White House and congressional operators are being swamped with health-care-related phone calls. Though one "very significant spike" occurred after conservative radio host Rush Limbaugh urged his listeners to register their disapproval, Democrats say the flood of calls also reflects support for reform. Here's a look at the legendary White House telephone line:

1. Who answers when I call the White House?
Depends on which number you call. The public comment line (202-456-1111) is manned by volunteers recruited by the current administration. The White House switchboard (202-456-1414) is manned by professional White House operators. Only privileged parties are privy to the "secret number" that reaches the president directly (see below).

2. How often are the lines jammed by protest calls?
It tends to happen when controversial legislation is up for a vote; both the 2008 Wall Street bailout and 2007 immigration overhaul bill provoked more calls than the system could handle. Reaction to certain cataclysmic events, such as John F. Kennedy's assassination, have also overloaded the presidential phone system.

3. When did the White House first get a telephone?
May 10, 1877, when Rutherford B. Hayes had one installed in the White House telegraph room. The first White House phone number was "1," but the phone was directly connected to just one other early adopter, the Treasury Department. 

4. You mean the president didn't have his own phone?
No, not until Herbert Hoover had one set up in the Oval Office in 1929. And even then, it wasn't a private line until Clinton revamped the White House phone system in 1993. Clinton complained that anyone in the White House could listen in on his calls by picking up an extension and pressing a button. According to a WIRED.com report: "Clinton got a lot of mileage during the early weeks of his administration by telling cocktail-party stories of little old ladies sweating away at the White House's vintage 1960s 'plug-and-play' switchboard."

5. Who is eligible to call the president's "secret number"?
Very few people; the Oval Office number is tightly guarded and routed through a separate switchboard. In a controversial 2007 incident, a 16-year-old teen in Iceland dialed what he mistakenly believed to be the secret number and — posing as Iceland's president — managed to get far as President George W. Bush's secretary.

6. Does the iconic "red phone" still exist?
A telegraph "Hot Line" between the Kremlin and the White House was set up in 1963 after communication lags exacerbated the Cuban Missile Crisis. A direct phone link was set up in 1971, and a fax line added in 1986. Though the "red telephone" seems to have become obsolete, it frequently pops up in fiction and political propaganda — Hillary Clinton's 3 a.m. phone call ad and Glenn Beck's "emergency line to the White House" stunt being recent examples.

History Channel, ABC News, Wired, Time, Wikipedia, Mediabistro, BuzzFlash