What is Voice over IP? Voice over IP is a set of protocols that allows you to perform telephony voice communications over a standard Ethernet IP network instead of over dedicated switched telephony voice channels and trunk circuits using ISDN or channel associated signaling.
How does Voice over IP work? Voice and signaling are sent using standard IP protocols (TCP/UDP) over a physical link such as an Ethernet network. This exchange of signaling and voice information takes place in both directions at the same time with each endpoint sending and receiving information over the IP network.
Components of a VoIP network There are three main components of a VoIP network: user agents, gateways, and proxy servers.
How many voice channels can a VoIP system support? As with a PSTN Blueworx Voice Response telephony configuration, the number of channels available on each pSeries computeror BladeCenter computer depends on the number of adapters installed in the system unit.
Compression Blueworx Voice Response VoIP supports both compressed and uncompressed data over RTP streams.
SIP signaling In a Blueworx Voice Response Voice over IP system, signaling information is sent and received through the AIX system unit LAN connection (usually Ethernet). This should be connected to an IP network such that all other SIP UAs (such as gateways, and phones) can contact each other over the network.
Application support With Voice over IP, most inbound or outbound only applications will work unmodified. However, SIP capability can be further exploited if required (see Voice over IP tags).
Outbound arbitrary SIP headers
The Blueworx Voice Response APIs can be used to specify headers and header data that are sent in certain outgoing SIP messages. This allows the state table, VXML and CCXML APIs to specify headers and associated values in outbound SIP messages: