What to do about spam calls? Let it go.

Your office phone rings and an unfamiliar number appears on the caller ID screen, perhaps with a 515 or 641 area code. Answering the apparently Iowa-based call is understandable.

Yet often it's an "exciting offer" to reduce student loan debt, a "friendly reminder" about an expiring vehicle warranty or a "helpful warning" about criminal activity linked to your social security number. They're obvious scams, and the phone keeps ringing.

"It is a frustration, and a nuisance," said Korine Spengler, manager of the information technology services (ITS) communication and collaboration team that oversees voice call and videoconferencing services.

So, how should you handle spam phone calls? There is no quick and easy solution to stop them, but here are five things to know if you're getting relentless robocalls at the office.

Let it go

There is nothing wrong with letting an off-campus call to your university phone go to voicemail. If you don't recognize the number and have been receiving spam calls, it's what you should be doing. Not answering is the best tactic for dealing with the interruption of illegitimate phone calls, Spengler said.

Hang up ASAP

As soon as you know a phone call is illegitimate or unwanted, end it immediately. It's often easy to tell if it's a fraud attempt or a sales pitch. There is no need to say anything before hanging up, as there's nothing to be gained by engaging, Spengler said. Never provide personal information to a stranger on the phone.

Difficult to trace

Spoofing, the technology that tricks caller ID, makes tracking the source of illegal calls difficult. While the federal Do Not Call list and its fines worked to limit phone solicitations made by human telemarketers, it's not an effective deterrent for would-be fraudsters who can blast seemingly local robocalls on the cheap from anywhere.

Monitoring traffic

The ITS communication and collaboration team does monitor overall phone traffic volume for major spam call attacks and works to block or reroute them. They're relatively common, occurring every couple weeks on average, Spengler said. Sometimes, team members will call an offending number to try to talk to someone on the other end. "We don't want to block anyone who has a legitimate reason for calling campus," she said.

Added protection

Some ISU employees can't ignore phone calls, of course. If spam calls become a problem at call centers or the main numbers for departments, colleges and units, adding an automated attendant (press 1 to speak with a ...) is an option, Spengler said. "There is a cost, but it is something that we've done for some departments," she said. It's also available for individual office phones.