2.18.11 MTP Screening

MTP screening features:

• MTP Screening provides a first level of security check for VSTP.
• The MTP Screening feature examines the contents of a Message Signaling Unit (MSU) attempting to enter the VSTP against predefined criteria in the VSTP database to determine if the MSU should be allowed to enter.
• When a message comes on a linkset, the associated screen set will be looked up. Based on the NSFI and rule group name associated with screen set, the rule in the corresponding rule group will be looked up.
• If rule lookup is successful, then message will go for further screening level based on NSFI and the next screen rule group name associated with it.
• If rule lookup does not find a match, then:
  • In case of BLKOPC/BLKDPC rule type, default rule for that rule group will be looked up and based on NSFI and next screen rule group name associated with default rule further screening performed.
  • In case of OPC/SIO/DPC/AFTDSTN rule type, FAIL NSFI will be performed.
• The final result of MTP screening should always be either FAIL or STOP.
  • In case of FAIL, the message will be discarded.
  • In case of STOP, the message will go for further processing in VSTP.