That was quick. A week after announcing that three members of Cisco Systems' legendary four-person research and development team had been reassigned, CEO Chuck Robbins just announced that they've all resigned instead.

In what appears to be a messy shake-up with hints of an internal power struggle nearing an end, Mario Mazzola, Prem Jain, Luca Cafiero and Soni Jiandani are leaving the company.

The quartet formed what has been a unique-to-Cisco program put in place by Robbins's predecessor, John Chambers, to fund startups that would would build new networking products only to be bought out a few years later. Since the 1990s, the team had spent more than $2 billion on the effort.

As we reported last week, the group had come to be known informally — and for the most part internally — as the "MPLS team." The abbreviation came from their first names, but also coincidentally matched a networking technology that Cisco invented some years ago.

The most recent example of the MPLS team's moves was Insieme, which Cisco funded in 2012 with about $100 million and then acquired for $863 million two years later. It built what's essentially become Cisco's latest generation of switches and routers and has nearly 14,000 customers.

As part of last week's reorganization, Jiandani had been put in charge of Insieme. Now that she's resigned, too, the unit has been placed under David Goeckeler, a senior VP and 16-year Cisco veteran who will now run Cisco's newly created Networking & Security Business Group.

Robbins appears to have been blindsided by the resignations, and said in an internal memo obtained by Recode that their decisions were "based on a disconnect regarding roles, responsibilities and charter that came to light" immediately after last week's announcement.

Cisco didn't comment on the matter beyond sharing a statement attributed to Robbins in which he praised the four engineers for “the countless contributions they have made to Cisco" and noted that "I have personally learned so much from them, and they will always be an important part of Cisco’s engineering story."

Robbins has also been pointing Cisco in new directions. As he explained in an interview with Kara Swisher at last week's Code Conference in Rancho Palos Verdes, Calif., he has bet big on subscriptions coupled with hardware sales. But he has also directed Cisco toward new markets like networks to connect the Internet of Things. Cisco's largest deal in recent memory came earlier this year when it spent $1.4 billion to acquire Jasper, a cloud-based outfit that manages connected devices like cars.