In a leaked staff email, Cisco boss John Chambers has admitted the one-time technology bellwether and Wall Street favourite has lost its way and will need to change to restore its credibility.

Chambers said the networking giant had been slow to make decisions, fallen down on execution and lacked discipline in an aggressive expansion. He warned staff to to prepare for a number of unspecified changes in the next few weeks and coming fiscal year, starting in August. The long-serving CEO confessed his company let investors down and confused its own employees.

"We have been slow to make decisions, we have had surprises where we should not, and we have lost the accountability that has been a hallmark of our ability to execute consistently for our customers and our shareholders," he said.

Cisco's last two quarterly results have disappointed everyone and its sales have fallen fast.