Hello Bandoeng

The post title is the here well known beginning of a 1929 song written by Dutch singer Willy Derby. I am not sure it is still well known today but it certainly was when present day Indonesia was a Dutch colony: the Dutch East Indies (DEI). 
The rather sentimental song is about a mother in Holland calling her dearly missed son in Bandoeng, a large city on the island of Java and over 15,000 kilometers away. In 1979/1980 Soerabaja (also situated on Java) born singer Wieteke van Dort was responsible for a revival of the song. 
In those days making a phone call was an arduous undertaking. I remember when my grandparents wanted to make a call to their daughter in the DEI, a PTT-van* with a transmitter came to their house in The Hague. It was then "flooded" with all kinds of kinds of cables, wires and phones and after hours of preparation the call came into being. I am talking around 1950 now.
This was not the first time for them to communicate with members of the family 

Meinsje Doelman in
Balikpapan (DEI)

in the DEI. My grandmother Antje de Langen-Doelman (1892-1984) had a younger brother and sister who both lived in the East Indies long before WW2. Her sister was Meinsje (Mies) Doelman (1900-1973). She was married to Jan (Bob) Wemmers (1898-1976). He was employed by oil company Shell and a.o. they lived in Balikpapan on the island of Borneo. During WW2 Jan was interned by the Japanese in one of their not so nice camps. His stay there was registered on the card below. Prior to his internment the couple lived in 22 Sawohlaan, Batavia. Later he was transported from the camp to Burma where he was forced to work on the infamous Burma -Thailand railroad. You may remember the movie called Bridge on the River Kwai a.o. starring Sir Alec Guinness and William Holden. Jan survived the railroad but if I remember well, his health was affected.

Japanese camp registration of Jan Wemmers

The brother, Cornelis Doelman (1895-1983), lived in Batavia (currently Jakarta), capital of the DEI. He was a supervisor of poly technical educational institutions in the East Indies. His Belgium born wife Lea Eulalia Hortensia Libert (1896-1983) was with him ever since they moved there after their marriage in 1921.
During the very early stages of WW2 it was possible to send letters from Holland to the DEI. I have one written by Pieter Doelman (1864-1942). He was the father of Antje, Cornelis and Meinsje. At the time he lived in Antje's house on 18 Mispelstraat, The Hague. On May 30, 1940 he wrote about the surrender of Holland and Belgium and about the bombing of Rotterdam ("26,000 houses destroyed"). Also about a relative who was killed in action during the German invasion.  
But apparently the possibility to communicate by mail was stopped a few months

Red Cross message form

later. That is no surprise as obviously the Germans did not allow any connections by air nor by ship. However, there was still the Red Cross. They provided a kind of Short Message Service avant la lettre. There was a maximum of 25 words. On this form Cornelis informs his father in Holland that the DEI family is okay. The date is Oct. 17, 1940. At the time Cornelis is living in 31 Sawohlaan, Batavia, the same street where his sister Meinsje and her husband lived or had been living. The back of this form was used for the return message. The reply was dated Jan. 7, 1941 suggesting a transportation time for these forms of more than 75 days.
Today we live in a world of almost instant communication possibilities anywhere. We have our mobile/cell phones enabling us to call, to WhatsApp, to ping, to SMS and what have you. And in case you are out of reach of 3G and even 4G networks, there is always the satellite phone. For youngsters such as our grandchildren it may be good to know that it wasn't always like this. People wrote letters that took a month or more to reach their destination. People did not have phones in their homes, one had to go to the Post Office to place a call to a neighboring city. International calls? Call the international operator please; they would return the call when the connection was made. All these changes came about in the course of the last 60, 70 years. But it is good to realize that the world wasn't always as near and as small as it is today.

*PTT is short for Post, Telephone and Telegraph, the governmental provider of all these services.