The process of warm-transferring your caller to another Agent involves creating a 3-way conference call between yourself and the other two parties.

Then you can leave that conference and the call continues after you hang up.

How to warm-transfer your caller to another ECS Agent.
Using the ECS Agent .NET Toolbar:

1. Click Consult  .
   Click on Contacts, and search for the other Agent or Pod.
   Click the blue Phone icon. .
   When they answer, you are now speaking to the other Agent, and your original caller is on hold.

2. Click Start Conferenceto join all 3 parties together.
   Now all three of you can speak to each other if desired.

3. Click Stop Conference to put both calls on hold.

4. Expand the Telephony Sessions  to make both calls visible, if it's not already.

5. Click Retrieve  to take your original caller off hold.

6. Click Transfer  on the Agent call to complete the transfer. Your original caller is now transferred to the other Agent.

This is a video showing the warm transfer process using two ECS Agents::

ECS-Warm-Transfer-with-3-way-Conference.mp4

How to transfer a call to a Pod Queue Using eAgent.