Increase max # of TCP/IP Connections on Port 130

Hi,

I have a voice mail system at my office running Windows 2000 Professional.  We also have client software that integrates with Outlook on the PC's to allow users to get their voice mails through Outlook (Unified Messenger).  The problem is that Windows 2000 and XP professional limit the Max # of TCP/IP connections to that particular box to 10, so this means that only 10 people can be connected to the vmail server at any given time.  The software connects on Port 130.

The only thing I have read that may be the answer is to add a value to the registry:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters
Value name: TcpNumConnections
Data Type: REG_DWORD (DWORD Value)

I am not sure if putting in a value of 30, or something will solve my problem or not.  I want some advice before I do this, because if this is indeed what I have to do, I need to reboot the system and would have to do that after hours.  

Also, Upgrading to Windows 2000 Server is not an option for cost reasons and the fact that the company that supports the voice mail software will only support it running on 2000 Pro or XP Pro.

Any advice would be appreciated.

Thanks,
Matt Penney