Blacklisting means the classification of something as not authorised or not trustworthy. Whitelisting, on the other hand, defines something as trustworthy/approved.
With some of our M2M SIM cards, you have the option of blacklisting certain mobile networks. In this way, you prohibit your end device from connecting to this network, so to speak.
As roaming SIMs, our SIM cards are designed to support many different mobile networks in order to provide your end device with the best possible connection at each location. However, if you know that you do not want to use a particular network, for example because the local connection is subject to very strong fluctuations and your device would therefore connect back and forth very frequently, exclusion via the blacklist may make sense.
The use case may also require the exclusion of individual networks. For example, alarm system installers use our blacklist function to avoid connecting to non-Vds-certified networks.
In addition to mobile networks, there is also the option of adding domains or e-mail addresses to a blacklist or whitelist. The aim here is to limit and protect access to SIM cards. Anything on the blacklist is classified as untrustworthy and is not granted access. What is on the whitelist, on the other hand, is reliable and is allowed access.
You may already know a similar principle regarding blacklisting/whitelisting from your e-mail inbox: If you receive messages that are not clearly classified as trustworthy by the system, they either end up directly in the spam folder or you are asked how this message should be classified.