Asterisk provides basic call center functionality via its queueing system, but those who are using it in more mission-critical environments often report that their solutions required customization. You can do this customization in the queues.conf file.
The [general] section of
queues.conf contains settings that will apply to all
queues. If the persistentmembers
parameter is set to yes, a member that
is added to the system via the AddQueueMember() application or through the
Asterisk Manager Interface will be stored in the AstDB, and therefore
retained across a restart.
The autofill parameter allows
Asterisk to be more efficient in the way it distributes calls to queue
members, especially if there are multiple callers in the queue and
multiple queue members available to receive the call. It is recommended
you set autofill to yes.
Another general parameter of queues.conf is MonitorType. If set to MixMonitor, it will mix the inbound and outbound
audio streams. If set to Monitor, it
will revert to the older method of recording the inbound and outbound
audio in separate files.
Next you can define one or more queues by placing its name inside of
square brackets ([]). Within each
queue, the following parameters are available:
musiconhold
This parameter allows you to configure which music-on-hold class (configured in musiconhold.conf) to use for the queue.
announce
When a call is presented to a member of the queue, the prompt
specified by announce will be
played to that agent before the caller is connected. This can be
useful for agents who are logged in to more than one queue. You can
specify either the full path to the file, or a path relative to
/var/lib/asterisk/sounds/.
strategy
Asterisk can use six strategies to distribute calls to agents:
ringall
The queue rings every available agent and connects the call to whichever agent answers first (this is the default).
roundrobin
(deprecated)The queue cycles through the agents until it finds one
who is available to take the call. roundrobin does not take into
account the workload of the agents. Also, because roundrobin always starts with the
first agent in the queue, this strategy is suitable only in an
environment where you want your higher-ranked agents to handle
all calls unless they are busy, in which case the lower-ranked
agents may get a call.
leastrecent
The call is presented to the agent who has not been presented a call for the longest period of time.
fewestcalls
The call is presented to the agent who has received the least amount of calls. This strategy does not take into account the actual agent workloads; it considers only the number of calls they have taken (for example, an agent who has had 3 calls that each lasted for 10 minutes will be preferred over an agent who has had 5 calls each lasting 2 minutes).
random
As its name suggests, the random strategy chooses an agent at random. In a small call center, this strategy may prove to be the most fair.
rrmemory
The queue cycles through the list of queue members, keeping track of which member last received a call. The next time a call needs to be distributed, Asterisk will continue from this point in the list of queue members. (This strategy is known as round-robin memory). This ensures that call presentation cycles through the agents as fairly as possible.
servicelevel
In a call center, the service level represents the maximum
amount of time a caller should ideally have to wait before being
presented to an agent. For example, if servicelevel is set to 60 and the service
level percentage is 80 percent, that means 80 percent of the calls
that came into the queue were presented to an agent in less than 60
seconds.
context
If a context is assigned to a queue, the caller will be able to press a single digit to exit to the corresponding extension within the configured context, if it exists. This action takes the caller out of the queue, which means that she will lose her place in line—be aware of this when you use this feature.
timeout
The timeout value defines
the maximum amount of time (in seconds) to let an agent’s phone ring
before deeming the agent unavailable and placing the call back into
the queue.
retry
When a timeout occurs, the retry value specifies how many seconds to
wait before presenting the call again to an available agent.
weight
The weight parameter
assigns a rank to the queue. If calls are waiting in multiple
queues, those queues with the highest weight values will be presented to agents
first. When you are designing your queues, be aware that this
strategy can prevent a call in a lower-weighted queue from ever
being answered. Always ensure that calls in lower-weighted queues
eventually get promoted to higher-weighted queues to ensure that
they don’t have to hold forever.
maxlen
maxlen is the maximum
number of calls that can be added to the queue before the call goes
to the next priority of the current extension.
announce-frequency
The announce-frequency
value (defined in seconds) determines how often to announce to the
caller his place in the queue and estimated hold time.
announce-holdtime
There are three possible values for this parameter: yes, no, and once. The announce-holdtime parameter determines
whether or not to include the estimated hold time within the
position announcement. If set to once, it will be played to the caller only
once.
monitor-format
This parameter accepts three possible values: wav, gsm, and wav49. By enabling this option, you are
telling Asterisk that you wish to record all completed calls in the
queue in the format specified. If this option is not specified, no
calls will be recorded.
monitor-join
The Monitor() application
in Asterisk normally records either end of the conversation in a
separate file. Setting monitor-join to yes instructs Asterisk to merge the files
at the end of the call. This should be set only if the MonitorType parameter is set to Monitor.
joinempty
This parameter accepts three values: yes, no, and strict. It allows you to determine whether
callers can be added to a queue based on the status of the members
of the queue. The strict option
will not allow callers to join the queue if all members are
unavailable.
leavewhenempty
This parameter determines whether you want your holding callers to be removed from the queue when the conditions preventing a caller from joining exist (i.e., when all of your agents log out and go home).
eventwhencalled
Set eventwhencalled to
yes if you wish to have queue
events presented on the Manager Interface.
eventmemberstatusoff
Setting this parameter to no will generate extra information
pertaining to each queue member.
reportholdtime
If you set this parameter to yes, the amount of time the caller held
before being connected will be announced to the queue member
answering the call.
memberdelay
This parameter defines whether a delay will be inserted between the time when the queue identifies a free agent and the time when the call is connected to that agent.
member =>
member_name
Members of a queue can be either channel types or agents. Any agents you list here must be defined in the agents.conf file.