Ericsson Low Power Wide Area Networks (LPWAN) are wireless technologies covering different Internet of Things (IoT) applications. The common characteristics for LPWANs are large coverage, low bandwidth, small data sizes and long battery life operation. One of these technologies include Narrowband Internet of Things (NB-IoT) developed and standardized by 3GPP. This document is an informational overview to NB-IoT and gives the principal characteristics and restrictions of this technology in order to help with the IETF work for providing IPv6 connectivity to NB-IoT along with other LPWANs.