“They had been installed over the decades by different organizations using different standards, different techniques, from different eras,” Mr. Recordon said. “They were finding these pipes that just had bundles of cable that had been cut off over the years, no longer used. So we just started pulling it out.”

With the wiring fixed, Mr. Recordon started replacing computers (the new ones have fast, solid-state drives and modern processors) and color printers. The new phone system — the first since the Clinton years — is all digital, with built-in speakerphones and speed-dial buttons that can be changed online. Many White House aides now carry the most recent iPhones. Mr. Obama, however, still carries a specially modified, highly secure BlackBerry.

The Wi-Fi in the Roosevelt Room is finally strong enough to live-stream an event on Facebook, like White House aides did last week when Mr. Obama surprised former federal inmates whose sentences had been commuted. Forgotten passwords are no longer an irritant now that the White House has started requiring users to log on with a chip-enabled smart card and a pin code.

Mr. Recordon’s team also designed a new web-based system for admitting visitors to the West Wing that can be managed securely from any computer, including ones outside the White House complex.

To be sure, some important West Wing technology was upgraded by the George W. Bush administration, which overhauled the Situation Room for the first time since the Kennedy administration and added modern communications gear. Joe Hagin, the deputy chief of staff for Mr. Bush, recalled having to replace the phones in the presidential limousine after Mr. Bush complained that he had not been able to make a single phone call from his motorcade over an entire weekend.

“He said to me, ‘What the heck would happen if there were a true national emergency?’ ” Mr. Hagin recalled. That fear came true months later on Sept. 11, 2001, when communications glitches plagued the government and led to new equipment in Air Force One and the first BlackBerries in the White House.

Mr. Hagin’s team also upgraded the Intel 486 computers and got rid of the slow and cumbersome Lotus Notes email system. But the speed of technological advancement has once again left the current White House behind.