Abstract

StreamCore S.A. commissioned The Tolly Group to evaluate its StreamGroomer Module 200 (M200) Flow Regulator along with its StreamGroomer Manager (SGM), a WAN traffic shaping and optimizing system. Tests were conducted to identify the improvement rate of transactions per second (tps) when introducing the StreamGroomer system into a simulated WAN consisting of links with varying degrees of introduced latency. For these tests, The Tolly Group configured a WAN network with varying links, speeds and latencies and measured the baseline performance of the WAN in this uncontrolled environment. Following baseline tests, Tolly engineers measured the transactions across the WAN when the StreamGroomer was added and configured to give priority to interactive transactions. To deliver Quality of Service (QoS), the StreamGroomer builds a set of software “tunnels” between the various endpoints and relays the TCP/IP traffic inside these tunnels. To prioritize, the StreamGroomer system relays the TCP/IP stream of octets into an internal protocol with credit-based flow control. This protocol then creates a session between devices that can be managed by the StreamGroomer Manager software. Tolly engineers measured the StreamGroomer’s capability to stabilize the response time when sending successive files across a simulated WAN.

Summary: Tolly Group Evaluation of StreamCore StreamGroomer Module 200 and StreamGroomer Manager (March 2001)

StreamCore commissioned The Tolly Group to evaluate the performance of its StreamGroomer Module 200 (M200) Flow Regulator and StreamGroomer Manager (SGM) for delivering Quality of Service (QoS) on congested WAN links. The StreamGroomer system builds tunnels between endpoints and regulates traffic using credit-based flow control and Weighted Fair Queuing (WFQ) to prioritize critical applications. Tests simulated real-world WAN conditions with 10 ms and 100 ms latency to measure improvements in transaction throughput and response time.

Results showed significant improvements in performance for SAP R/3 and HTTP traffic when using the StreamGroomer system. In a 2 Mbit/s link with 10 ms latency, SAP R/3 throughput increased from 1.13 to 10.56 transactions per second. HTTP graphical traffic rose from 108 to 140 Kbit/s, while non-critical FTP and SMTP traffic was throttled as designed. Variability in response time dropped dramatically—without StreamGroomer, response time ratios varied by ±35%, while with StreamGroomer they stayed within ±1.2%, proving its ability to stabilize performance across fluctuating WAN conditions.

The StreamGroomer system effectively prioritizes interactive traffic and manages bandwidth proportional to application weights, preventing low-priority streams from starving. It supports a range of application classes (HTTP, FTP, SAP, VoIP, streaming media) and is suitable for deployment at customer premises (CPE) or central offices (COE). Overall, StreamCore’s StreamGroomer proved to be a highly effective WAN traffic shaping and optimization solution, delivering measurable performance improvements for latency-sensitive applications.