Hello.
Thank you for posting on our Huawei forum.
Please be informed that we have checked the product documentation of U1900 regarding the call forwarding feature configuration and usage and there is no detail regarding the time when to forward the call to voice mail at call forwarding busy active.
For the complete feature usage and configuration you can check the link below:
http://support.huawei.com/hedex/hdx.do?lib=EDOC1000073292DEE0403M&docid=EDOC1000073292&lang=en&v=20&tocLib=EDOC1000073292DEE0403M&tocV=20&id=EN-US_TOPIC_0027410900&tocURL=resources%2fftrg%5fu1900%2fen%2dus%5ftopic%5f0027410900%2ehtml&p=t&fe=1&ui=3&keyword=cfb&text=Feature%252BUsageOr you can use the CLI commands below in order to active the service on a user based on your needs and also how to modify the CFB priority for a user
- Modify the priority for CFB for a subscriber:
http://support.huawei.com/hedex/pages/EDOC1000073292DEE0403M/20/EDOC1000073292DEE0403M/20/resources/U1900/cliref/en-us_topic_0032921547.html?ft=0&fe=10&hib=8.2.12.3.9&id=EN-US_TOPIC_0032921547&text=config%20modify%20subscriber%20cfbpriority&docid=EDOC1000073292 - Activate the service:
http://support.huawei.com/hedex/pages/EDOC1000073292DEE0403M/20/EDOC1000073292DEE0403M/20/resources/U1900/cliref/en-us_topic_0032921876.html?ft=0&fe=10&hib=8.2.12.3.2&id=EN-US_TOPIC_0032921876&text=Config%20activeService%20dn&docid=EDOC1000073292Also in order to advise internally and provide a suitable solution or explore the possibility of implementation we would need to know the exact model of the unified gateway used and also the firmware version and the context of this implementation.
Thank you.