In some examples, a device detects a calling identifier received as part of initiating a call matches an emergency identifier, the emergency identifier associated with information from which to derive a Uniform Resource Name (URN). The device detects that the device is attached to or registered a first network different from a second network, where the second network configured the emergency identifier. In response to detecting that the device is attached to or registered the first network different from the second network, the device includes a Session Initiation Protocol (SIP) Uniform Resource Identifier (URI) in a Session Initiation Protocol (SIP) INVITE message to be transmitted.

A method for topology hiding is disclosed, comprising: receiving, at a gateway, the gateway positioned between a core network and a radio access network, a configuration information request from a base station; analyzing, at the gateway, a topology of the radio access network, the radio access network including the base station; grouping, at the gateway, the base station into a first group based on the topology; sending, from the gateway to the base station, a grouping message to indicate that the base station be placed in the first group; and terminating connections from the core network to one or more base stations in the first group at the gateway as a back-to-back proxy, thereby hiding the topology of the radio access network from the core network.

A method of operating a call control node in a telecommunications network, the method comprising the steps of: establishing a telephony call between a first user and a second user; receiving a call control instruction, the call control instruction being for associating a to-be-established new call leg, between the call control node and a communications server, with the telephony call; establishing the new call leg between the call control node and the communications server; connecting the new call leg to the telephony call on the basis of the call control instruction, to make the communications server a party to the telephony call.

In some examples, a device detects a calling identifier received as part of initiating a call matches an emergency identifier, the emergency identifier associated with information from which to derive a Uniform Resource Name (URN). The device detects that the device is in a first network different from a second network, where the second network configured the emergency identifier. In response to detecting that the device is in the first network different from the second network, the device includes a URN, urn:service:sos, in a Session Initiation Protocol (SIP) INVITE message to be transmitted.

The subject of the present invention is a method for managing the reception of a telephone call signal on a communication terminal, with a view to the establishment of a telephone link, said telephone link being established by way of a server, said called communication terminal being able to receive the telephone call signal according to at least two modes, comprising a voice mode, in which the telephone link between the called communication terminal and the server is ensured by way of a telephone communication network, and a data mode, in which the telephone link between the called communication terminal and the server is ensured by way of a network for data communication according to a Voice over IP technology, said method comprising the direct selection, by the user of the method, of the mode of establishment of the telephone link. The method comprising the allocating by a call server of a temporary number to the calling communication terminal.

In some examples, a device detects a calling identifier received as part of initiating a call matches an emergency identifier, the emergency identifier associated with information from which to derive a Uniform Resource Name (URN). The device detects that the device is in a first network different from a second network, where the second network configured the emergency identifier. In response to detecting that the device is in the first network different from the second network, the device includes a URN, urn:service:sos, in a Session Initiation Protocol (SIP) INVITE message to be transmitted.

A method for topology hiding is disclosed, comprising: receiving, at a gateway, the gateway positioned between a core network and a radio access network, a configuration information request from a base station; analyzing, at the gateway, a topology of the radio access network, the radio access network including the base station; grouping, at the gateway, the base station into a first group based on the topology; sending, from the gateway to the base station, a grouping message to indicate that the base station be placed in the first group; and terminating connections from the core network to one or more base stations in the first group at the gateway as a back-to-back proxy, thereby hiding the topology of the radio access network from the core network.

In some examples, a device detects a calling identifier received as part of initiating a call matches an emergency identifier, the emergency identifier associated with information from which to derive a Uniform Resource Name (URN). The device detects that the device is in a first network different from a second network, where the second network configured the emergency identifier. In response to detecting that the device is in the first network different from the second network, the device includes a URN, urn:service:sos, in a Session Initiation Protocol (SIP) INVITE message to be transmitted.

In some examples, a device detects a calling identifier received as part of initiating a call matches an emergency identifier, the emergency identifier associated with information from which to derive a Uniform Resource Name (URN). The device detects that the device is in a first network different from a second network, where the second network configured the emergency identifier. In response to detecting that the device is in the first network different from the second network, the device includes a URN, urn:service:sos, in a Session Initiation Protocol (SIP) INVITE message to be transmitted.

A mobile device joins a communication session using a data communication channel. A determination is made the data communication channel uses a data network of the mobile device. A determination is made that, during the communication session, a quality of the data communication channel has decreased. In response to determining that the data communication channel uses the data network of the mobile device and determining that the quality of the data communication channel has decreased, a push notification message is sent to a push notification service. The push notification message comprises a cellular network dial-able number that is used by a cellular application in the mobile device to initiate a call to join the communication session via a cellular communication channel that uses a cellular network.