Node:
info: [1000]  *** janus about to create room: 1000
handle.message({ "request": "create", "room": 1000, "is_private": true, "sampling_rate": 24000 }).then((rc) => {

info: [1000]  janus room create rc:{"janus":"success","session_id":6649475478469644,"sender":8234236185973044,"transaction":"8366853","plugindata":{"plugin":"janus.plugin.audiobridge","data":{"audiobridge":"created","room":1000,"permanent":false}}}
info: [1000]  *** audioroom janus EVENT: {"audiobridge":"joined","room":1000,"id":7558263621523517,"participants":[]}

Janus Log:
Mar 08 09:40:06 debian8 janus[5671]: Creating a new audiobridge
Mar 08 09:40:06 debian8 janus[5671]: Sampling rate for mixing: 16000
Mar 08 09:40:06 debian8 janus[5671]: Created audiobridge: 1000 (Room 1000, private, secret: no secret, pin: no pin)
Mar 08 09:40:06 debian8 janus[5671]: Audio bridge thread starting...
Mar 08 09:40:06 debian8 janus[5671]: Thread is for mixing room 1000 (Room 1000) at rate 16000...
Mar 08 09:40:06 debian8 janus[5671]: Got a Janus API request from janus.transport.http (0x7f5d5c000eb0)
Mar 08 09:40:06 debian8 janus[5671]: Transport task pool, serving request
Mar 08 09:40:06 debian8 janus[5671]: [8234236185973044] There's a message for JANUS AudioBridge plugin
Mar 08 09:40:06 debian8 janus[5671]: Configuring new participant
Mar 08 09:40:06 debian8 janus[5671]: -- Participant ID: 7558263621523517
Mar 08 09:40:06 debian8 janus[5671]: Creating Opus encoder/decoder (sampling rate 16000)
Mar 08 09:40:06 debian8 janus[5671]: Preparing JSON event as a reply
Mar 08 09:40:06 debian8 janus[5671]: [8234236185973044] Sending event to transport...