Recently,　both　the　academia　and　industry　have　initiated　research　directed　toward　the　integration　of　software-defined　networking　(SDN)　technologies　into　the　next　generation　of　networking.　In　this　paradigm,　SDN　transfers　the　control　function　from　the　traditional　distributed　network　equipment　to　the　controllable　computing　devices,　which　makes　the　underlying　network　infrastructure　abstract　to　network　services　and　applications.　In　this　study,　we　survey　Open　Flow-based　SDN　solutions　that　were　recently　proposed　in　both　academia　and　industry.　We　consider　technical　issues,　including　SDN　requirement,　Open　Flow-based　approach,　challenges,　and　possible　approaches.　In　addition,　security　breaches　and　possible　solutions　are　described.　Our　survey　is　based　on　recent　research　publications.　©　Springer　International　Publishing　Switzerland　2015.