I WAS PACKING when the phone rang.

"Are you still going to Lima?" asked the friend who was calling.

"In about two hours, yes. What do you mean 'still'"?

"Well," she said, "you'd better turn on your radio. There's apparently been some disturbance."

There was indeed a disturbance, complete with blood, but I went anyhow. That was about two years ago. Peru and I both survived, but toward the end of last May it was once again a troubled country. According to news reports, there was a general strike and 31 people were killed in riots over prices.

During the same week there were also disturbances in the Dominican Republic, Zaire and Rhodesia. In the past few months the bad news spotlight has also focused on Italy, Teheran, Beirut, the Philippines, Afghanistan and a host of other places, many of touristic importance.

For the newspaper reader, it's the "normal" passing parade of happenings. But each incident takes on new significance when you happen to be a traveler about to go off on a trip to one of these spots. It doesn't take long to realize that many news reports leave a key question unanswered: What's the effect on tourists? Should your trip be off or on? Should you fly or flee?

Had you been headed for Lima on May 24, you might well have paused to call the Peruvian Embassy in Washington for advice. To see what would happen, I did. I asked for the tourism attache, presented myself as a tourist and asked if it would be safe to go.

"Well, now it is better if you stay here, no? Now is a bad moment to come to Peru . . . I think it is better if you can go in 15 days more," said the official.

His colleague at the consulate in Chicago apparently kept in touch through different channels:

"Now? Well, it's up to you. In Lima, though, nothing happened. No problem."

Really? Everything is functioning?

"Of course!"

There is not even a curfew?

"No, ma'am. Everything is fine."

If you like puzzles, then you'd have loved talking to Peruvian consultate in Los Angeles. Neither the Washington nor Chicago version had reached there. Instead the L.A.-based phone-answerer took the middle ground:

"Maybe now is not the best time, but how you say, sometimes newspapers give it too much and people are very unhappy about it. I think it is pretty safe though . . . There's a curfew, I think, after 11 o'clock. You could ask the airlines," he offered.

Certainly you could - but you might not want to pin all your hopes, dreams and decisions on what they have to say, despite some airline spokespersons' assurances that callers are advised of anything important.

On the first of two calls, the clerks at both Braniff and Aeroperu sounded amazed that I should be asking any questions. "Is something else going on?" asked Braniff's reservationist. When I said yes, she checked further, then reported that there was no message she could find for travelers.

Aeroperu said, oh yes, there had been trouble but it was all over and everything was perfectly normal.

On my second round of calls a few hours later, there were jolts all around. Braniff reported that flights were going in and out normally "now" and that "the curfew is now from 10 p.m. to 5 a.m." At Aeroperu we escalated even more:

"The situation is not good at all. That's about all I can tell you . . . At this moment, yes, the planes are flying but what's going to happen tomorrow or the day after, God knows."

God was unavailable so I called Lufthansa, which also flies to Peru. The response:

"All Lufthansa flights are operating on schedule into Lima."

So how is Lima operating?

"I have no idea," said the clerk, crisply closing the subject.

Aerolineas Argentinas, on the other hand, did have an idea: If I was dissatisfied with what the Peruvian Embassy had to say, I should check the U.S. Immigration Service.

It was an intriguing notion, but I opted instead for the Passport Agency. Since that may sound equally odd, I'd better add that I Knew Something - namely, that the Passport Agency several months ago took over the dissemination of "travel advisories," bulletins from the U.S. State Department about where travel is "iffy" for Americans and where it is officially discouraged.

Moreover, the agency is broadening the scope of the advisories and hopes to report on all situations that could adversely affect Americans - everything from where a disease was broken out to news of currency restrictions (where bringing in too much of the local kind might land a visitor in jail) and tight hotel scenes (places you shouldn't try to go without a room reservation). At this point, more than 80 such directives have been put out, and the public can find out what's up by calling the nearest passport office.

While I give unreserved "hurrahs" for the idea, given the job's immensity I am slightly nervous about its execution. Dark thoughs creep in, too. What happens, for instance, if the leader of a country tells the U.S. ambassador that black is white? Will the ambassador feel forced to buy it, or fearlessly and undiplomatically send out a contradictory report?

In this instance, it developed that the passport offices were telling callers the strike had ended and no further trouble was anticipated. I nonetheless hung up feeling uneasy. I would think, passport office, that you owe it to your public to add "but" to some "all is well" messages. I particularly favor mentioning curfews, a little something that's likely to be meaningful even when it's not momentous. That's because of what happened when I did go to Lima during that 1976 disturbance.

First, I should explain that my "disturbance" commenced on a weekend and State Department desk officers (one or more assigned to keep track of each country) do not customarily work on weekends. And unless it's a really big deal, U.S. consulate staffers may not get around to heating up the Telex lines with reports until Monday. Possibly for one or another such reason, the duty officer sitting in hadn't heard of any problem in Peru, so all I had to go on was a news service story that neither the State Department nor my airline professed to know anything about.

Neither of them even hinted at a curfew, but I found on arrival in Lima that there certainly WAS one. It began at 8 p.m. - so all restaurants took in their last diners at 6:30 and the streets were rolled up shortly thereafter by men with guns and bayonets. Those of us not staying at grand hotels quickly discovered that little places may not be lots of laughs in such circumstances. The help went home, so our food and bar service also ceased around 6:30. For many of us, the only remaining evening activity was reading or listening to a silent city, things tourists might prefer to do in a place that hasn't cost them considerable cash to get to.

There are, of course, places where the scope of the trouble is both greater and immediately apparent; others present no real danger. Yet, as in my Lima experience, there can be acute inconvenience, and so it might be advisable for "travel advisories" to make it standard practice to tell about anything abnormal. Like some curfews, certain strikes and demonstrations can make a big difference in a traveler's life; I'd also like to know when the banks are not doing business as usual.

According to State Department sources, some Americans did indeed have problems in Peru during the troubled period that led up to my call in May. Some reportedly were stuck for several days in Cuzco, unable to get out because of canceled flights and unable to go on to Machu Picchu because the train wasn't running. Initially, a curfew of midnight to 5 a.m. was in force, but the day before I asked my questions, it was extended to begin at 10 p.m. In Lima, the airport road was occasionally blocked by demonstrators, although the airport itself was functioning. Local transport was also hard to come by, and during the general strike most businesses were closed.