Packeteer Delivers SNA QoS over IP

In a move to ensure the high-level performance of mission-critical host and e-business applications over enterprise Wide Area Networks (WANs) and the Internet, Packeteer Inc. (Cupertino, Calif.) has enhanced its PacketShaper bandwidth management solution with Web-enabled host access support.

The demand for Web-enabled host access indicates companies are evolving traditional AS/400 and mainframe green-screen access to a Web-type interface, according to Todd Krautkremer, VP of marketing for Packeteer. "The problem that occurs when you take that step away from any kind of green-screen emulation toward a browser-based access medium is that you've gone to an all-IP network, and as a result you have lost all the application-level class of service features that SNA provided," he says. "What we in essence do is deliver SNA-like class of service to these all-IP network models, where people are using browser-based access to the [back-end server]."

Those who will find the greatest value in Packeteer's SNA-over-IP technology are IT shops previously wary about sending time-sensitive, transaction-based information over IP networks. In addition to offering greater reliability, Packeteer is also counting on the availability of SNA Quality of Service (QoS) over IP to reduce the need to maintain separate SNA and IP networks.

PacketShaper with Web-enabled host access support is designed to deliver a number of SNA's more popular QoS features, including session-level class-of-service, traffic pacing and response-time monitoring. The solution can now discover and classify several different Web-enabled host access traffic types, such as TN5250, TN5250p (print), TN3270, TN3287 (print) and 3270/5250-to-HTML emulation, as well as OpenConnect's JCP protocol. In addition, Packeteer works with application vendors such as Hummingbird Communications Ltd. (North York, Ontario), Attachmate Corp. (Bellevue, Wash.), OpenConnect Systems Inc. (Dallas) and Esker US Inc. (Stillwater, Okla.) to identify and optimize their offerings across WANs.

Using the PacketShaper's core technology--its capability to discover and classify all the traffic that runs from, for example, a remote branch into a data center that has an AS/400--the user can discover not only the TN5250 and browser-based access to the AS/400, but also all other traffic competing for bandwidth with those sections, according to Krautkremer. "That would allow the manager to use our product to analyze who's using what bandwidth and to understand how to begin to implement policies that can control this utilization and ensure that the interactive, former SNA users are getting the type of response time and throughput necessary for their particular applications."

PacketShaper's enhancements arrive on the scene at a time when most corporations are migrating to TCP/IP intranets, according to Donald Czubek, president of Gen2 Ventures, a Saratoga, Calif.-based consultancy specializing in enterprise-strength TCP/IP and SNA networking. Based upon his experience with APPN and SNA migration to IP, Czubek confirms that the greatest challenge to IT managers is maintaining control over end users' QoS.

"It's very important for enterprises to maintain an SNA level of QoS for a number of reasons," Czubek says. SNA users being migrated to TCP/IP have very high expectations with regard to performance. "Traditionally, they've been using SNA and getting sub-second response time fairly consistently." User productivity is another reason why high QoS must be maintained, particularly when those users are involved in an interactive application and their productivity depends upon response time.

A third reason to maintain high-level QoS is customer satisfaction. Many users of IBM interactive terminals are involved in customer service-type applications, Czubek points out. "They may have a customer on the phone inquiring about their account. In order for an enterprise to make the move to TCP/IP, it has to be able to guarantee the QoS."

Packeteer is not the only vendor in the networking solutions space to offer solutions for maintaining QoS; a number of networking hardware vendors have made this a priority as well. "What's unique about Packeteer is PacketShaper's capability to provide an automatic analysis of the traffic streams and specifically identify, for example, 5250 sessions," Czubek says. Whereas other QoS products on the marketplace work by examining IP addresses and port numbers--which is fine for generic traffic stream identification--PacketShaper is designed to penetrate deeper into the packet, sorting out ordinary Telnet from 5250 and distinguishing between printers and display stations.

This capacity for identification provides for better prioritization of resources. The key difference between Packeteer's prioritization method and the method of most router vendors is that PacketShaper proactively prevents congestion from occurring, thus preventing packet loss, according to Czubek. "Prioritization is generally a reactive technique and doesn't begin to work until congestion occurs, and then it attempts to make the best of a bad situation."

About 70 percent of Packeteer's customer base use one or more members of the IBM server family, including AS/400, RS/6000, S/390 and Netfinity. Overall, about 25 percent of Packeteer's customer base use AS/400 technology. Krautkremer says he expects the number of Packeteer's AS/400 user base to change dramatically with this announcement of Web-enabled host access.