I use Cisco ASR920 with Cisco IOS XE Software (PPC_LINUX_IOSD-UNIVERSALK9_NPE-M), Version 16.8.1b, RELEASE SOFTWARE (fc1) and I can not create a sub-interface.
I'm looking for a good IOS sofware which can permit me to create a sub-interface on Cisco ASR920 router.
Thanks in advance for your help.
The ASR-920 doesn't support subinterfaces.
You'll have to build out a service instance in a bridge domain and then use a BVI.
I would highly recommend watching this video series for configuring interfaces on the ASR 920. While the purpose of the video series is to configure TDM pseudowires, they do cover configuring service instances and bridge domains with IP addresses as part of the underlay topology.
A good aspect of these videos is that they provide best practice guidelines for these configurations.
That is correct. Even though the Cisco ASR 900-series and 920-series routers use IOS-XE, it's the carrier Ethernet flavor of XE.
Configuring the service instances and BDI's is not difficult.
Those videos are fairly short, and will fill you in on the config.