How we did it

Also: Do more with your bandwidth

The main office and branch office networks were comprised of Cisco Catalyst 2924XL and 5500 switches and route switch modules. Each network consisted of several Windows 98, NT, 2000 and Linux workstations. We also had a Win 2000 server located on the main office network. Each office also had a voice-over-IP phone, and the main office housed the call manager, which serves to connect and manage calls.

We used Spirent Communications' SmartBits 2000 cards for network throughput and packet loss testing and NetIQ's Chariot for generating application-specific traffic.

For throughput and packet loss, we tested the QosWorks 10000 with two ML-7710 Fast Ethernet cards in a SmartBits 2000 chassis using SmartWindow software. The ML-7710 cards were configured for full-duplex, 100M-bit/sec operation, and used line-rate Ethernet frames in sizes between 64 and 1518 bytes to determine if performance was a function of frame size or rate.

For our Chariot testing, each workstation and server ran NetIQ's endpoint software to let Chariot generate and receive traffic. We used Chariot to create several streams of competing HTTP, FTP and Simple Mail Transfer Protocol traffic that were sent from endpoint to endpoint across the WAN link. We then created a policy for each type of traffic and monitored the streams to see how closely they matched the applied policy. During testing, we varied the bandwidth characteristics of each policy to better understand how QosWorks 10000 enforced these policies.

We also placed voice-over-IP calls across the congested link and tried to transfer files from a Win 2000 file server, with and without bandwidth policies, to add further realism to the tests.

Griffin and Goddard are network engineers for Network Services at the University of Florida. They can be reached at cgriffin@ufl.edu and ggoddard@ufl.edu.

Do more with your bandwidth
Sitara Networks' QosWorks 10000 provides powerful quality-of-service features.

Sitara brings QoS to branch offices
QoSWorks is designed for branch and remote office environments where WAN speeds top out at T-1/E-1.
Network World, 02/14/00.