1. Virtual Signaling Transfer Point
  2. Overview of vSTP
  3. Stateful Application Feature
  4. Stateful Security Dynamic Learning
  5. Call Flow in Learn Mode

2.8.4.1 Call Flow in Learn Mode

This mode does not validate any VLRs and consider all the VLRs interacting with the network as valid. All the New VLRs that are used during this modes shall be added to the dynamic tables.

The Learn mode and be changed to Test mode in the following ways:
  • Automatically, upon expiry of the configured learn mode time limit, if configured.

    You can configure the time in number of hours for which the vSTP operates in this mode in SFAPPOPTS table. The recommended time period for Learn mode is 6 to 12 hours.

  • By manual switching of mode

VLR Validation in Learning Mode

The following figure shows the vSTP call flow for VLR validation in learning mode:

Figure 2-16 VLR Validation in Learning Mode


img/vlr-validation-learning-mode.png

  1. The incoming message will be decoded.

    An Error will be generated in case of decode failure.

  2. The message information will be stored in the local database.
  3. Lookup in VLR Whitelist table (static Profile).
    • If entry is found for new VLR, then the validation is skipped.
    • If entry is not found in static Whitelist VLR table, then the lookup is performed in Dynamic Profile Table (DPT).
    • If the entry is not available in DPT, then create it with filter as graylisted, and forward the message to HLR.
    • If entry is avilable in DPT and it is GL, then forward the message to HLR.
  5. Also, Send the Create or Update event to UDR for IMSI record.

Velocity Check in Learning Mode

The following figure shows the vSTP call flow for Velocity check in learning mode:

Figure 2-17 Velocity Check in Learning Mode


img/velocity-check-learning-mode.png

  1. The incoming message will be decoded:
    1. An Error will be generated in case of decode failure.
    2. A Measurement will be pegged for the decode failure with OpCode and CgPA.
  2. The message information will be stored in the local database.
  3. If New VLR entry is not there is Dyn VLR Profile table then create it.
  4. The ATI request will be generated toward the HLR identified in the CdPA of the incoming message.
  5. In case the HLR sends a failure in the ATI response, a measurement will be pegged to identify HLR error corresponding message from CgPA (VLR).
  6. For a success response, extract the Age of Location from the ATI Response message and the VMSC address in the HLR.
  7. In case the New VLR from which the SAI/LU was received matches the old VLR in the ATI response, no action is required.
  8. In case the VLR addresses does not match and old VLR is not available in Dynamic Profile table, then create the entry.
  9. Lookup in Dynamic Roaming table (DRT):
    • If entry is not available, then create the DRT entry with threshold value as AgeofLocation value received in ATI ack.
    • If DRT is already available for the same combination of old VLR and new VLR, and the value of age of location is different than that in the dynamic VLR roaming entry, age of location value in roaming entry is updated to a minimum of the age of location in dynamic VLR roaming entry and the age of location received in ATI ACK. Also Increment the entry_usage_threshold.
  10. Send the update location to HLR and also send CreateorUpdate event to UDR.

If user has configured the switch-mode timer then after expiry of that timer (in hrs), mode will switch to test mode.