The cable guy is becoming sleeker and more sophisticated, just like the televisions and computers he installs.

Long depicted as slovenly cranks who dodged growling dogs and tracked mud on the living room carpet, cable guys (and gals) these days often have backgrounds in engineering and computer science. That kind of training is now required — along with a new dress code for some, calling for button-down dress shirts and slacks — as cable companies and their telephone rivals try to lure customers and increase revenue with a suite of products like cloud-based cable boxes and iPad apps that let subscribers set recording times remotely.

All that means added pressure for installers and new requirements for a job that traditionally appealed to high-school graduates looking for reliable blue-collar work.

“Back in my day, you called the phone company, we hooked it up, gave you a phone book and left,” said Paul Holloway, an area manager based in Denton, Tex., and a 30-year employee of Verizon, which offers phone, Internet, television and home monitoring services through its FiOS fiber optic network. “These days people are connecting iPhones, Xboxes and 17 other devices in the home.”