Do i need to register separately on softphone with Asterisk?

Hello Experts.

I am done with

  1. configuring Asterisk & Openfire.

  2. Configure asterisk in openfire

  3. mapping phone numbers from openfire user to SIP account

if I register to asterisk via softphone and then try to make call from Spark, it’s all good but if i DO NOT REGISTER softphone with ASTERISK, call keeps on failing with message “UNABLE TO REQUEST CHANNEL”.

can someone help please?