= doc.FAQ.CanIRunMultipleVersionsAtTheSameTime

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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.  

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