Before you begin Asterisk/Capacity installation
This article is the starting point for integrating Asterisk with Capacity Private Cloud ASR and TTS. It covers what you need in place before you begin — host requirements, a known Asterisk compatibility issue to be aware of, and the order in which to work through the installation — and links to the detailed guide for each stage.
Before you start. Installation is performed at the Linux command line. Commands are case-sensitive and must be typed exactly — a single mistyped character will leave the installation incomplete. If you have limited Linux experience, work through each step carefully and verify every command before running it.
Host Requirements
The speech services for Asterisk are supported on the following Linux distributions:
- Red Hat Enterprise Linux (RHEL)
- CentOS (End of life)
The support policy covers the latest two major releases of RHEL/CentOS, on 64-bit operating systems. Before you begin, confirm the host meets these baseline requirements:
- System libraries are current.
- The network card is active.
- A static IP address is configured.
Prebuilt Asterisk distributions. If you are running a prebuilt distribution such as trixbox or elastix, the standard instructions will generally work, but expect to perform additional configuration beyond what these guides cover.
Known Issue: Asterisk 16 and res_speech_unimrcp
There is a known bug in Asterisk v16 with the res_speech_unimrcp module that produces the following error:
[Feb 6 10:48:35] ERROR[17692][C-00000021] astobj2.c: FRACK!, Failed assertion bad magic number 0x0 for object 0x31990d8 (0)
This affects only the Generic Speech API (the res_speech path). The UniMRCP Applications suite — MRCPRecog(), MRCPSynth(), and SynthAndRecog() — is not affected. If you encounter this error on Asterisk 16, use the UniMRCP Applications integration path instead.
Installation Roadmap
Work through the integration in this order. Each step links to its detailed guide:
- Install Capacity Private Cloud, including the Media Server, following the installation instructions.
- Install and configure the Asterisk UniMRCP modules.
- Verify the integration is working.
- Run the sample dialplan applications to test ASR and TTS — see Developing Speech Applications on Asterisk.
- Begin developing your own applications, using Developing Speech Applications on Asterisk and the Generic Speech API overview as references.
If this is your first time installing these components together, the end-to-end walkthrough in Configuring Asterisk 13 — covering Asterisk 13 with UniMRCP 1.3.0 — is a useful companion.