SIP-Trunked IVR (N2SRP)

IVR for CAMEL/INAP, VXML, or Scripting

The N-Squared Specialized Resource Platform (N2SRP) is the N-Squared IVR platform.

Using industry-standard SIP voice channels, the N2SRP supports voice interaction via a diverse set of service-control mechanisms.

The currently-available protocol mechanisms for N2SRP are:

  1. VoiceXML (2.0 or 2.1) script documents served over HTTP/S.
  2. CAMEL/INAP via SIGTRAN/TCAP PlayAnnouncement or PromptAndCollectUserInformation.
  3. SIP INFO with MSML (RFC 5707).
  4. Local service script written using the Lua scripting language.


Product Information

User & Technical Guide

Protocol Conformance Statements

SIP/RTP Functional Scope

The N2SRP is an IVR node designed to perform RTP audio interaction to a single endpoint, and/or to operate as a SIP back-to-back user agent between the A-Leg and a single B-Leg at any time.

The N2SRP is not a SIP softswitch. The following features and limitations must be considered when determining if the N2SRP is the correct solution for a deployment.

  • N2SRP may originate and/or terminate RTP audio, but will never relay or transcode RTP.
  • N2SRP supports at most one controlled B-Leg at any time, for any given A-Leg SIP INVITE.
  • N2SRP can perform follow-on calling and sequential hunting for consecutive B-Legs.

Note that CAMEL/INAP, VXML, and MSML are extensive protocols which include a wide range of features, not all of which are necessarily supported by the N2SRP. Please refer to the relevant Protocol Conformance Statement to determine which protocol features are currently supported by the product.

Deployment Notes

Platform Sizing

The N-Squared Specialized Resource Platform is a great fit for operators of any size needing a cost-effective, off-the-shelf, standards-based INAP-Controlled or VoiceXML-Controlled IVR, or a powerful locally-scripted IVR service design platform.

The solution supports CAPS rates suitable for operators of any size and is laterally scalable with N+1, 2N, or 2(N+1) deployment for High-Availability, Geographic Redundancy, and traffic growth using active/active or active/passive failover.

OSS/BSS Features

N2SRP has Administration GUIs for audio file management and platform monitoring. Standard Operational features include Alarms, Statistics, and Event Data Records.

The SRP generates Event Data Records including:

  • SIP EDRs describing the SIP voice trunk setup, progress, and teardown.
  • INAP EDRs describing the INAP call-control interaction.
  • VoiceXML Interaction EDRs detailing the VoiceXML call-control actions.
  • RTP EDRs detailing the underlying audio fragment generation.
  • Supplementary (optional) custom service EDRs describing locally scripted service flows.

N2SVCD Components

The N2SRP is built on the N2SVCD framework. The following diagram shows the N2SVCD components which are deployed for N2SRP in CAMEL/INAP controlled mode:

When deployed with VoiceXML control, the N2SVCD deployment is similar:

For additional information on the run-time component configuration of the various N2SRP configurations, refer to the deployment section of the N-Squared N2SIP Technical Guide.

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