I am involved in a project to create a series of carrier and enterprise level OpenSER and Asterisk integration training programs. I have been asked to participate due to my direct experience with both OpenSER and Asterisk in many different real-world deployment situations.

However, in order to make this training material more valuable and relevant, I would like to get input from others that are struggling to configure and manage an OpenSER and Asterisk VoIP environment.

Please take a moment and tell me the one biggest problem that you have had with either OpenSER or Asterisk. Please feel free to be detailed as necessary.