"It seems like they are determined to grow share at the cost of margins. We've seen them really aggressively discounting and they're really attempting to displace Cisco in some big accounts, and we've seen them have success doing that," he says.

Existing Juniper partner Radware - another ADC technology provider - is likely to be less pleased by the announcement. That company says its current deal with Juniper remains in place, but spokesperson Mike Lordi declined to comment directly on the new arrangement.

According to Gartner's Fabbi, the new deal provides Juniper with a higher degree of control over the ADC functionality.

The deal with Radware, he says, "is not dead, but certainly from a strategic importance perspective, it's very clear that the investments from Juniper are going to be with the relationship with Riverbed."

Riverbed Chief Marketing Officer David Greene says the agreement helps his company's market share considerably.