LapLink Enterprise Exchange Accelerator

Speed up your dial-up email access

Traveling Software's LapLink Enterprise Exchange Accelerator is a client/server system that significantly speeds the transfer of messages to and from a user's computer over a remote connection, thus reducing dial-up charges. Exchange Accelerator provides filtering options to block automatic downloading of attachments larger than a size users specify. The product's server software installs on a system that resides on the same network as the Exchange server. Exchange Accelerator executes client requests for mail services on behalf of the client. Message and attachment transfer is fast because Exchange Accelerator uses advanced compression, large packet sizes, and a proprietary transport protocol that works over TCP/IP or IPX/SPX. Exchange server logon and authentication is fast because the network traffic between the Exchange Accelerator server and the Exchange server travels at local network speeds. Efficient authentication passes from the client over a dial-up or VPN connection to the Exchange Accelerator server. Organizations with a large remote-user base will appreciate Exchange Accelerator's Load Balancer service, which provides load balancing between multiple Exchange Accelerator computers. You install Load Balancer on a separate computer dedicated to load balancing at the time you install Exchange Accelerator.

Server Installation
Exchange Accelerator's wizard-based server software installation is fast and uncomplicated. You need to know only which email connectors are running on your Exchange server. For my installation, I checked the Internet Mail Service box on the Advanced tab of the LapLink Enterprise E-mail Accelerator Server Properties page, as Screen 1 shows. You can select additional installation options on the server properties page. For example, you can select options for activity logging to the Windows NT Application Event Log (AEL) on the Logging tab. Click the Advanced tab to install additional Exchange connectors or to change Exchange Accelerator's Service Account.

Client Installation
Systems administrators can distribute Exchange Accelerator client software to remote clients in several ways. Emailing a 4.5MB self-extracting installation program to remote users is perhaps the easiest option. You can also create a set of four 3.5" client installation disks or a CD-ROM for delivery to remote workers. For systems on the local network, you can install the client from a shared directory on the Exchange Accelerator server. The installation process is user-friendly—the software installs without your needing to do anything more than swap disks. Users must reboot their remote system for the client installation process to complete. After the reboot, the installation program asks users to select the email profiles that they want to configure for Exchange Accelerator, then the program configures itself to work with the Exchange server mailboxes in the selected profiles.

Getting the Mail
Exchange Accelerator lets remote users choose between an accelerated connection (when connecting over a slow link), a normal connection (when working over a local network connection), or no connection (when working offline). When a remote user chooses an accelerated connection, the Exchange Accelerator client contacts the Exchange Accelerator server, which makes requests of the Exchange server on behalf of the client. A downside to the accelerated connection option is that users can't access Public Folders. However, an easy workaround exists: Restart Microsoft Outlook and select a normal connection. (To learn more about Exchange connection options and how they affect mail delivery, see the sidebar "Are You Getting Your Mail the Fast Way?").

Performance Testing
To test Traveling Software's claim that Exchange Accelerator speeds delivery of email to a user's computer over a remote connection, I devised three tests. The first test gauged Exchange Accelerator's ability to speed delivery of typical email messages. The test used 20 messages, with no attachments, that varied in size from a few lines to six printed pages. The second test used one message with two .doc file attachments to measure the impact when Exchange Accelerator downloaded large attachments that would benefit from data-stream compression. The two .doc files contained several bitmap images and totaled 1MB. The third test used one message with a 1MB .zip file attachment to test whether Exchange Accelerator improves performance when downloading a fully compressed message. To determine whether Exchange Accelerator's effectiveness varies according to which Exchange connection option users choose at startup, I ran all three tests in both the Exchange Connect and Work Offline modes without Exchange Accelerator installed. After installing Exchange Accelerator and choosing the accelerated connection, I ran the tests again.

I used a 333MHz Pentium II Compaq Professional Workstation 6000 with 128MB of RAM as the Exchange Accelerator server for my testing. For the client system, I used a 450MHz Pentium II Compaq Deskpro EN with 64MB of RAM. The client used a Best Data 33.6Kbps modem, which I reset to the factory default configuration. I installed Outlook 98 on the client to deliver messages to a personal folder (.pst file). I set up Exchange Server 5.5 Standard Edition (Exchange 5.5/S) on a 200MHz quad-Pentium Pro Compaq ProLiant 5000 with 512MB of RAM. I dialed into an unbranded NT 4.0 Service Pack 3 (SP3) RAS server with a U.S. Robotics Courier V.Everything X2 modem, which I upgraded with V.90 support.

Each time I sent a test message, I waited until I was sure the message had reached the Exchange server's mailbox. Then, I started up Outlook and recorded the amount of time Exchange took to deliver the message into the personal folder on the client. To test the Exchange Connect mode transfers, I started timing when I clicked the Connect button. To test the Exchange Work Offline mode transfers, I started timing when I clicked the Send and Receive button. Finally, to test Exchange Accelerator's accelerated mode, I started timing when I clicked the Accelerate button. In all cases, I stopped timing when the message (or the last message, when the test included multiple messages) appeared in the Personal Folder Inbox. I ran each set of tests three times. Table 1 reports scores as an average of the three test runs.

As Table 1 shows, the test results are impressive. Exchange's Work Offline mode transferred the 20 messages in the first test suite in slightly less than half the time Connect mode required. Exchange Accelerator's accelerated mode was fastest, completing the transfer in half the time the Work Offline mode required. The second test's results are equally impressive: Exchange Accelerator transferred the message with the 1MB .doc attachments in less than half the time either Exchange mode required. In the third test, however, Exchange Accelerator didn't significantly improve on the times the Connect and Work Offline modes required to transfer one message with a 1MB .zip file attachment.

Enterprise Exchange Accelerator can help speed the transfer of email over a dial-up connection and ensure that the unexpected receipt of messages with large attachments doesn't delay the workflow. At $599 for server software and $60 per seat, the software is affordable. If you must purchase server hardware to use Exchange Accelerator, your implementation costs rise. However, if your remote users are frustrated by slow message transfer and your dial-in costs are high, Exchange Accelerator might be well worth the cost of implementation.