Redis database for allocation statuses and for event notifications 
has the following schema:

1) The allocation status is stored as keys "turn/user/<username>/allocation/<id>/status", 
and the values may be "new lifetime=..." or "refreshed lifetime=...". There may be multiple 
allocations under the same user name.

2) Additionally, the same information is reported through the "publish" mechanism. 
The same keys are used and the same status is reported, with the addition of status "deleted".
The user session that is interested in those statuses, must subscribe to the events as:

	psubscribe turn/realm/*/user/*/allocation/*/status

3) Allocation traffic information is reported through the "publish" mechanism.
The keys are "turn/user/<username>/allocation/<id>/traffic". The application that is interested 
in the traffic information must subscribe to the events as:

	psubscribe turn/realm/*/user/*/allocation/*/traffic

Total traffic information is also reported when the allocation is deleted. The keys are
"turn/user/<username>/allocation/<id>/total_traffic". Applications interested in the total amount
of traffic per allocation can subscribe to these events as:

	psubscribe turn/realm/*/user/*/allocation/*/total_traffic
	
Or, to receive all allocation events:

	psubscribe turn/realm/*/user/*/allocation/*

4) Redis database configuration parameters

TURN Server connects to the Redis and keeps the same connection during the 
TURN server lifetime. That means that we have to take care about that 
connection - it must NOT expire.

You have to take care about Redis connection parameters, the timeout and the 
keepalive. The following settings must be in your Redis config file
(/etc/redis.conf or /usr/local/etc/redis.conf):

..........
timeout 0
..........
tcp-keepalive 60
..........
