Abstract: A method for supporting non-secure warning tones on packet-switched networks involves receiving a call attempt from a source phone to a destination phone, checking if a connection of the security domains of the source phone and the destination phone via a MLS voice gateway is allowed, and checking if a generation of a non-secure warning tone locally by the source phone is required. A call is established from the source phone to the destination phone upon acknowledgement of the local generation of the non-secure warning tone by the source phone.

Abstract: A voice gateway receives packets transmitting voice data between two voice gateways, each received packet includes header data and voice media payload, means for establishing a voice trunk between the two voice gateways based on the header data of the received packets. The voice media payloads of the received packets are extracted and combined into a single packet, the single packet including for a voice call a dedicated channel data of the established voice trunk comprising an identifier of the respective voice call and the voice media payload of the respective voice call. A single set of header data is added to the single packet, the single set of header data includes base information for synchronizing the flow of data between the two voice gateways. The single packet is transmitted to the receiving voice gateway via the voice trunk.

Abstract: A voice gateway receives packets transmitting voice data between two voice gateways, each received packet includes header data and voice media payload, means for establishing a voice trunk between the two voice gateways based on the header data of the received packets. The voice media payloads of the received packets are extracted and combined into a single packet, the single packet including for a voice call a dedicated channel data of the established voice trunk comprising an identifier of the respective voice call and the voice media payload of the respective voice call. A single set of header data is added to the single packet, the single set of header data includes base information for synchronizing the flow of data between the two voice gateways. The single packet is transmitted to the receiving voice gateway via the voice trunk.

Abstract: A method for supporting non-secure warning tones on packet-switched networks involves receiving a call attempt from a source phone to a destination phone, checking if a connection of the security domains of the source phone and the destination phone via a MLS voice gateway is allowed, and checking if a generation of a non-secure warning tone locally by the source phone is required. A call is established from the source phone to the destination phone upon acknowledgement of the local generation of the non-secure warning tone by the source phone.

Abstract: A method of reading and updating a packet header of an optical packet for transmission over an optical network involves dividing the input signal into two paths. The signal in one path (46) is converted into an electrical signal and the header information is read. The data stored in the packet header is removed optically in the other path (44) by constraining the packet header signal to have a constant amplitude. Updated header information is used to modify the constant amplitude signal using a modulator (60). An apparatus is provided for implementing the method. The header is thus read in the electrical domain, but it is updated optically.