FRAMINGHAM (03/27/2000) - We installed the server cards on an NEC Corp.
Direction SPB 450-MHz Pentium II server with 128M bytes of RAM, running Windows NT Server 4.0 with Service Pack 4 applied. Our FTP server was a Dell Computer Corp. Dimension XPS Pro 200n with a 200-MHz Pentium Pro processor and 64M bytes of RAM running Windows NT Server 4.0 with Service Pack 4 and Internet Information Server 4.0. The FTP server and the remote access server (RAS) had a 100M-bps Ethernet connection to a 3Com SuperStack II Dual Speed Hub 500.
Our clients were 23 Dell OptiPlex PCs with 166-MHz Pentium processors and 32M bytes of RAM. We connected each PC via a serial port to a 33.6K-bps modem housed in a 3Com MP/16 V.34 Total Control modem pool. We used Windows 95Os dial-up networking utility and PPP to dial in to our on-site Lucent Definity G3I PBX. From the PBX to the RAS servers, we used an ISDN Primary Rate Interface line.
We created a test script that opened a DOS window on each client, loaded the FTP program supplied with Windows 95 and typed the commands needed to transfer five, 32K-byte test files to and from a test server. We measured throughput at each client using the statistics provided in the FTP program, which ignores the transmission of FTP commands in its calculations.
During testing, all remote access servers were configured to authenticate users using Challenge Handshake Authentication Protocol and to autoassign IP addresses. All clients used the same user name and password.
First, 12 simultaneous dial-in connections were established. Throughput testing was achieved via simultaneous FTP transfers, starting with a single client and increasing the size of the group in increments of one up to 12 clients. We ran each test three times and averaged the results. If calls were dropped, we reran the test until we completed three successful passes.
Download throughput was lower than upload because the remote access server took on the extra burden of performing file compression. During uploads, files were compressed by the client. To test performance, we downloaded and uploaded files of various sizes and types via our FTP server and measured throughput for 23 simultaneous RAS clients using a PRI connection.
We also evaluated the products for ease of use, manageability, scalability, installation and documentation.