Covid 19 Update: Given the current global situation, we have paused the delivery of our LiveOnsite courses, but our LiveOnline and OnlineAnytime Packages remain unaffected. Browse over 50 online courses in our course catalogue, or get in touch to register your interest in future LiveOnsite courses when we are able to safely resume in person training.

Blocked Call

A block call results when a call cannot be connected. The two most common reasons for blocked calls are when all lines or trunks to the central office or exchange are in use, or all paths through a PABX (Private Automatic Branch Exchange) or switch are in use. Another example is that of specific services such as premium rate where users request that their local carrier blocks such calls in order to avoid incurring charges.


  • Fully interactive 3GPP based network map
  • Narrated call flows
  • Detailed network procedures

Explore NetX today with a
free trial.
More Info about NetX