Seattle-based Citel Technologies, which helps companies migrate from old telephone systems to Internet-based ones, intends to raise money through AIM, or the Alternative Investment Market, a London Stock Exchange.

Citel, which deploys VoIP without making companies buy all new hardware, plans to raise 10 million pounds, or roughly $18.7 million.

Vonage, which provides consumer VoIP in the U.S., went public on the New York Stock Exchange last week. It has faced lawsuits for setting aside a portion of its $531 million IPO for its customers.