IRLP Operating

OVERVIEW

Amateur  radio is receiving a new breath of life through the Internet Radio Linking  Project (IRLP).Many repeaters around the world that previously received  little use are now alive and well with radio amateurs speaking with other hams  all around the world.

The  IRLP consists of a network of repeaters throughout the world connected together  via the Internet.  The system was designed and currently administered by David  Cameron, VE7LTD.  Each repeater is connected to the Internet through a computer  utilizing the Linux operating system.

Dave  designed an interface card and modified existing software to come up with a  nearly seamless system for linking repeaters.  If you want more information on  the IRLP, please visit the website at www.irlp.net.

As  with any new technology, it does take some time to adapt to operating procedures  that differ from conventional FM repeater use. This information can serve as a  guideline for those wishing to use the IRLP on the WIN System.

To view the status of  all IRLP nodes via the Internet, go to status.irlp.net. This is a page that  displays in real time, all of the IRLP activity throughout the world.¬  It also  contains node numbers, locations and repeater frequencies.

CONNECTING MODES

There are two connection modes used on the IRLP  network.  You can establish a direct one-to-one link, or a one-to-many link via  a reflector.

A  direct connection is just like it sounds, where node "A" connects directly with  node "B".  In this mode the two nodes (repeaters) are interconnected and no  other IRLP connections are possible.  While "A" and "B" are linked, anyone  attempting to connect with either node will be informed that - "The node you are calling is currently connected  to <node name / callsign>".

A  one-to-many connection utilizes a reflector to connect many IRLP nodes together  at one time.  A reflector is a computer running special IRLP software.  It is  not connected to a radio, but rather sits on lots of bandwidth capable of  streaming audio to all nodes that are connected.¬  If a direct connection is  attempted to a node linked to a reflector, you will be informed that - "The node you are calling is currently connected  to <reflector name>" 

MAKING A DIRECT  CONNECTION

Identify  with your callsign and the fact that you are controlling, and then enter the ON  code for the node you wish to link with.  The system should come up with a  carrier as it waits for the connection to be established.  You may hear a few  seconds of dead air, so don't be concerned.  When the connection is confirmed,  the voice ID of the destination node will be transmitted back to you.  As well,  the other node will hear your nodeís voice ID on their repeater.  After hearing  the confirming voice ID, wait at least 15 seconds before transmitting to make  sure that you donít interfere with an ongoing conversation.

Due  to the audio delays inherent in a linked system, as well as those added by the  Internet connection, itís important that you adhere to the following practice.   Wait for a couple of seconds after pressing the PTT button before you begin to  speak.  This allows time for all of the links to get established and ensures  that your first few words wonít be cut off.

Some  nodes are configured so that you cannot connect with them if their repeater is  in use.  In this case, you will hear the message, "The node you are calling is being used  locally".  If you hear this message, wait 5 or 10 minutes and then  try again.

You  may also be informed that the other node is currently linked either to another  node or to a reflector.  If theyíre linked to another node, you will have to try  again later.  If theyíre linked to a reflector, you can link to the same  reflector and call them there.

Should  you stay connected to a node and there is no activity for 4 minutes, the  connection may time out and automatically disconnect.  This is dependent on the  other nodeís time out value; our time out value is significantly higher.

When  dropping the link, announce your call and your intent, and then enter the OFF  code.  You should hear a confirming voice ID that the link has been dropped.  If  not heard, try entering the OFF code again. 

CONNECTING TO THE  REFLECTOR

When linking  to a reflector, the connection is established the same way as a direct  connection, the only difference is the node number.  You will hear the voice ID  of the reflector when the link is established.  Anyone currently on the  reflector will not be informed of your presence since no voice IDs are played  over the reflector.

The  most heavily used reflector (Ref 2) is located in Denver.  At any given time  there are usually 6 to 10 repeaters around the world interconnected via the  reflector.  You can always check on who is connected to this or any other  reflector by visiting status.irlp.net and  looking for nodes connected to REF x.

With  reflector use, it is critical that you leave a pause between transmissions.  By  leaving a pause, it allows users on other nodes a chance to check in.  More  importantly, it allows other node controllers the opportunity to send touch-tone  commands to disconnect their node.

As  a rule, connections to the reflectors DO NOT time out with no activity, so itís  not unusual for repeaters with minimal traffic to stay connected to the  reflector for an extended period of time. 

ERROR  MESSAGES

From time-to-time you may receive error messages when  attempting to connect with a node or reflector.  The most common ones  are:

  • "The  node you are calling is not responding, please try again later"   This  is caused by a loss of Internet connectivity at one end of the call  attempt.
  • "Error  - The call attempt has timed out, the connection has been  lost"  This error occurs when a node is offline.  Some nodes, such  as in the UK, use dial-up connections and are not always online.  Also there may  be temporary Internet or node problems.
  • "The  Connection Has Been Lost"  If the Internet connection drops in the  middle of a link, this error message will be heard.

SUMMARY

The  IRLP system is very easy to use and is always a lot of fun.  How else could you  sit in your favorite easy chair with a handheld, and talk to a fellow ham in  Australia.  The most difficult thing about using the IRLP system is getting used  to the difference between local time and the time zone of the other node. 

Thanks go to Dave Griffith, NZ6D, for donating the computer used as the IRLP node on  the WIN System.  As well, thanks also go to Jon Kemper, KA6NVY, for supplying  his skill and help with installation of the link radios and audio  interface and IRLP Ron, VE6RGP, for putting together this document on the IRLP. 


This site Best Viewed with

 Webmaster

W6MYP

All content ©  2006, 2007 WIN  System.org, W6MYP, K6JSI or K6SLS unless otherwise noted. All Rights Reserved.  No  portion of this website may be used, duplicated or distributed in any form   without expressed permission.


Last Updated:

Sunday, November 11, 2007 05:47 PM