Redswitch

Redswitch is a freeswitch ESL agent that recives jobs via Redis to control Freeswitch.

Configuration

Redswitch can be configured with the following environment variables:

Name	Description	Default Value
ESL_PASSWORD	Password for ESL connection.	ClueCon
ESL_PORT	Port of ESL server.	8021
ESL_URL	URL of ESL server.	127.0.0.1
PUBSUB_REDIS_TIMEOUT	Timeout when connecting to Redis. Integer.	10
PUBSUB_REDIS_URL	URL to Redis cluster.	redis://127.0.0.1:6379

Redswitch Jobs

A Redswitch Job is where initial calls begin a job that can be handled by any instance of Redswitch. Each job directive is associated with a set of expected responses.

ASP Call

An asp call is pushed to talkiq-asp.calls. Because freeswitch hangs up a channel when a call fails, the reasons for a failed call are denoted in the Hangup-Cause.

{
    "type": "asp-call",
    "call_provider": "talk_call_provider",
    "callee_number": "1415697098",
    "caller_id_lega": "15105625882",
    "caller_id_legb": "14157697098",
    "caller_number": "15105625882",
    "dial_id": "talkiq_dial_id",
    "org_id":  "talkiq_org_id",
    "user_id": "talkiq_user_id",
}

Call Control messages

Call control messages are used to control active Redswitch job. Any time a redswitch job is answered, the responsible instance of Redswitch becomes a subscriber to a channel named after the dial_id and it awaits call control messages for the dial_id in question.

• Dial IDs are implicit !!! they are are the channel your working on!

Hangup

{
    "type": "hangup"
}

Barge

Barging creates a new call which allows the barger to listen in on the specified dial_id.

{
    "type": "barge",
    "phone_number": "15105625882",
    "caller_id": "777-777-7777",
}

Whisper

Whisper allows a barger to start talking to the call initiator.

{
    "type": "whisper",
}

Mute (un-whisper)

Mute causes the barger to return to muted.

{
    "type": "mute",
}

Threeway

threeway allows the barger to talk both to the caller and to the callee

{
    "type": "threeway",
}

unthreeway

unthreeway allows the barger to talk both to the caller and to the callee

{
    "type": "unthreeway",
}

Call Events

Call events are events that happen on calls that may not have initiating call control events.

• side 0: phone of the caller
• side 1: phone of the callee

Dial_ids are still implicit.

call-start

call-start is is published when freeswitch initiates the call

{
    "type": "call-start",
    "dial_id": <dial_id>
}

Hangup

{
    "type": "hangup-event",
    "side": "call-side",
    "cause": "see https://wiki.freeswitch.org/wiki/Hangup_Causes",
}

Answer

{
    "type": "answer-event",
    "side": "call-side",
}

<<<<<<< HEAD

Whisper

Whisper allows a barger to start talking to the call initiator.

{
    "type": "whisper",
}

Mute (un-whisper)

Mute causes the barger to return to muted.

{
    "type": "mute",
}

Threeway

threeway allows the barger to talk both to the caller and to the callee

{
    "type": "threeway",
}

unthreeway

unthreeway allows the barger to talk both to the caller and to the callee

{
    "type": "unthreeway",
}

failure

failure gets published to the dial_id when a call will not even be attempted by freeswitch

{
    "type": "failure",
    "cause: "the cause of the failure"
}

Ack

All call control messages respond to acknowledgements as follows

{
    "type": "ack",
    "event": "callcontrol_message"
}

Active Calls

Redswitch keeps track of all active calls in redis, each active call is represented as a list with the fallowing format.

redswitch.<dial_id>.<org_id>.<user_id>

each value of the list represents a call side in the following format

<state>.<side>

• Currently the only state is 'ACTIVE'
• When a side is hung up, the list item is removed
• Active calls expire after 24hrs

Event history

Redsiwitch tracks the event history hisetory of active calls on a per user baises the list is formated as fallows

redswitch_history.<org_id>.<user_id>

• List Values are identical to redswitch events
• Event history is deleted at the start of every new call
• Event historys expire after 4 hrs

Local Dev

Redswitch requires an accessible Redis cluster and a Freeswitch instance.

The shiznit/redis library can be used for the former:

cd /path/to/shiznit/redis
docker-compose up -d

You can connect a local redswitch to the above network and a test Freeswitch instance with

docker build -t redswitch .
docker run --rm --name redswitch --net redis_default -it \
    -e PUBSUB_REDIS_URL=redis://node0:6379 \
    -e ESL_URL=174.36.124.235 \
    -e ESL_PASSWORD=ClueCon \
    -v ${PWD}/redswitch:/src \
    -v ${PWD}/tester:/opt/sensu/service/vader-tester \
    redswitch

You can verify your connections to Redis and Freeswitch with

docker exec redswitch /opt/sensu/service/vader-tester/esl.py
docker exec redswitch /opt/sensu/service/vader-tester/redis.py

You can run lpop.py against it to send test commands with

docker exec redswitch /src/lpop.py --help