HMP Elements supports OPTIONS requests from your carrier. This allows you to control the traffic coming from your carrier. The settings are in the HmpElementsServer.exe.config.
Normally HMP Elements returns a 200OK to all OPTIONS requests. However, if you set this to anything other than 0, it will return the code you specify. (This is a good way to tell a carrier not to send calls here; i.e. if you want to take down the server but there are still calls on it you want to finish up).
<setting name="OptionsMaintResponse" serializeAs="String"> <value>0</value> </setting>
The busy threshold is basically at what point the system starts to report busy here. The OptionsBusyThreshold is the number of lines that MUST remain available to keep from getting a 486; e.g. if you have 500 ports, and you set it to 10, then when you only have 10 ports available, it will start to return BUSY HERE. If you set it to 500, it will always return a busy here.
<setting name="OptionsBusyThreshold" serializeAs="String"> <value>0</value> </setting>
This is the busy response, if 0, it will return 486. Set to anything else will return the value specified (i.e. a 503) when you reach the threshold set above for OptionsBusyThreshold.
<setting name="OptionsBusyResponse" serializeAs="String"> <value>0</value> </setting>
You can change these settings while the system is running. It takes about 10 seconds to update after you save the configuration changes. Just adjust the .config file and viola!