The primary difference between DigiCipher 2 and DVB lies in how each standard handles SI metadata
, or System Information, where DVB reserves packet identifiers from 16 to 31 for metadata, DigiCipher reserves only packet identifier 8187 for its master guide table
which acts as a look-up table
for all other metadata tables. DigiCipher 2 also extends the MPEG program number
that is assigned for each service in a transport stream with the concept of a virtual channel
number, whereas the DVB system never defined this type of remapping preferring to use a registry of network
identifiers to further differentiate program numbers
from those used in other transport streams.