Military Embedded Systems

Case study: EFV keeps pace with Ethernet to actualize net-centric warfare


August 14, 2009

Mike Southworth


Case study: EFV keeps pace with Ethernet to actualize net-centric warfare

The success of net-centric warfare is dependent on fast, secure communications technology - specifically Ethernet. To meet the military's demands for Ethernet-enabled vehicles, Ethernet switches and routers need to be increasingly rugged and capable of meeting future network requirements. A case study of the USMC's Expeditionary Fighting Vehicle (EFV) with its Tactical Switch Router (TSR) exemplifies this trend.

The advent of net-centric warfare has spurred the rapid development of networking technology as the military's success must rely on the accuracy, power, and speed of communication technology. To ensure the safety of soldiers and mission success, net-centric operations depend on information exchange platforms that support mature and well-tested protocols, offer data in near real time, and provide advanced roadmaps for future performance. Currently the primary communications technology to meet these requirements is Ethernet.

Although not new on the military scene, this venerable COTS LAN technology is replacing a myriad of other backplane choices. Traditional vehicle data buses such as MIL-STD-1553, CANbus, and RS-232 continue to have an important role in mission-critical military applications. However, due to their limited bandwidth and the growing priority to gather and synthesize information as quickly as possible for situational awareness, Ethernet is becoming the preferred enabler for situational awareness in many battlefield platforms.

Despite the desire for high speed and performance, not every application receives tangible benefits from the faster pipe offered by GbE or 10 GbE. In fact, Fast Ethernet often meets current network requirements, since actual Wide Area Network (WAN) backhaul speeds are often slower than 100 Mbps in the field. This is because the speed of inter-vehicle communications can be constrained by the wireless connection, which becomes the bottleneck for speed and performance. However, for intra-vehicle communications not limited by the bottlenecks of a WAN connection, onboard computing devices certainly benefit from 1 Gbps or faster connectivity.

To help the military meet its current need for Ethernet-enabled vehicles and to anticipate future demands, there is increasing pressure on defense contractors to provide rugged Ethernet switches and routers that meet the requirements of Space, Weight, Power, and Performance – Cooling and Cost (SWaP2-C2). Additionally, these network switches and routers must endure the harshest environments to enhance situational awareness in unmanned aircraft, tactical ground vehicles, and maritime assets, where standard commercial-grade equipment cannot survive. An excellent example of this is the Tactical Switch Router (TSR) found in the USMC's Expeditionary Fighting Vehicle (EFV), as the following case study illustrates.

Expeditionary Fighting Vehicle – Net-centric Ethernet at work

One of the many significant deployments of Ethernet in the military is in the Expeditionary Fighting Vehicle – the Marine Corps' highest-priority ground combat modernization program. Designed and developed by prime contractor General Dynamics, the EFV is an armored amphibious vehicle capable of seamlessly transporting Marines from Naval ships located beyond the visual horizon to inland objectives (see article lead-in photo above). The new vehicle is a self-deploying, high-water-speed, armored, tracked vehicle to provide essential Command, Control, Communications, Computers, and Intelligence (C4I) functions for embarked personnel and other EFV units1.

General Dynamics initially selected Fast Ethernet as the main inter-vehicle network protocol for linking various IP-enabled computing and communications devices in the EFV. General Dynamics needed a rugged router that wasn't yet commercially available to sustain its networking requirements. General Dynamics contracted with Parvus Corporation to develop the Tactical Switch Router – which enables the deployment of communications-on-the-move and information-sharing capabilities, supporting the Marine Corps' net-centric operations initiatives.

The EFV includes multiple connections for a network backhaul over satellite or line-of-sight wireless technologies, depending on the vehicle variant, to fulfill its mission. Empowering situational awareness, the TSR subsystem connects to a variety of IP-enabled computing workstations and Radio Frequency (RF) device LRUs to support an Ethernet-based intra- and inter-vehicle network. Remote users can exchange voice, video, and data communications with a central site and securely access resources in real time.

Developing the Tactical Switch Router

The miniaturization of components allows more functionality to be packaged into communications technology – a key requirement of the USMC for the TSR. Parvus met this challenge by combining the router and Ethernet switch in one stand-alone Line Replaceable Unit (LRU). This engineering development simplified installation and maintenance for the USMC, which ultimately saves time and reduces costs.

By basing the TSR router on Parvus' COTS DuraMAR Mobile IP router product, the EFV benefited from a small form factor rugged router subsystem that integrated Cisco Systems' Rugged 3200 Series Integrated Services Router (ISR) and Internetwork Operating System (IOS) with an isolated military-grade DC/DC converter in a rugged chassis with MIL-C-38999 interfaces. Capable of delivering secure data, voice, and video communications to stationary and mobile network nodes across wired and wireless networks, this proven IP networking solution includes Cisco's stackable embedded PC/104-Plus modules, the 3251 Mobile Access Router Card (MARC), 3201 Fast Ethernet Switch Mobile Interface Card (FESMIC), and 3201 Serial Mobile Interface Card (SMIC) (see Figure 1).


Figure 1: TSR/DuraMAR 3230 system diagram depicting Cisco 3200 router and serial and Ethernet switch cards interfacing with two Parvus COM-1268 GbE switches.




The pervasiveness of Cisco technology and its IOS software in the government arena was a critical factor for specifying this routing technology in the TSR. According to industry reports, Cisco has at least a 70 percent market share in the U.S. government's IP network infrastructure. By including network management software that the U.S. Marine Corps has been trained to operate, the learning curve to operate the TSR would be diminished and improve the EFV's time to deployment.

The 3200 Series is one of the few rugged routers that passed the Common Criteria Evaluation and Validation Scheme (CCEVS) EAL 3 assurance program sponsored by the National Institute of Standards and Technology (NIST) and the National Security Agency (NSA). Further, it is one of the first to support Internet Protocol (IP) mobility per the Internet Engineering Task Force's (IETF's) Mobile IP Standard RFC 2002. With Mobile IP, mobile device users can move from one network to another while maintaining a permanent IP address.

Cisco IOS software also afforded the USMC advanced capabilities for network security, manageability, and scalability. Some of the integrated network security features include authorization and authentication, stateful firewall, intrusion detection, and Triple Digital Encryption Standard (3DES) or Advanced Encryption Standard (AES) encryption for VPNs. Remote management capabilities give network managers visibility into and control over the remote network, including devices connected to the router. Powerful debug and troubleshooting commands allow network managers to quickly isolate network problems and securely make changes to network configurations.

Since the EFV is an amphibious vehicle armed with a 40 mm MK44 cannon and 7.62 mm machine gun, the TSR subsystem would be exposed to gunfire shock, as well as underwater and tracked vehicle operation with operational shock levels in excess of 20 gs. The rugged 3200 ISR was specifically designed for establishing a highly secure IP network with remote devices in a moving or stationary vehicle in harsh conditions. It also underwent environmental testing to MIL-STD-810F and SAE J1211/J1455 parameters.

Advancing the EFV

As the DoD moves toward upgrading to Internet Protocol version 6 (IPv6) this year, support of IPv6 has become a core requirement for network-centric warfare. Again, the 3200 router was the answer as its IOS management software is IPv6 compliant – further validating the necessity of the 3200 router in the EFV.

In keeping pace with the initiative to "future proof" the EFV, the latest revision of the TSR integrates two PC/104-Plus GbE switch cards into a new chassis to provide a total of 17 Ethernet ports – more than triple the number of available ports on the original TSR configuration or normally available from Cisco's standard product. By integrating the 3200 Series' mobile access router technology with PC/104-Plus GbE switch cards, the TSR offers expanded LAN port count and consolidated switch and router functions into a single hardened subsystem designed to MIL-STD-810F and MIL-STD-461E environmental conditions. Sealed MIL-C-38999 connectors bring out an IOS-managed 10/100 WAN port, three IOS-managed 10/100 switch ports, and 13 10/100/1000 GbE switch ports, as well as 2 multiprotocol serial ports and an RS-232 management console port. These additions supply the EFV with enough capacity to meet future networking demands.

Since receiving the original TSR development contract in 2007, Parvus has also received additional contracts for reliability improvements and functional upgrades to ensure system performance. Among these improvements were upgrades in ruggedness and thermal design. Flex cabling was instituted to improve shock and vibration and provide solid reliability. Conduction cooling advancements were also instituted, such as clamshell heat sinks for each printed circuit card assembly and finned extruded chassis to reduce thermal issues and improve reliability. The latest version of the TSR subsystem helped shape other rugged COTS router product offerings (Figure 2).


Figure 2: The EFV program influenced the development of the COTS DuraMAR 3230 subsystem, which has only minor mechanical differences from the TSR and will become a standardized version of the TSR for generalized use by the armed forces.




Future of Ethernet in net-centric warfare

As the military's growing quantity of complex, mission-critical applications needs increasing ruggedness, security, and bandwidth, GbE is ensured a productive future in net-centric operations. However, the successful implementation of 10 Gigabit speeds depends on the development of switches and routers to accommodate this technology. As witnessed from the design and deployment of EFV and the TSR, government contractors and suppliers are well primed to help the military meet its net-centric objectives.

Mike Southworth serves as director of marketing for Parvus, a manufacturer of rugged COTS computing and IP networking subsystems for military and aerospace applications. In his role at Parvus, Mike oversees the product management and marketing communications programs. Mike holds an MBA from the University of Utah and a B.A. in Public Relations from Brigham Young University. He can be contacted at [email protected].

Parvus Corporation 801-433-6331

1 At the time of writing this article, Secretary of Defense Robert Gates had proposed budget reductions for Future Combat Systems vehicles. Although the EFV has come under question, it remains unscathed for now.


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