Configuring SCCP ALG in ScreenOS Devices (NSM Procedure)
To configure SCCP ALG:
In the NSM navigation tree, select Device Manager > Devices.
Select a security device and then double-click the device on which you want to modify the ALG section. The device configuration appears.
In the device navigation tree, select Advanced > ALGs.
Select Enable SCCP ALG.
Click the Show button to expand the SIP settings.
Use the Up or Down arrow keys to specify the inactive media timeout. The default setting is 120 seconds.
Select the Enable Call Flood Protection to Call Manager check box. The feature is not enabled by default.
Enter a threshold value for the maximum number of calls per minute. The default is 20 calls per minute.
The threshold value is per client to protect the CallManager from being flooded with new calls either by an already compromised connected client or a faulty device.
Select Pass unidentified Skinny message in Route mode check box.
Select Pass unidentified Skinny message in NAT mode check box.
When you select the “pass unidentified message” option in either Route or NAT mode, the message that had an error in decoding (because of unidentified message ID or parameter) is forwarded as-is without any processing.
Click OK to apply your settings.