Can only see one of my friend's tracks

[Johnhooker]

I hagot my focusrite interface to work and it's great fun.  It really works.  I hope this lasts forever.  I only have one problem and it's a small one-when playing with my friend, I can only see one of  his two tracks at my end.  I can see his electric guitar track, but not his microphone.  He has the same problem at his end.  At my end I can see both my tracks.  Can anyone suggest a way to fix this?

Thanks for any help.