Step 1 Confirm that the CFU service is implemented on the IMS and ask the on-site personnel to perform the following operations:
Capture the network packet about the IAD's success of registering the CFU service when the IAD is directly registered with the IMS.
Capture the logs and network packet about the SoftCo's failure of registering the CFU service when the SoftCo is registered with the IMS.
Provide the information about the prefix and number of the SoftCo for Huawei technical support engineers.
Step 2 Check the configuration. It is found that the SoftCo's calling number for registering services has the local right to make outgoing calls and the value of callattribute of the prefix *57* is local. Therefore, the configuration problems are ruled out.
Step 3 Compare the two INVITE messages from the two captured packets. It is found that when the SoftCo is registered with the IMS, *57*05967095723%23 in the TO field of the INVITE message is sent out but when the IAD is directly registered with the IMS, *57*05967095661# in the TO field of the INVITE message is sent out. It is found that the SoftCo changes # to %23 and sends the *57*05967095661%23 out. The IMS cannot identify %23 and returns a 487 error, as shown in the following figure.
Step 4 Run the config sip convert23tosharp flag off command to disable changing # to %23 by the SoftCo. The problem is solved.