Cisco has clung to its integrated model – hardware and software inextricably bound together – for longer than most companies, but even the router giant has to accept the changes to its world, wrought by white box hardware, open source software and multivendor interoperability. So the company has made one of its most radical changes of direction ever, agreeing to sell some of its software, particularly for service providers, separately from its hardware, and enabling the software to run on third party devices. This reveals the pressure Cisco is under, as its market share in core sectors, such as switching, has declined (though in data center switching it is still over 50%), partly because of challenges from companies which do…