APPLICATION SERVICE PROVIDERS

An Application Service Provider (ASP), like an incumbent or next-gen carrier, offers services to end-customers but, unlike carriers, does not have its own facilities. Instead, an ASP runs its services on top of the network of, and in partnership with, an incumbent or next-gen carrier. An ASP's sole focus on delivering one or a few enhanced services often gives it a velocity and cost advantage over the carrier.

Convedia Media Server in an ASP Deployment

The diagram above shows a deployment scenario for an ASP running on top of an incumbent's network in a Service Offload deployment. The media servers in such a network are controlled by the ASP’s softswitches and/or application servers, and provide all the media processing required by all the services of the ASP. Note that multiple softswitches and application servers can control the same media server, and can do so, simultaneously, through any mix of control protocols such as MGCP, SIP, and Megaco.

In a network supporting ASPs, the media servers can be provided either by the carrier or by each ASP. If provided by the carrier, each POP can have its own media server or cluster of media servers serving all ASPs in that POP, or several (or all) POPs can be served by a single cluster, depending on factors such as traffic volume and the cost of carrying traffic across the network, and again serving all ASPs using those POPS. If the media servers are provided by the ASPs, the situation is similar, and the ASP can choose to deploy a media server or cluster of them in each POP, for a group of POPs, or the entire network. All services offered by the ASP are supported from the same media servers.

An alternative deployment is Trunk-Side, where the ASP’s equipment connects directly to the carrier's underlying VoIP infrastructure, without the need for a VoIP/PSTN gateway. The ASP model also applies to next-gen networks, where the ASP's VoIP equipment connects to the network without the need for a gateway.

Unsurprisingly, the voice services that can be offered by an ASP are essential the same as those that an incumbent carrier or next-gen carrier can offer directly: Class 4 (routing-related) services, IP Centrex, voicemail, card services (e.g., prepaid, postpaid), business conferencing (scheduled, on-demand, and instant), and call center (automatic call distribution) services.

All of these services make use of a media server for processing of audio streams, under the control of a softswitch or application server. Here are some examples of how each of the media server's capabilities—also called building blocks—are used by the services:

• announcements: network announcements, service announcements for all services, branding
• IVR: feature programming, feature invocation, voicemail, card, conferencing, call center
• bridging: POTS three-way calls, Centrex six-way calls, conferencing, call center
• play/record: call screening, voicemail, conferencing
• speech recognition, text-to-speech: operator services, directory services, call center