Microsoft is finally starting to get some support from network hardware vendors for the quality-of-service (QoS) interfaces it has built into Windows 2000.
The interfaces will allow applications to request a certain level of bandwidth from the network, therefore shaping traffic and giving more important applications the service they need to run efficiently. However, critics say that QoS controlled by applications is a Pandora`s box.
Packeteer, award-winning developers of a family of application-level traffic management products under the name PacketShaper, recently announced it is adding support for the QoS signaling API that is available in Win 2000.
The hardware is the first to support the Generic QoS (GQoS) API that Microsoft developed as part of its new operating system. The API is based on two Internet Engineering Task Force standards. The API uses Resource Reservation Protocol, which allows applications to request an allotment of bandwidth from a policy server. GQoS-enabled applications use that protocol to communicate with PacketShaper.
In addition, the applications use Differentiated Services to mark packets with policy data.
QoS mechanisms historically have been confined to hardware such as routers and policy servers. Microsoft`s unique approach to QoS lets applications tell the network that users are requesting bandwidth and the amount they need.
However, there are limitations to application-based QoS requests. They lack traffic management features needed to determine if a request can actually be accommodated.
Critics say applications that request bandwidth know nothing about network traffic flow and, therefore, may request more bandwidth than is available. The situation could leave QoS policies in shambles as the network tries to fill bandwidth requests from applications.
"The good news is that applications know what they need from the network, but the bad news is there needs to be a traffic monitor," says Mike Howard, principal analyst and founder of Infonetics Research in San Jose. "The traffic monitor problem has to be solved."
Microsoft officials acknowledge the issue and say GQoS compliments traffic monitoring by offering a smart host that can mark traffic, identify users and make applications aware of the network.
"I would not turn my network QoS over to my applications," says John McConnell, president of McConnell and Associates in Boulder, Colo. "You should keep policy decisions where you can control them, and that`s not at the desktop."
PacketShaper will provide the policy decisions for applications, sitting in front of network switches and enforcing policies. The hardware includes the intelligence to determine if the network has the bandwidth to fill requests.
PacketShaper has three critical features that support GQoS-enabled applications. First, it can analyze network traffic to determine who is using what bandwidth and when. I t also can control traffic by assigning policies, monitoring those policies and warning when they are ineffective.
Packeteer is developing Packeteer Application QoS Enabled Traffic Signaling (PAQETS) to support Win 2000 GQoS and user authentication. Packeteer plans to add PAQETS support to PacketShaper and a similar product called AppVantage, which is intended for application service providers.
Packeteer says application-level signaling could be an advantage for IPSecurity traffic because PacketShaper will never have to look inside encrypted packets to determine what kind of QoS policies to assign. The application will provide that data.
With Packeteer on board, Microsoft must now begin to solve the other side of the equation - applications. Currently only Microsoft`s NetMeeting and NetShow support GQoS, but SAP in the next version of its R/3 applications will support the API.
Says IT Wise Marketing & Financial Director, Nico Malherbe: "PacketShaper with support for Win 2000 GQoS is expected to ship in the fourth quarter of this year. Pricing has not been set."
Share
