Foothill Ranch-based AVST, a developer of voice telephony products, has raised $4.0M as part of an ongoing, $18.4M funding round, according to a regulatory filing from the firm Tuesday. No details on the funding have been announced by the company. AVST is backed by Ignition Partners, Dolphin Equity Partners, Open Text, and Escalate Capital. The firm merged in April with Active Voice, a competing provider of call handling and communications products. More information »