nikaah on the phone

Q: I recently did my Nikkah over the phone. My husband lives 100 miles away from me. He was at the Masjid with his two witnesses plus the Imam and I was at home. The Imam called me, asked me questions regarding to the Marriage also asked my wali which was my 16 year old son if he excepted this Marriage which of corse he agreed. Please can you tell me if my nikaah is valid?