There is cause for cautious optimism regarding the recent scare about possible alarm signal interference on telephone lines equipped with digital subscriber line (DSL) service. Security Sales has learned that the telecommunications (telco) industry may have changed its DSL installation procedures to lessen the potential for problems. In a conference-call meeting of the Security Industry Association’s (SIA) Telco Networking Compatibility Working Group, Rich Ader of Detection Systems/Radionics said that, according to a technical authority he spoke with at Southwestern Bell Corp. in Dallas, DSL installations after March 1 include filters that should leave alarm signals unaffected. The DSL service would go dead when an alarm signal attempts to seize the line.
This scenario clashes with a March meeting in Las Vegas in which security industry and telco experts concluded that a serious conflict existed between DSL and alarm signals. In an effort to clear up this muddy picture, Virginia Williams, director of Technical and Education Services for SIA, is organizing another meeting with telco representatives. “This is good news if they have changed the DSL standards. I believe the Telecommunications Industry Association (TIA) is reaching out, and it would behoove us to communicate what we require,” she says. “I see this as a real opportunity.”