A computer-implemented technique can include joining, by a computing device having one or more processors, a conference session hosted by a server via a wireless computing network. In response to joining the conference session, the computing device can receive, from the server via the wireless computing network, a dial-in telephone number for reconnecting to the conference session. The computing device can detect a trigger condition indicative of a need to reconnect to the conference session via a cellular telephone network. In response to detecting the trigger condition, the computing device can initiate a telephone call to the dial-in telephone number via the cellular telephone network. In response to the server obtaining authentication of a caller identification of the computing device, the computing device can rejoin the conference session via the cellular telephone network.