slackbuilds_ponce/ham/svxlink

The SvxLink project is developing a flexible, general purpose voice
services system for ham radio use.
The SvxLink Server consists of a core that handles the connection to
the transceiver. The core can be configured to act as a repeater
controller or to operate on a simplex channel. The voice services are
loaded into the core as plugins.
The project also includes an EchoLink client GUI application (Qtel).

You can build only svxlink server (no Qtel) by passing QTEL=NO to the script:
QTEL=NO ./svxlink.SlackBuild

Opus is an optional (and, based on the audio quality, suggested!) 
dependency available from slackbuilds.org

You need a "svxlink" user and group:

 # groupadd -g 286 svxlink
 # useradd -u 286 -g svxlink -d /var/spool/svxlink -s /bin/false svxlink

The recommended uid/gid is 286, you may want to check
http://slackbuilds.org/uid_gid.txt for other recommendations.