Asterisk PBX functions

Implementing common PBX functions with Asterisk

Some PBX functions in Asterisk are implemented as applications or are supported by a combination of applications that you use in the dial plan. Next to that the different channels implement different subsets of CLASS (or Vertical Service) codes.

general support (for all channels)

Music on Hold: Implemented in Asterisk. See Asterisk cmd MusicOnHold and musiconhold.conf.
__Call Parking__: Supported in the standard installation
Call Pickup: Supported in the standard installation (*8 – defined in res_features.c +55, modify pickupexten in features.conf)
Call Recording: Using the ‘Monitor’ application
Conferencing: Using the ‘MeetMe’ application
IVR: Supported in extensions.conf through the Asterisk applications; employ AGI or EAGI if even more control is needed
DISA: Direct Inwards System Access, Allows someone from outside the telephone switch (PBX) to obtain an “internal” system dialtone.
Voicemail: Voicemail System, For unavailable or busy or no answer status, call can be automatic routed to Voicemail system. Voicemail system has many more attractive features.

for SIP Phones

Call Hold: Normally implemented by your phone
Unattended Transfer (or “blind transfer”): Implemented in Asterisk (#), optionally also in the phone
Consultation Hold: Normally implemented by your phone, for
Unconditional Call Forwarding
Attended Transfer (or “consultative transfer”)
No Answer Call Forwarding: Implemented by yourself in the dial plan. See the tips & tricks page for ideas
Busy Call Forwarding:Implemented by yourself in the dial plan. See the tips & tricks page for ideas
Single-Line Extension:
3-way Calling: Normally implemented by the phone
Incoming Call Screening: Implemented by yourself in the dial plan
Find-Me:
Call Pickup: Supported in the standard installation
Outgoing Call Screening: Implemented by yourself in the dial plan
Automatic Redial: You should be able to implement this in the dial plan with some AGI support
Manual Redial
Do-not-disturb (DND)
Message waiting (MWI): Implemented in Asterisk, but must be support on the phone
Call waiting indication: Implemented in Asterisk, but must be support on the phone

for Analogue Phones connect to Asterisk ZAP channels channel

See Asterisk vertical service activation codes for ZAP channels

Call Hold: Normally implemented by your phone
Unattended Transfer (or “blind transfer”)
Consultation Hold: Normally implemented by your phone, for
Unconditional Call Forwarding
Attended Transfer (or “consultative transfer”): See Asterisk tips zap transfer
No Answer Call Forwarding: Implemented by yourself in the dial plan. See the tips & tricks page for ideas
Busy Call Forwarding:Implemented by yourself in the dial plan. See the tips & tricks page for ideas
Single-Line Extension:
3-way Calling: Normally implemented by the phone
Incoming Call Screening: Implemented by yourself in the dial plan
Find-Me:
Call Pickup: Supported in the standard installation
Outgoing Call Screening: Implemented by yourself in the dial plan
Automatic Redial: You should be able to implement this in the dial plan with some AGI support
Manual Redial

Do-not-disturb (DND)
Message waiting (MWI): Implemented in Asterisk, but must be support on the phone

…..Improved by Nahid Hossain

for MGCP Phones

See Asterisk MGCP channels

Manual Redial: Normally implemented by your phone
Unattended transfer (or “blind transfer”): Implemented in Asterisk (#)
Attended transfer: Implemented in Asterisk (FLASH)
Call Forwarding: Implemented in Asterisk (*72 and *73); optionally implemented in the phone
Call Pickup: Implemented in Asterisk (*8)
Call Waiting Indication: Implemented in Asterisk; disable with *70
Call Number Delivery Blocking: Implemented in Asterisk (*67)
Do-not-disturb (DND): Normally implemented by your phone; also implemented in Asterisk (*78 and *79)
Message waiting (MWI): Implemented in Asterisk, but must be support on the phone

on the CAPI channel

See Asterisk CAPI Channels

Call Deflection (CD) (redirect without answering): Implemented by chan_capi
CLIP & CLIR (display caller ID & hide my caller ID): Implemented by chan_capi
CID & DNID: Implemented by chan_capi
HOLD & RETRIEVE: Hold a call using ISDN (not the PBX): Implemented by chan_capi
Early B3 Connects (always,success,never): Implemented by chan_capi
DID (for Point to Point mode): Implemented by chan_capi

ECT (explicit call transfer): Preserve the orginial CID – Implemented by chan_capi

This page is now beginning to be more complete in any way./OEJ