Asterisk IVR: Advance IVR Asterisk (Latest Versions)

A basic IVR works for small teams, but real businesses quickly need more: multiple levels, smart routing, office-hour handling, queue awareness, customer-specific flows, and clean failover.

This is where advanced IVR design in Asterisk matters. Advanced IVR is not about adding more menu options — it is about building decision-based call journeys.

This guide shows how to build advanced IVRs in modern Asterisk (PJSIP-based) using dialplan best practices: reusable contexts, subroutines, variables, database checks, and production-safe looping rules.

What Makes an IVR “Advanced”?

Advanced IVR typically includes:

• Multi-level menus (main menu → department menu)
• Office hours routing (open vs closed)
• Queue-aware routing (if queue too busy, offer callback)
• VIP caller routing (database-driven priority)
• Language selection (Hindi/English) prompts
• Skill-based routing (sales vs support tiers)
• Reusable building blocks (subroutines)

Recommended Folder/Prompt Strategy

For maintainability, keep prompts organized:

/var/lib/asterisk/sounds/custom/ivr/
  main-menu.wav
  sales-menu.wav
  support-menu.wav
  closed.wav
  invalid.wav
  no-input.wav

Use consistent naming and avoid changing filenames often.

Advanced IVR Architecture (Clean Dialplan Structure)

A good structure separates:

• Inbound entry (from-trunk) → only routes into IVR
• Decision logic → office hours, VIP checks, language
• Menu contexts → main menu and submenus
• Destinations → queues, ring groups, voicemail

This makes the IVR readable and scalable.

Step 1 — Main Entry: Decide Open vs Closed

Use a simple time decision first.

[from-trunk]
exten => s,1,Answer()
 same => n,Gosub(ivr-common,s,1)
 same => n,Hangup()

[ivr-common]
exten => s,1,NoOp(IVR common entry)
 same => n,Set(TIMEOUT(digit)=3)
 same => n,Set(TIMEOUT(response)=5)

 ; Example open hours check (Mon-Sat 10:00-19:00)
 same => n,GotoIfTime(10:00-19:00,mon-sat,*,*?open:closed)

 same => n(open),Gosub(ivr-main,s,1)
 same => n,Return()

 same => n(closed),Playback(custom/ivr/closed)
 same => n,Voicemail(1000@default,u)
 same => n,Return()

Step 2 — Main Menu with Controlled Loops

Advanced IVR must avoid infinite loops. Use a counter variable.

[ivr-main]
exten => s,1,NoOp(Main IVR)
 same => n,Set(IVR_TRIES=$[${IF($["${IVR_TRIES}"=""]?0:${IVR_TRIES})}+1])
 same => n,GotoIf($[${IVR_TRIES} > 3]?fail,1)

 same => n,Background(custom/ivr/main-menu)
 same => n,WaitExten(6)

; Sales submenu
exten => 1,1,Gosub(ivr-sales,s,1)
 same => n,Goto(ivr-main,s,1)

; Support submenu
exten => 2,1,Gosub(ivr-support,s,1)
 same => n,Goto(ivr-main,s,1)

; Operator / fallback
exten => 0,1,Goto(destinations,operator,1)

; Invalid
exten => i,1,Playback(custom/ivr/invalid)
 same => n,Goto(ivr-main,s,1)

; No input
exten => t,1,Playback(custom/ivr/no-input)
 same => n,Goto(ivr-main,s,1)

exten => fail,1,Playback(custom/ivr/all-agents-busy)
 same => n,Goto(destinations,operator,1)

Step 3 — Submenus (Sales / Support)

Sales submenu example:

[ivr-sales]
exten => s,1,NoOp(Sales submenu)
 same => n,Background(custom/ivr/sales-menu)
 same => n,WaitExten(6)

; New sales → queue
exten => 1,1,Goto(destinations,sales_queue,1)

; Existing customer → ring group
exten => 2,1,Goto(destinations,sales_ringgroup,1)

; Back to main menu
exten => 9,1,Return()

exten => i,1,Playback(custom/ivr/invalid)
 same => n,Goto(ivr-sales,s,1)

exten => t,1,Return()

Support submenu example:

[ivr-support]
exten => s,1,NoOp(Support submenu)
 same => n,Background(custom/ivr/support-menu)
 same => n,WaitExten(6)

; Technical support
exten => 1,1,Goto(destinations,support_queue,1)

; Complaints
exten => 2,1,Goto(destinations,complaints_queue,1)

; Back
exten => 9,1,Return()

exten => i,1,Playback(custom/ivr/invalid)
 same => n,Goto(ivr-support,s,1)

exten => t,1,Return()

Step 4 — Destinations Context (Single Place for Routing)

Keep all final call actions in one context.

[destinations]
exten => sales_queue,1,Playback(custom/ivr/connecting-sales)
 same => n,Queue(sales,tT)
 same => n,Voicemail(2000@default,u)
 same => n,Hangup()

exten => support_queue,1,Playback(custom/ivr/connecting-support)
 same => n,Queue(support,tT)
 same => n,Voicemail(1000@default,u)
 same => n,Hangup()

exten => complaints_queue,1,Queue(complaints,tT)
 same => n,Voicemail(3000@default,u)
 same => n,Hangup()

exten => sales_ringgroup,1,Dial(PJSIP/1005&PJSIP/1006,20)
 same => n,Hangup()

exten => operator,1,Dial(PJSIP/1000,20)
 same => n,Voicemail(1000@default,u)
 same => n,Hangup()

This makes future maintenance much easier.

Advanced Enhancement: Queue Busy Awareness (Offer Callback)

When queues get overloaded, callers should not wait forever. You can detect current waiting callers from CLI and integrate logic.

Practical approach:

• If queue has too many waiting callers → route to voicemail or callback flow
• Otherwise → enter queue normally

Many businesses implement callback using CRM or external systems. Asterisk dialplan can trigger those workflows via AGI/ARI/HTTP.

Advanced Enhancement: VIP Routing with AstDB

Example VIP flag:

Set(DB(vip/${CALLERID(num)})=yes)

In IVR entry:

same => n,GotoIf($["${DB(vip/${CALLERID(num)})}"="yes"]?vip,1)

exten => vip,1,Playback(custom/ivr/vip-welcome)
 same => n,Queue(priority-support,tT)
 same => n,Hangup()

This provides premium support routing with minimal complexity.

Common Advanced IVR Problems and Fixes

DTMF Works Internally But Not Externally

• Trunk DTMF mode mismatch (RFC4733 vs INFO vs inband)
• Codec mismatch causing inband DTMF loss

Menus Become Unmaintainable

• Too much logic in one context
• Fix: split into common / menu / destinations contexts

Callers Get Stuck in Loops

• No loop counter
• Fix: IVR_TRIES pattern and fail route

Best Practices for Advanced IVRs

• Design menus based on business outcomes, not features
• Keep prompts short and human-recorded
• Limit loops and provide operator fallback
• Separate dialplan into reusable contexts
• Test with real external calls and real SIP trunk conditions

Advanced IVR is a customer experience system — build it like a product, not a script.

Key Takeaway

Advanced IVR in Asterisk is about clean architecture: reusable logic (Gosub), clear menus, controlled looping, office-hour decisions, and smart destinations.

With the right structure, you can scale your IVR from 2 options to a full enterprise call journey without chaos.