Voice of Experience: War Dialers

By Baselinemag  |  Posted 2005-10-01 Print this article Print

David M. Mihelcic, chief technology officer of the Defense Information Systems Agency, says Internet-based phone networks need more care and feeding than traditional phone systems.

David M. Mihelcic
Defense Information Systems Agency
Arlington, Va.

MANAGER'S PROFILE: In charge of technical strategy for the agency's telecommunications and information-technology programs, which support the U.S. Department of Defense. With 7,173 employees, the Defense Information Systems Agency has a budget of $6 billion for 2005.

HIS PROJECT: The U.S. military has launched just a few Internet Protocol telephony projects to date. The main holdup, Mihelcic says, was that none of the vendors provided a way to automatically interrupt a call if a more urgent one came in—if, say, the president needed to reach a commander immediately. Cisco Systems now offers this feature in its CallManager software, and the agency has put in about 1,000 Cisco phones on its unclassified data network on a trial basis at its Arlington headquarters.

TOP SECRET: The agency also uses Cisco IP telephony gear over its encrypted network for classified information. That lets field units deploy communications with less equipment, according to Mihelcic, since they don't need to bring bulky circuit-based phone switches with them.

THE TOOL SET: A staff of 200 manages the agency's global IP network from data centers in the U.S., Europe, the Pacific Rim and southwest Asia. The team uses software from Concord Communications (now part of Computer Associates) to monitor packet loss and latency. The agency also uses Brix Networks' test equipment to measure voice-over-IP quality.

FUZZY PATHS: Compared with traditional voice networks, managing IP telephony networks is "still not an exact science," Mihelcic says. With circuit-switched networks, he points out, a phone either can establish the circuit or it can't. In an IP network, however, a device can almost always establish a connection, but the quality of the connection can fluctuate.

ON THE EDGE: In the high-speed core of the agency's data network, which runs at a minimum of 40 billion bits per second, congestion is virtually nil. But voice traffic can hit turbulence at the edge of the network, because lower-speed connections are more prone to interference. The only way to identify such problems today is via constant monitoring by operations staff. But the long-term goal, Mihelcic says, is to make the process more automated: "Eventually, we want to have fewer hands involved in running the voice network."


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