Showing results for 
Search instead for 
Did you mean: 
Walkthrough Wednesdays

When a call is initiated from Cisco CallManager 5.x through a SIP Trunk to Cisco CallManager Express, CFNA/CFB does not forward the calls and after the time out, the caller gets a fast busy


Core Issue

The call forwards the no answer and busy destinations to another phone on the same system or to the Cisco Unity Express fails when the call is initiated from a Cisco CallManager 5.0 on a SIP Trunk to Cisco CallManager Express. After the phone rings and the timeout (10s) caller gets a fast busy.


Complete these steps in order to resolve this issue:

voice service voip
  allow-connections sip to sip

   call-forward pattern .T

  1. Ensure that these commands are added in the Cisco CallManager Express Configuration. When this command is used, then on no answer or busy, Cisco CallManager Express sends a 3XX Moved or REFER back to Cisco CallManager and expect the Cisco CallManager to send a new Invite to Cisco Unity Express.
  2. Configure the call-forward b2bua noan command in order to set the Cisco CallManager Express source address as the 302 redirect contact address. Add this command to the incoming dialpeer:

    dial-peer voice 4 voip
    description ** to HQ **
    incoming called-number 40.. 
    !-- Add this
    !-- Add this
    destination-pattern 2...

For more information Command Lookup Tool

Problem Type

Call connection  (Connection quality: One-way audio, no busy tone, dropped calls, etc.)

Call control software  (CallManager, CallManager Express, ICS7750, SRST, SS7 call agents)

Call Control

CallManager express


Call Connection

Call initiation

Reorder tone

Failure Type

Cannot forward or reply

Cannot perform routine, step, function, etc.

SIP Features

SIP trunk

CallManager Versions

CallManager 5.x

Supplementary Services

Call forward