Cisco Systems Inc. has lowers its revenue forecast for the next three years because of a weaker demands from emerging markets and telecommunication service providers. The computer networking equipment maker expects average sales growth of 3%-6% in the next couple of years. Cisco's CEO Frank Calderoni said earlier today that these numbers are lower than expected projections for sales to rise 5%-7%. The company is now facing reduced spending from phone companies and corporations, teamed with slower expansion in both Europe and Asian markets.