ASP stands for Assistant Superintandent Police, DSP stands for Deputy Superintandent Police. ASP and DSP both are of BPS 17, however, an ASP is a comissioned officer and starts his carrer with ASP rank and can promote upto IG rank whereas an employee reaches to DSP rank after serving 25 to 30 years in service and in rear cases can promote upto SP or SSP and than retires.