Skype for Business Integration with Call Manager

[yemotoye]

Hello All, 

  I am experiencing issues with Skype for business calling to Cisco Call manager but do not have issues with Cisco calling SFB please what could possibly be the issues. 

[#2]

Do you have an error message?
What did you try to check?
Which plan do you have ?

[#3]

On prem? If your mediation servers are collocated with your FEs, make sure your SIP ports aren't stepping on each other. 5060 out to CUCM / 5068 in from CUCM.