Guard fine-tunes ATM video
Guard fine-tunes ATM video
Distance-learning project is in place but is not quite ready for prime time
Distance-learning classrooms have
By Bill Murray
Although video streaming over an asynchronous transfer mode network poses a particular challenge, Army National Guard officials report that their Distributed Training Project is moving forward.
'It ain't magic, and sometimes it ain't pretty,' said Lt. Col. Dennis Donovan, program manager for the project, which is the first known federal ATM network to have points of presence in all 54 states and territories.
Guard officials have deployed more than 120 distance-learning classrooms and plan to install 80 more by 2000, he said.
Citizen soldiers generally train two days a month.
'It works at the lab, but when you put it in the field, you learn a lot. We're still tweaking it,' Donovan said when asked about the traffic over the T3 backbone, which is being supplied by subcontractor MCI WorldCom Inc.
'We're taking hits on the video,' said Vernon Fadeley, a telecommunications manager at Electronic Data Systems Corp. 'Switch vendors and carriers have learned on this.'
'We're at the early stages' of video streaming, Donovan said. 'It will take some time to work out the bugs.'
The ATM network gives the Guard live video, videoconferencing, video on demand, voice and data in 54 states and territories.
He compared the state of video streaming with early television broadcasts, when interruptions in service were common.
The Guard has Distributed Training Project contracts with EDS for classroom installation, network design and integration; Booz, Allen and Hamilton Inc. of McLean, Va., for program design and management; and Richard S. Carson & Associates Inc. of Bethesda, Md., for program support and oversight.
Guard officials are learning about shaping digital signal Level 3 (DS-3) over networks over notes of typology and integrating data, video and voice streams, Donovan said. DS-3 is a framing specification used for transmitting digital signals at 44.7 Mbps on a T3 connection.
The Distributed Training Project began in 1996 with demonstration classrooms in four states, including West Virginia, which has the most operational sites in the Guard, Donovan said. The Guard could complete the Distributed Training Project by 2007 if funding comes through, he said.
With communications networks, it is a challenge to prioritize voice calls, video calls and data calls, said Polo Morales, EDS' Army technical director.
Users will not tolerate any loss on voice calls; that is why those exchanges have to come first, he said, but those priorities could change. Seven regional hubs on the network tie in with state area command headquarters (STARCs)'usually located in state capitals. The 54 STARCs are linked on a T3 backbone.Have class, will travel
In collaboration with the Army, Guard officials want to build 600 distance-learning classrooms to ensure that few active duty or reserve soldiers have to drive more than an hour to arrive at an interactive distance-learning center, Donovan said.
The Guard has 367,000 citizen soldiers and 3,200 armories.
Recently, Guard officials have learned how to use routers between Cisco Systems Inc. switches and ForeRunner ASX-200BX ATM backbone switches from Fore Systems Inc. of Pittsburgh, Donovan said. The ForeRunner ASX-200BX switch has redundant design with no single point of failure.
Hubs from 3Com Corp. of Santa Clara, Calif., give the Guard voice-over-ATM capabilities, said Andy Carpenter, an EDS telecommunications engineer. '3Com is one of the few vendors that had it,' he said. The Guard is also using switches from Bay Networks Inc. of Santa Clara.
ATM video networking equipment from FVC.com Inc. of Santa Clara gives the Guard videoconferencing, video on demand and live video.
FVC.com's V-Caster, V-Cache, Access NGI and V-Gate products are installed at each hub, and the Guard has 25-Mbps ATM connections to desktop PCs through Access NGI.
The service also uses PC compression and decompression boards for audio, data and video from Zydacron Inc. of Manchester, N.H. Zydacron's OnWAN H.320 are ISA and PCI boards that can run on the Guard's Compaq Deskpros under Microsoft Windows NT Workstation 4.0.
Users can make point-to-point and point-to-multipoint video conference calls at 1.15 Mbps.Hidden message
Netstream 3 MPEG-2 decoders from Sigma Designs Inc. of Milpitas, Calif., deliver streaming video and audio across the Guard's WAN to each PC in 70 classrooms.
To ease network strain, the Guard is distributing large courseware over the network to regional hubs in California and Virginia during nonpeak periods, Donovan said. The Guard can upgrade and scale the network as usage increases. The initial migration goes from T1 to T3 and then on to OC-3 and finally to OC-12.
'There will be no need to do a forklift upgrade of entire switches or sets of switches. We can upgrade modules,' EDS' Morales said.
States manage the Guard facilities, and they can rent network access to federal agencies and private-sector users when the Guard is not using the facilities.