 Ericsson has agreed to buy U.S.-based global cloud-communications provider Vonage VG, -2.09 for 21 a share, with an enterprise value of 6.2 billion, the companies announced on Monday. The deal has been unanimously approved by Vonages board of directors, and will build on Ericssons aims to expand globally in wireless enterprise, offering existing customers an increased share of a market valued at 700 billion by 2030, the Swedish telecoms-equipment maker said. 