Abstract: The disclosed technology performs an automatic update of a Mobile Station International Subscriber Directory Number (MSISDN) change to at least a subset of contacts associated with a user account. Upon receiving an indication of a MSISDN change associated with an account, a contact update server of a telecommunications network retrieves contact information that includes multiple contacts of the account with multiple identifiers. The contact update server generates short messaging service (SMS) messages to be delivered to the multiple contacts of the account based on the multiple identifiers. The SMS messages include information regarding the MSISDN change associated with the account. The contact update server transfers the SMS messages to a short message service center (SMSC), and the SMSC delivers the SMS messages to the multiple contacts of the account.

Abstract: A system receives an electronic message over the internet at a WebRTC gateway (WRG) of a telecommunications network. The system forwards the electronic message to a call session control function (CSCF) using session initiation protocol (SIP). The system detects a failed delivery of the electronic message at a rich communication service configured to deliver and monitor delivery of the electronic message and report failed deliveries. The system generates a failed delivery notification indicating that the electronic message was not delivered. The system receives the failed delivery notification at the WRG and at the WRG converts the electronic message to either a short messaging service (SMS) or multimedia messaging service (MMS) message. The system sends the SMS or MMS message from the WRG to the CSCF using SIP. The system forwards the SMS or MMS message to a short message service center (SMSC), which delivers the SMS or MMS message.

Abstract: An open group chat (OGC) session is initiated between mobile devices registered to different telecommunications networks by first verifying whether each implicated network has a network-to-network interface (NNI) agreement with each other network. A first mobile device receives a request to initiate an OGC session between the first mobile device, a second mobile device registered to a second telecommunications network, and a third mobile device registered to a third telecommunications network. The first device determines, based on a response received from the second network, if an operator of the second network and an operator of the third network have an NNI agreement. If the received response indicates the operators of the second and third networks do not have an NNI agreement, the first mobile device sends a non-OGC message, such as a multimedia messaging service (MMS) message or a closed group chat (CGC) message, to the second and third devices.