doc.FAQ.CanIRunMultipleVersionsAtTheSameTime Users like to run multiple driver versions for comparative purposes. Single-Tier users simply install their new drivers to a new directory. Multi-Tier drivers should install their new drivers to different directories, as well. In addition, Multi-Tier users must ensure that their Request Brokers use separate TCP/IP Listen ports. Multi-Tier users need to take the following action:Open their oplrqb.ini files. They will find their oplrqb.ini files in the /bin sub-directories of the OpenLink server components installations. Locate the [Protocol TCP] sections. For example: [Protocol TCP] PingWatchdog = No PingInterval = 600 Listen = 5000 PortLow = 5000 PortHigh = 5025 ;IPAddress = 127.0.0.1 Ensure that each Listen port references a different, unused TCP/IP port. Save any changes to the oplrqb.ini files. Restart or reinitialize their Request Brokers to register any changes they make. Be advised - OpenLink 's 1.x and 3.x software do not have Listen ports. Moreover, these legacy products emit and rely upon UDP broadcasts. Tell your legacy users to take the following action: Open their oplrqb.ini files. They will find their oplrqb.ini files in the /bin sub-directories of the OpenLink server components installations. Locate the [Protocol TCP] sections. For example: [Protocol TCP] PingWatchdog = No PingInterval = 600 Listen = 5000 PortLow = 5000 PortHigh = 5025 ;IPAddress = 127.0.0.1 Ensure that each PortLow port references a different unused TCP/IP port. Ensure that PortLow does not conflict with any Listen or PortLow ports referenced in OpenLink 4.x and 5.x configuration files. Save any changes to the oplrqb.ini files. Restart or reinitialize their Request Brokers to register any changes they make.