System information

If you want to specify a custom key mapping to a feature in an applica-
tion map grouping, simply follow the => with the key mapping you want.
If you do not specify a key mapping, the default key map for that feature
will be used (as found in the [featuremap] section). Regardless of
whether you want to assign a custom key mapping or not, the => oper-
ator is required.
In the dialplan, you would assign this application map grouping with the Set()
application:
Set(__DYNAMIC_FEATURES=shifteight) ; use the double underscore if you want to ensure
; both call legs have the variable assigned.
Parking Lots
A parking lot allows a call to be held in the system without being associated with a
particular extension. The call can then be retrieved by anyone who knows the park
code for that call. This feature is often used in conjunction with an overhead paging
system (PA system, or Tannoy, for our UK readers). For this reason, it is often referred
to as park-and-page; however, it should be noted that parking and paging are in fact
separate.
To park a call in Asterisk, you need to transfer the caller to the feature code assigned
to parking, which is assigned in the features.conf file with the parkext directive. By
default, this is 700:
parkext => 700 ; What extension to dial to park (all parking lots)
You have to wait to complete the transfer until you get the number of the parking
retrieval slot from the system, or you will have no way of retrieving the call. By default
the retrieval slots, assigned with the parkpos directive in features.conf, are numbered
from 701–720:
parkpos => 701-720 ; What extensions to park calls on (defafult parking lot)
Once the call is parked, anyone on the system can retrieve it by dialing the number of
the retrieval slot (parkpos) assigned to that call. The call will then be bridged to the
channel that dialed the retrieval code.
There are two common ways to define how retrieval slots are assigned. This is done
with the findslot directive in the features.conf file. The default method (findslot =>
first) always uses the lowest-numbered slot if it is available, and only assigns higher-
numbered codes if required. The second method (findslot => next) will rotate through
the retrieval codes with each successive park, returning to the first retrieval code after
the last one has been used. Which method you choose will depend on how busy your
parking lots are. If you use parking rarely, the default findslot of first will be best
(people will be used to their parked calls always being in the same slot). If you use
parking a lot (for example, in an automobile dealership), on the other hand, it is far
228 | Chapter 11: Parking and Paging
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