By Michael Illingby VE7TFD and David Cameron VE7LTD last updated January 18, 2006
This list is updated with good questions that are received on the questions mailing list. If the question you have is not listed below, please email us.
All links are activated and de-activated by using DTMF
tones received by the IRLP radio/computer. You must contact your local
node operator for access details. IRLP has no control over which
pre-access code some nodes may choose to use to connect and disconnect. <return to FAQ
index>
Q. I live in an area with an IRLP node. How do I get ON/OFF codes?
The node ID codes are now freely distributed . Some
owners/clubs may charge a fee for codes to help support their club and to
offset the cost of setting up and running the IRLP node. Please contact your
local club to determine the need for membership and for the local IRLP link
codes as some nodes require a prefix code similar to an auto patch access
code.
Go to the status page
and click on node number in your area. An email link to the node owner
is provided. <return to FAQ
index>
No. All you need is a radio compatible with your
local IRLP enabled node frequencies. An IRLP board and Linux software
is ONLY required if you wish to establish your own node. <return to FAQ
index>
Q. What are the minimum requirements of the computer?
The minimum required computer is a P133 or better with 96
megs of RAM. The computer must have a sound card
(most PCI
cards work), video card, network card, and working parallel port on LPT1. <return to FAQ
index>
Q. What are the minimum requirements of the link radio?
Any type of link radio will do, as long as you can pull
some type of COS (Carrier Operated Squelch) signal from it. We use several
different types of link radios such as the Kenwood TK-805D UHF, Alinco
mono-bander mobile. As well the old surplus GE Phoenix and Motorola GM300
M120 series synthesized radios are plug and play. In some situations, such
as the Vancouver node, no link radio is used at all because the node is
hooked directly to the repeater. <return to FAQ
index>
Q. What is the minimum internet connection required?
A cable modem or xDSL work great. The connection MUST be
able to sustain 40000 bps (4K/sec). No connections less than that will work
with the IRLP. <return to FAQ
index>
Q. Do I need a Static (fixed) IP address or a Hostname to install the IRLP on my
system?
No. The system can be configured to operate on a
Dynamic(variable) IP (DHCP). Static hostnames are beneficial but
unnecessary as the IRLP system uses its own DNS to resolve IP addresses <return to FAQ
index>
Q. What does the Internet Radio Linking Project hope to accomplish?
The purpose of the project is to bring amateur radio
operators an inexpensive linking system as a way to talk to many other sites
using state-of-the-art-technology. <return to FAQ
index>
Q. Who is responsible for IRLP?
David Cameron, VE7LTD, is originally responsible for the
project roots. Dave and Michael Illingby, VE7TFD, set up the first two
nodes to link between Vancouver and Vernon, BC. Dave is now assisted
by many volunteers around the world. <return to FAQ
index>
Q. What Operating System does the linking software run on?
The IRLP runs solely under the open source Fedora Core 3
version of Linux. The software was designed in Linux to get away from the
Windows operating system. We are never going back so don't ask :) <return to FAQ
index>
Q. Why does IRLP only run on Linux, and is there a particular version of Linux
preferred?
All new IRLP nodes are now being built for Fedora Core 3.
We run LINUX in general for the following reasons:
1) Windows applications are prone to crashing. Most IRLP node
uptimes are measured in months or years, not days.
2) Linux
uses the resources of the machine much better. To run the equivalent system
under Windows, you would require a much more powerful machine.
3) The windows operating system cost money. Linux and Speak
Freely are FREE.
4) There is no remote updating features under Windows that do
not require a reboot. All IRLP and Fedora updates are performed
automatically each evening and never require restarting the computer.
5) Windows has no remote connections that are easily set up.
All IRLP nodes can be remotely accessed via secure shell from any internet
connected machine.
We have to update the software as updates become
available, IRLP and Fedora updates are performed automatically and never
require a reboot. Windows lacks the features for smooth updating.. <return to FAQ
index>
Q. What is this about an IRLP Mailing List, and how do I get in on it? Is there
a cost to join?
IRLP requires that there be NO courtesy tones, CWIDs or
hang time be passed through on the system. This can easily be accomplished
using CTCSS encoder on the repeater TX that follows the receiver COS. <return to FAQ
index>
Q. Do I need a repeater or can I use a IRLP on simplex?
Simplex is perfectly OK however you must be aware of local
regulations as some countries restrict VoIP operation to certain bands or
frequencies. It is also highly recommended that Tone Coded Squelch be
used especially on simplex nodes. <return to FAQ
index>
Q. How many nodes can be joined at any one time?
This is one of the greatest advantages of the way IRLP
functions. Each station, or node, has the ability to connect to another node
directly, or by the way of a reflector, to several other nodes (virtually
limitless). <return to FAQ
index>
Q. What is a reflector?
A reflector can be seen as a digital repeater of sorts. It
takes one digital bit stream in, and repeats that bitstream to all other
connected sites making a digital "partyline". <return to FAQ
index>
Q. What is required to establish a reflector?
You require a STATIC IP and since more than 4 connections
would require more bandwidth than what is provided by DSL or Cable modem a
full T1 or better would be required. All of the current reflectors utilize
at minimum a full bi-directional T1 (1.54mb)
Each connection requires about 32 kb of "sustained" bandwidth
As for the machine any higher end Pentium 166 or better with 64 meg of RAM
(the more the better) , a 1G HD and a NIC card will do. No sound card
required.
All Reflectors utilize special software which is administered by Dave VE7LTD
who you should contact for more details
dcameron@irlp.net
Having said that we have so much surplus bandwidth and unused sub channels of
existing reflectors we strongly urge you to contact a reflector operator and
ask for a sub channel assignment. <return to FAQ
index>
Q. If for example, Aukland NZ, is linked to Orlando FL, can we link our
node elsewhere without interrupting or affecting the original QSO?
Most definitely. Without using reflectors, any two nodes
can link together and converse without affecting the ability for other nodes
to talk to each other. <return to FAQ
index>
Q. If you can converse without reflectors, then why are they available?
Reflectors have been designed so that we can link three or
more nodes together for a QSO. To date the record so far is about 42 nodes
connected simultaneously. <return to FAQ
index>
Q. How does the system work? Can it be explained step by step?
The system starts by receiving audio into a radio that has
been modified to interface with a computer (using the IRLP interface board).
When a signal is received by the radio, the COS state changes. This change
is then sent to the interface board, which tells the computer that the COS
line is active. This change is picked up by the IRLP software and the
computer starts sending a packet stream containing the audio from the
receiver.
This audio is picked up by the connected computer(s) and played out the sound
card. The IRLP software detects the incoming packets and sends a PTT signal to
the link radio. Hence the audio from one end is heard on the other. <return to FAQ
index>
Q. Can I build my own board and save some money? Can I use my own install of
Linux?
No. We are manufacturing the boards at this time. Nothing
but problems and headaches have come so far from user-built boards. <return to FAQ
index>
Q. Does the sound blaster card run in full or half duplex (I think the SB16 I
have will only run In half duplex)?
The system "can" run full duplex, but we are only using it
in half duplex mode at this time. Since the nature of amateur radio is half
duplex anyhow, this probably will not change. <return to FAQ
index>
Q. What is the overall delay involved with the Internet?
The delay depends on how far the packets have to travel.
When the IRLP nodes are fairly close together, the delay is usually less
that 0.20 seconds. About the same as you experience
when talking on a digital cell phone. <return to FAQ
index>
[
06.10.2006 12:50
] Updated Антон RV3DHC
[ 06.10.2006 12:42 ] Выложено на сервер. Оригинал: http://www.irlp.net/faq.htmll
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or more RAM
