Bandwidth Management Face-off: Packeteer
|
|||
 | |||
|
Packeteer's TCP rate control technology applies a simple principle to the challenge of managing bandwidth: Control network traffic by specifying the rate at which data is transmitted rather than received.
TCP rate control has four clear advantages over traffic queuing. First, by exerting control at the ultimate packet source - the transmitter - rather than simply queuing on the receiver end, TCP rate control proactively prevents congestion from causing delays on the access link. The result is greater network efficiency and reduced packet retransmission. Queuing-based systems use packet delay or loss to control bandwidth indirectly, wasting available bandwidth and degrading quality.
Second, TCP rate control manages traffic traveling inbound from the slower WAN onto the faster LAN. Queuing systems have a tough time controlling such inbound traffic because queuing only works where queues form, such as where a LAN meets a slower WAN link. Class-based queuing (CBQ) must be used on both ends of an access link to control traffic in both directions. TCP rate control manages bidirectional traffic from one point in the network.
Third, TCP rate control can operate on a per-flow as well as a per-class basis, enabling precise application quality of service (QoS). CBQ operates only on an aggregate, per-class basis. Per-flow traffic management enables precise bit-per-second control, as opposed to the relatively coarse control of per-class or aggregate approaches. The ability to classify traffic by application flow - at the content or end-user level - is critical for true policy-based networking.
Finally, TCP rate control is an open, standards-based technology supported by recent work in the academic community. Furthermore, it presages work coming from the Internet Engineering Task Force's Diff-Serv working group on TCP explicit congestion notification. See specific article references at Packeteer's Web site.
An effective bandwidth management product must manage a rich mix of IP and legacy traffic, particularly on the enterprise network. With Packeteer's technology, non-TCP traffic can be explicitly managed. Controlling this mix, however, requires mechanisms such as deadline scheduling and latency control in addition to TCP rate control. Packeteer's products employ multiple mechanisms to manage the variety of traffic types found on today's multiservice networks.
Rich traffic classification, TCP rate control, deadline scheduling, latency management and support for evolving QoS and TCP/IP standards: These are the vital ingredients for effective bandwidth management. Without them, you cannot fit bandwidth to your company's needs or enable true application QoS.
Quillin is vice president of marketing for Packeteer, Inc., a Cupertino, Calif.-based maker of bandwidth management products. He can be reached at bobq@packeteer.com.
Related Links
TCP Rate control information page
from Packeteer
