Much like the recent Comverse/NetCentrex deal, this is another sign of consolidation in the VoIP market, as small and mid-sized vendors bulk up to keep pace with the incumbent vendors, who are all trying to sell into a carrier market that itself is consolidating.
In this case, however, the companies have more common ground in terms their product mix. Maybe for AudioCodes, the $90 million investment is a price worth paying to have one less vendor to compete against. On a business level, as the Light Reading article notes, the move gives AudioCodes a nice entree into the North American cable market, which has lots of room to grow.
Nuera has always remained small - only $16 million in sales - which seems to have been the fate of many nextgen vendors who have been acquired recently, such as VocalTec, VocalData, Jasomi and Kagoor.
Just a quick aside - it's interesting to note how this is another case of an Israeli company growing through acquisition, just like Comverse.