Cause Code Mapping

With the Cause Code Mapping feature, the NOTIFY message sent by CUBE to a Customer Voice Portal (CVP) contains a proper reason for failure of call transfer based on the information received by CUBE from the caller instead of a 503 Service Unavailable message for all scenarios.

Feature Information for Cause Code Mapping

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to https://cfnng.cisco.com/. An account on Cisco.com is not required.
Table 1. Feature Information for Cause Code Mapping

Feature Name

Releases

Feature Information

Cause Code Mapping

Cisco IOS 15.5(1)T

Cisco IOS XE 3.14S

Cisco IOS 15.5(1)T3

Cisco IOS 15.5(1)S3

Cisco IOS 15.5(2)T1

Cisco IOS 15.5(2)S1

Cisco IOS 15.4(3)M4

Cisco IOS 15.4(3)S4

With the Cause Code Mapping feature, the NOTIFY message sent by CUBE to a Customer Voice Portal (CVP) contains a proper reason for failure of call transfer based on the information received by CUBE from the caller. Following are the cause codes supported:

  • 17—486 Busy Here

  • 19—503 Service Unavailable

  • 21—403 Forbidden

  • 31—480 Temporarily Unavailable

  • 102—504 Server Time-out

Cause Code Mapping (Enhancement)

Cisco IOS 15.6(1)T

With the Cause Code Mapping (Enhancement) feature, additional NOTIFY messages are introduced to inform CVP the proper reason for call failures based on the information received by CUBE from the caller instead of a 503 Service Unavailable message for all scenarios.

The following cause codes were introduced:

  • 1—404 Not Found

  • 20—480 Temporarily Unavailable

  • 27—502 Bad Gateway

  • 28—484 Address Incomplete

  • 38—503 Service Unavailable

Cause Code Mapping

If CUBE is configured to consume REFERs that it receives, the following actions occur:

  1. CUBE consumes the REFER that it receives from a Customer Voice Portal (CVP).

  2. CUBE sends an INVITE (instead of a REFER) to the outbound leg (towards the caller).

  3. CUBE receives a status from the caller.

  4. CUBE sends a NOTIFY message to the CVP.

Figure 1. Refer Consume in CUBE

Previously, the NOTIFY message sent in step 4 included a 503 Service Unavailable message irrespective of the reason for failure of call transfer in step 3.

With the Cause Code Mapping feature, the NOTIFY message contains proper reason for failure of call transfer so that the CVP can take an appropriate action.

Table 2. Cause Code Mappings
Status Message received by CUBE

(Step 3)

Cause Code

Notify message sent to CVP

(Step 4)

486 17 486 Busy Here
480 31 480 Temporarily Unavailable
403 21 403 Forbidden
480 19 503 Service Unavailable
504 102 504 Server Time-out

404

1

404 Not Found

480

20

480 Temporarily Unavailable

484

28

484 Address Incomplete

502

27

502 Bad Gateway

503

38

503 Service Unavailable


Note

Cause code mappings for cause code 19 and 21 require configurations mentioned in Configuring Cause Code Mapping.


Note

This mapping is only for the REFER consume scenario and not for REFER passthrough.

Configuring Cause Code Mapping

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. sip-ua
  4. reason-header override
  5. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Device> enable

Enters privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

sip-ua

Example:


Device(config)# sip-ua

Enters the SIP user agent configuration mode.

Step 4

reason-header override

Example:


Device(config-sip-ua)# reason-header override

Configures the sending of a proper reason for failure of call transfer in the NOTIFY message so that the Customer Voice Portal (CVP) can take an appropriate action.

Step 5

end

Example:


Device(config-sip-ua)# end

Exits to privileged EXEC mode.

Verifying Cause Code Mapping

SUMMARY STEPS

  1. Enter the following:
    • debug ccsip function
    • debug ccsip message
    • debug voip application state
    • debug voip application core
    • debug voip ccapi inout

DETAILED STEPS

Enter the following:

  • debug ccsip function
  • debug ccsip message
  • debug voip application state
  • debug voip application core
  • debug voip ccapi inout

Example:

486 Received by CUBE: 

Received: 
SIP/2.0 486 Busy Here
Via: SIP/2.0/UDP 9.40.3.231:5060;branch=z9hG4bK1C15625F7
From: <sip:2222@9.40.3.231>;tag=49B0964D-213C
To: <sip:3333@9.0.0.174>;tag=1
Call-ID: 7D7073E4-3F3B11E4-917BF9A9-A90B2232@9.40.3.231
CSeq: 101 INVITE
Allow-Events: telephone-event
Content-Length: 0
Reason: Q.850;cause=17

486 Busy here response sent in NOTIFY by CUBE 

Sent: 
NOTIFY sip:1111@9.0.0.174:9000 SIP/2.0
Via: SIP/2.0/UDP 9.40.3.231:5060;branch=z9hG4bK1C1571767
From: <sip:2222@9.40.3.231:5060>;tag=49B08E64-1374
To: <sip:1111@9.0.0.174>;tag=1
Call-ID: 1-25970@9.0.0.174
CSeq: 102 NOTIFY
Max-Forwards: 70
Date: Fri, 19 Sep 2014 13:55:46 GMT
User-Agent: Cisco-SIPGateway/IOS-15.5.20140712.124355.
Event: refer
Subscription-State: terminated;reason=noresource
Contact: <sip:2222@9.40.3.231:5060>
Content-Type: message/sipfrag
Content-Length: 25

SIP/2.0 486 Busy here