generation of non-secure warning tones on packet-switched networks, particularly across multiple security domains, locally by the VoIP phone

摘要

The invention relates to a method for supporting non-secure warning tones on packet-switched networks comprising the steps of receiving a call attempt from a source phone (10; 11) to a destination phone (S3.1; S5.1; S7.1), checking if a connection of the security domains of the source phone (10; 11) and the destination phone via a MLS voice gateway (16) is allowed (S3.2-S3.4, S3.7; S5.2-S5.4, S5.7; S7.2-S7.4, S7.6), checking if a generation of a non-secure warning tone locally by the source phone (10; 11) is required (S3.8-S3.10; S5.8-S5.10; S7.7), and establishing a call from the source phone (10; 11) to the destination phone upon acknowledgement of the local generation of the non-secure warning tone by the source phone (10; 11).;ADDITIONAL-DETAILS: in a VoIP communication, generation of a non-secure warning tone (NSWT, audio tone, which, in the prior-art, is delivered in-band in the speech-path, becoming therefore unreliable in a lower quality RTP channel) by the originating VoIP phone on request of a gateway (signal not defined), which expects an acknowledge from the VoIP phone after generation (also not defined); Also, the gateway may generate the NSWT and transmit it in-band, and also a remote security domain warning (RSDW, signaling message displayed on the VoIP phone); the NSWT provides information on multiple levels of security (MLS).