Since 2N® VoiceBlue Next communicates using the SIP only, this subsection outlines solutions for its interconnection with networks working with the H.323 signalling protocols. 2N® VoiceBlue Next can be used either in the Point-to-Point or Point-to-Multipoint mode with the SIP Proxy server.
SIP / H.323 Interconnection
SIP-based devices cannot communicate with H.323.supporting devices directly, but through a SIP/H.323 gateway. This gateway transfers signalling messages from/to the protocols. Using the RTP for multimedia data transmission, the SIP and H.323 protocols can go on communicating directly when the SIP/H.323 gateway connection is established. Thus, the SIP/H.323 gateway helps integrate 2N® VoiceBlue Next into the existing H.323 environment.
2N® VoiceBlue Next can communicate with just one SIP VoIP phone or device (a VoIP gateway, e.g.) in the PTP (Point-to-Point) mode. The IP address of the opposite party is always selected as the Proxy server IP address in 2N® VoiceBlue Next for this mode.
The 2N® VoiceBlue Next PTP configuration is often used for testing purposes before implementation into the VoIP network. Refer to the figure below for the PTP scheme.
All calls outbound to GSM are routed to the 2N® VoiceBlue Next gateway in the Point-to-Point mode that uses 2N® VoiceBlue Next.
Point-to-Multipoint is a classical scheme of a distributed VoIP network with one or more SIP Proxy servers (VoIP gateway). The SIP Proxy server is a software PBX (or a standard PBX extended with VoIP services), which is responsible for all VoIP signalling. Multiple source devices (VoIP phones, e.g.) and multiple target devices (2N® VoiceBlue Next, e.g.) can be used in this mode. An internal routing algorithm (Least Cost Router, LCR) of your SIP Proxy is used for routing outgoing GSM and other calls in this mode. Calls to GSM networks can be routed via the 2N® VoiceBlue Next gateways. All SIP signalling is governed by the SIP Proxy server and the subsequent voice stream is based on the Point-to-Point RTP.