a T1 outage.

Under normal operation, IP•Tube with Link Protector functions in a PassThru (transparent) mode, continuously monitoring the quality of the primary leased T1 connection. In the event of a T1 outage, the IP•Tube immediately detects the failed connection, switches from PassThru mode to T1-over-IP mode, and routes customer T1 traffic over an IP link.

In the public safety radio application, IP•Tube equipment is installed at the radio tower sites and at the regional centers. The primary T1 trunks, linking tower sites back to the regional centers, are monitored for quality on an ongoing basis. If a T1 link drops below customer configured performance levels, the IP•Tube automatically switches tower traffic over the cellular network, restoring T1 connectivity between the tower and the regional center. See Figure 1.

Fig 1 – Engage IP-Tube provides Auto Backup of T1s over Cellular Network 

The IP•Tube automatically switches back to the primary T1 trunk when service is restored. With the IP•Tube again in PassThru mode, the public safety radio traffic is returned to the primary T1 trunk. The primary T1 is monitored for future outages, and the cellular connection can be terminated.

IP•Tube T1 units are available in standalone configurations for deployment at remote tower sites, and in chassis versions for aggregation at regional centers.IP•Tube circuit emulation solutions from Engage Communication offer a number of specialized features which help to ensure a high quality T1 connection over the cellular network:

• Lossless Data Compression reduces Ethernet bandwidth by eliminating idle and redundant data, minimizing cellular bandwidth required;
• Far-End Echo Cancellation suppresses echo in PBX and other Voice applications;
• Assured Delivery Protocol greatly improves on UDP best-effort transport used in TDM-over-Ethernet products by enabling retransmission of dropped packets as well as packet out-of-sequence correction
• Transparent TDM over IP mode ensures all customer traffic types can be carried over the emulated T1 circuit;
• Alternatively, the HDLC-over-IP protocol makes efficient use of cellular bandwidth for WAN router traffic.

The availability of higher capacity/higher reliability cellular networks and IP•Tube T1 Circuit Emulation makes it possible to significantly improve availability for critical public safety communications networks.

Kentucky Counties lower cost of First Responder networks without sacrificing reliability

One of the key elements of an E-911 network is reliable routing of emergency calls to the Public Safety Answering Point (PSAP). This often consists of dedicated analog circuits carried on T1 lines from the Local Exchange Carrier to dispatch centers. In order to reduce monthly telecom costs while retaining the existing dispatch gear, a leading E-911 solutions provider employed Engage Communication equipment to seamlessly transport T1 traffic over cost effective IP networks for a number of Kentucky Counties.

E-911 infrastructure, with life changing consequences, must be extremely reliable. At the same time, government service costs are under intense scrutiny. Fortunately the increased availability of affordable Ethernet / IP networks often make them a viable and cost effective alternative to T1 circuits.

However, many believe the entire E-911 infrastructure must be converted to IP to take advantage of this transport cost savings, including introduction of Voice over IP (VoIP) PSAPs. This would require costly capital expenditures as well as new complexities in training and operations; jeopardizing the Return on Investment (ROI) of replacing T1 with IP circuits.

Fortunately, the Engage IP•Tube product line reliably and cost effectively converts T1 traffic to IP, and then back to T1 again at the other end of the circuit. Thus no changes are required to the PSAP or Local Exchange hand off to take advantage of lower cost IP transport.

With the IP•Tube “Mux” feature, different groups of DS0 voice channels are groomed from a T1 circuit for IP transport to specific PSAPs. This saves on equipment cost and reduces network complexity. The IP•Tube provides numerous other advanced features to ensure high quality transport, including:

• Echo Cancellation to improve voice quality when echo is encountered due to excessive delay in some IP networks;
• Data Compression to reduce Ethernet bandwidth consumed;
• Protection to automatically switch to an alternate IP path if the primary fails;
• Assured Packet Delivery for challenging network environments;
• Stand alone and Chassis configurations.

The IP•Tube product line also converts T3 and serial circuits (RS232, RS530, V.35, etc.) to packets for effective and efficient transport over IP network.

SCADA NERC Redundancy

Case Study

Utility Selects Engage IP•Tube for SCADA Transport to Redundant Data Centers

Power and Utility companies operate SCADA systems to monitor and control power generation & distribution, water treatment and other processes. Advances in SCADA technology and the communication infrastructure, along with natural disaster and security threats – are driving changes in these complex networks. A major Midwestern utility faced multiple issues with their SCADA transport network. The local phone service provider announced the phase-out of legacy telephone services such as 4-Wire Analog and 56 Kbps DDS. At the same time regulatory changes mandated redundant control servers at diverse physical sites to ensure uninterrupted control in the event of a disaster.

• Legacy 4W and DDS telephone services used for SCADA transport were being phased out by the provider
• Single Data Center performing all Control and Monitoring does not meet NERC mandated redundancy

TDM options were available to multiplex 4W modem and DDS channels on to T1 for transport to the control server but the complexity of delivering to redundant data centers over TDM proved daunting. With an extensive fiber/MPLS network available the network planners expanded their search to include IP solutions, including Circuit Emulation to permit use of existing RTU and Communications Front-End (CFE) equipment, while permitting connection to two or more Data Centers. A primary requirement was the ability to support multiple RTU types and SCADA protocols, including DNP at 9600 bps and CONITEL at 1200 bps. A secondary requirement was isolation between the IP network and the RTU equipment for regulatory reasons.

• Engage IP•Tube Serial-over-IP transports Conitel & DNP at multiple clock rates – preserving existing RTUs
• IP/MPLS transport facilitates redundant Data Centers at diverse physical locations – meeting Federal mandates

The network planners selected IP•Tube solutions from Engage Communication with advanced SCADA transport features.IP•Tube Serial Circuit Emulation provides a transparent transport, enabling connection of CONITEL and DNP equipment over the MPLS network. The ability to transport serial SCADA traffic running various protocols and clock rates was a key advantage, as was the ability to configure packet size and buffering to minimize latency across the communication infrastructure.
The initial implementation utilized two control servers at a primary data center, but a second data center is in construction which will house two additional control servers.IP•Tube SCADA features allow any of the four control servers to communicate with a given RTU for Scan and Control. Control signal monitoring ensures the RTU only communicates with the active control server.
Independent connections are provided between RTUs and control centers. This allows all scanning from one control center or a combination. Scanning may be split between control centers for testing, for bringing on a new RTU, and for transition between control centers as required.