Harry's Tel/Data Service To Schedule an Estimate, Send Us a Message. has been in business since 1991; we have 25 years experience serving all of Marin County, southern Sonoma and clients in Napa and San Francisco. We do complete data wiring and termination to patch panels and jacks, as well as all telephone wiring and terminations. We sell and service tel systems and customer owned phones. Our rates are very reasonable and we offer guaranteed workmanship. Whether you re moving, changing systems, or repairing your existing system, no job is too large or small.