The IP shift ... slow and steady

There are still a lot of legacy networks out there. Frame relay, asynchronous transfer mode, you name it. Most work fine, but the lure of Internet Protocol-based networks'of economical, standards-based infrastructures'is undeniable. As a result, agencies continue to migrate to IP networks for even their most mission-critical systems.The National Law Enforcement Telecommunications System network, for one, recently moved from a proprietary protocol to IP, giving state, local and federal officers improved services and more secure access to law enforcement data. The cutover of the final endpoint last February marked the end of a nine-year transition that brought the international system into compliance with FBI security requirements and enabled new features such as use of Extensible Markup Language and Web services.'The end result is that even though data is coming from another state, it looks like what the officer at the endpoint is used to,' said NLETS operations director Frank Minice.The new network also is faster and more robust. In the event that the main operations center in Arizona goes offline, a back-up center in Idaho can be brought online in less than 30 minutes.Flexibility to grow is a critical part of IP-based networks. NLETS provides interstate communications among 18,000 state and local law enforcement agencies, as well as federal law enforcement organizations. It also links with Canadian criminal records systems. The network handles more than 40 million messages a month, including Amber Alerts for missing children and security alerts to local officials from the Homeland Security Department.'We have 100-and-some links, and we're reaching out to 500,000 end devices,' Minice said.NLETS is, as it has been for decades, housed in Phoenix at the Arizona Highway Patrol headquarters, which was one of two organizations that offered to host the system in the 1960s.'Historically, we have used proprietary protocols in NLETS,' Minice said. At one point it was a bisynchronous protocol that provided half-duplex communications over point-to-point lines leased from AT&T Corp.Minice said the proprietary network was extremely reliable because it required that each bit be acknowledged before the next was sent. But this added to network overhead and slowed the system. Also, it handled only text. 'We knew we needed to move forward. ... In our last mainframe upgrade that we did in 1996, we incorporated a proprietary TCP/IP and started moving our users to IP,' Minice said.A key element in the transition was selecting a hardware platform. Standardizing on equipment from Cisco Systems Inc. helped simplify the process.Many administrators at state and federal agencies were already familiar with Cisco equipment, easing installation and maintenance. NLETS administrators also can perform remote troubleshooting, an important consideration because of manpower constraints; the core NLETS team consists of only 14 people.By 2003, NLETS was running IP over a frame relay network from AT&T. Then it was a matter of cutting over the systems' various endpoints to IP. For a while, many locations ran IP and the legacy protocols.Running both protocols at many sites during the transition gave users a chance to fully test the system before making the move to IP.'In some cases, it was difficult to get them to make the move,' Minice said. Older mainframe systems required some coding changes, and for all of its shortcomings, the bisynchronous system worked and was reliable. 'The long-term benefits of switching aren't immediately recognized by everybody.'The move to IP was spurred in part by an FBI mandate that public safety agencies encrypt data in transmission by 2005. 'We wouldn't have been able to do that on the bisynchronous network,' Minice said.NLETS encrypts IP traffic in virtual private network tunnels using the Triple Data Encryption Standard algorithm. It is in the process of moving to the Advanced Data Encryption Standard.Although the transition was transparent to end users'cops on the street'the improved speed and functionality of the new iteration of NLETS has been noticeable.'Being able to implement the system was a big asset for us,' said officer Scott McEuen of the Arizona Department of Public Safety. Each patrol car has a notebook computer locked into a docking station. 'Here in Phoenix we have a high volume of radio traffic. Lots of times you can't get across. This helps hold down the radio traffic because you can use the computer to get the information.'In the end, it was peer pressure that helped spur the final transitions.'Cops talk to each other,' Minice said. 'These users ended up forcing the move on their tech people. ... The incentives were the new services we offered. If they didn't move to the new technology, they would be missing out.'NLETS is still a data network, but with the move to IP, that could change.The operations center already is using voice over IP with Cisco CallManager and IP telephones. An IP network could let police on the street make free officer-to-officer VOIP calls. 'There will also be videoconferencing,' said Cisco's Morgan Wright. 'We haven't even begun to tap into the capability of IP.'