The Internet Radio Linking Project (IRLP) links amateur radio stations around the world through the Internet by making use of the Voice over the Internet Protocol (VoIP).  This system is not unlike a VoIP based public land mobile network such as Skype or a VoIP based telephone system.  Rather than having a computer-Internet-computer (as in Skype) or a telephone-Internet-telephone (as in a VoIP telephone system), IRLP has a HAM radio-Internet-HAM radio system.  Internet access is typically another computer that takes the signal from the radio and turns it into a data stream that is then directed through the Internet to a designated IP address and station.  The data stream is then converted back to a radio signal and transmitted on the radio at the other end.  The central station with Internet access is called an IRLP Node.  The local IRLP Node can be instructed where the data stream is to go by use of DTMF tones on the user's radio (typically a handheld VHF or UHF radio).  Each node has a unique 4-digit node number assigned in the range of 1000-8999.  As of 2019 there were 1,500 active nodes.

There are two types of nodes - node to node and a node to reflector.  The IRLP node for VE8YK, run by the Yellowknife Amateur Radio Society, is numbered 1642.  At the time of writing this article, it was not operational.  VE8RT is currently working on upgrading the operating system so that the IRLP node may be run on Linux.  For a note to function, the following equipment is needed (from Wikipedia):

• A dedicated IBM compatible computer, Pentium class (Intel, AMD etc.), running a processor clocked at least 200 MHz
• At least 128 MB of RAM
• A dedicated hard drive of at least 2 GB
• Basic (legacy) parallel port running LPT1 (0x378/9)
• Soundcard – most PCI cards work as do many motherboard based chipsets
• Ethernet Adapter (Network Card) connected to the Internet

The node to reflector is where a station speaks to 3 or more nodes at the same time.  This is called an IRLP Reflector.  It is not unlike a "party line" or a radio net. (This is why YARS's former general email distribution was called the "email reflector")

IRLP was invented in the late 1990s at the University of British Columbia.  A directory of nodes is available at http://status.irlp.net/pdf/StatusByCTYPVCT.pdf . 

IRLP is a good way to speak with amateurs around the world or down south.  It is however reliant on public infrastructure (i.e. the Internet).  Nevertheless for users with only the Basic Qualification, it allows them to speak with other amateurs around the world just on a low power VHF or UHF handheld radio.  There are similar systems including Echolink.  I recall having a QSO with a station in Bradford, England and the operator was so excited that he sent me a QSL card (which was quite an achievement for him as he was blind).

Links:

• http://www.irlp.net/ 
• http://irlp.net/pi/directions.txt {IRLP on a raspberry pi?}
• http://www.repeater-builder.com/irlp/irlp-index.html 
• Echolink
• eQSO