Start-up Orbital Data Corp. is launching gear that it says boosts throughput on WAN connections 10 times or more by overcoming bottlenecks caused by the limitations of TCP.
Called Orbital 5500, the appliance is sold in pairs with one at each end of a wide-area link, where they optimize TCP sessions so transmissions fill the available pipe rather than sending at the slower speeds that TCP normally dictates.
TCP requires an acknowledgment of each packet, and if that acknowledgment is slow or fails to come, the sending machine throttles back its transmission rate, assuming the link is congested, even if it’s not, the company says. Orbital says this can result in WAN connections running at only 20 per cent of capacity because of packet loss across the link.
To eliminate this, the company uses a feedback mechanism between its devices so traffic is sent at the speed of the connection. This is done using Orbital’s own flow-, congestion- and retransmission-control algorithms and buffers in the boxes. When traffic is sent across a WAN, it is sent using standard TCP. Orbital Data calls its technology Total Transport.
Competition Competitor Peribit Networks Inc.’s WAN gear adjusts TCP receive-window size to maximize throughput across WAN connections. Peribit gear also compresses traffic. Start-up Aspera sells software that sends WAN traffic using a proprietary transport mechanism other than TCP. Riverbed Technology Inc. spoofs protocols to reduce the number of transactions necessary to complete a WAN transfer, thereby reducing the total number of packets crossing the connection.
Using Orbital 5500 boosted throughput for film production company Nice Shoes from 300Kbps to 4.5Mbps — 15 times the throughput, says John DiMaggio, the New York firm’s director of new media services. In addition to speeding up the traffic, the Orbital 5500 devices can reserve bandwidth for traffic other than the large video files the company sends, DiMaggio says. To accomplish this, he has set the devices to max out at 5Mbps, so 1Mbps of bandwidth will be left even when sending video files.
One drawback is that the system requires a box at both ends, he notes, and if a business partner doesn’t own one, Nice Shoes has to put up with slower speeds. The company has two Orbital Data boxes, and for big jobs, sends the second one to the partner. The devices are placed between the LAN and the WAN, and if they fail, traffic passes through as if they weren’t there.
Orbital 5500 is managed via a Web interface on each device. Pricing ranges from US$12,000 for T-1 throughput to $50,000 for 200Mbps throughput.
The company was founded in June 2002 and is funded by $15 million from Sevin Rosen Funds and Redpoint Ventures. Its CEO, Richard Pierce, is the former COO of Inktomi.
