Setting up a remote access site for DX Spots
A remote access site consists of a Windows machine with a
full time Internet connection, such as cable or DSL, running a software package
called BPQ32 developed by John Wiseman, G8BPQ.
A serial port on that machine is cabled to a TNC, such as a MFJ1270C,
running in KISS mode using a standard modem cable. BPQ32 creates a node with a ALIAS:CALL, such as ABCDX:N0XYZ.
Users can connect via radio to either the ALIAS or the CALL and receive a
greeting message with instructions to enter ‘DX’. Upon entering ‘DX’, BPQ32 issues a connect
request via the Internet to BPQ32 at the main site, which then automatically
connects to the DX Cluster.
There are many possible hardware configurations for Internet
access. I will only deal with the most
common two. The simplest would consist
of a single computer connected directly to the cable or dsl
modem. The more likely configuration
would consist of one or more computers on your own local area network (LAN)
created by a home router connected to the cable or dsl
modem.
In the simple configuration the first step is to determine
the IP address of your modem, which in this case is also the IP address of your
machine. You may do this by running a
task on your machine, either winipcfg.exe or ipconfig.exe. One of the two should exist on your
system. To run, go to Start/Run and to
be sure you are in the root directory enter ‘C:’, and
click OK. This will open a copy of
Windows Explorer showing the C: drive.
Now again go to Start/Run and enter ‘cmd’ or
'command'. This will open a dos like
window with a ‘c:\>’ prompt. At this prompt enter ‘winipcfg’
or ‘ipconfig’, one of the two will run (it depends
upon what OS you have).
This IP address, which I shall call the WAN IP address,
gives us some important information. RFC1597 - Address Allocation for
Private Internets reserves several ranges of addresses that are used for
private networks:
10.0.0.0 -
10.255.255.255
172.16.0.0 -
172.31.255.255
192.68.0.0 -
192.168.255.255
If your WAN IP address is within one of these ranges, then
your ISP has given you a private network address created by network
address translation (NAT). If your
address is outside of these ranges you have an address on the public
network. This information will be used
when editing the bpqaxip.cfg file.
If you use the home router configuration it is necessary to
set up the router to direct incoming UDP packets with port number 10093 to the
specific machine on which you will run BPQ32.
Assuming that you have the router properly set up so that machines on
your LAN have Internet access you will first need to determine the LAN address
of your BPQ32 machine. Follow the steps
above running ‘winipcfg or ipconfig’
to obtain this information. There are additional programming steps you would
take if you use the popular Linksys BEFSR41: As an example, let us say that you
have determined that the LAN address of the machine on which you are going to
run BPQ32 is 192.168.1.101. Using a web browser on any
machine on the LAN, open http://192.168.1.1. You may be asked for a name and
password. Unless you have programmed it
to something other than default, skip the username and go to the password box
and enter 'admin'. When it opens click
on the 'status' tab. Note the WAN IP
address. This information will be used
when editing the bpqaxip.cfg file. Now
click on 'Advanced' and when it opens click on 'Forwarding'. Under 'Ext.Port'
enter '10093 to 10093'. Check 'Protocol
UDP'. Under 'IP Address' complete
192.168.1.101, the address of the BPQ32 machine you have determined previously. Check 'Enable'. At the bottom of the page click 'Apply'.
Although you could pay extra for a fixed public IP address,
there is no need to do so. Instead visit
http://www.no-ip.com and sign up for the free dynamic IP naming service. When doing so you will be asked to choose a
prefix. A perfect choice would be your
call, for example ‘n0xzy.no-ip.com’.
They offer many other suffixes in the event the ‘no-ip.com’ suffix is
unavailable. Along with your chosen name
you will download a small program that will run on your system periodically to
communicate any changes in your public address to the DNS server at no-ip.com. There are other free dynamic naming services
as well. Search for ‘Dynamic DNS’ to
find other providers. The dynamic name
of the remote site will be used by the main site system to reach you, in lieu
of a fixed IP address.
BPQ32 software is available on the BPQ32 Yahoo Site. The software is available as an installer,
once installed an example installation for a remote outlet will be found in the
examples folder.
While many ISP’s give you a public network address, which is
a ‘real internet address,’ others will give you private network address. They do this to conserve ‘real internet
addresses’ and also to prevent you from operating a server, although they may
insist they are protecting you from hackers, which is not altogether
false. The mechanism is Network Address
Translation (NAT) and a full explanation is beyond the scope of this
article. If you receive a private
network address, your ISP has you behind NAT; you will have to periodically
‘kick the NAT box’ to keep the return path open. You do this by adding an additional parameter
“KEEPALIVE seconds” in the bpqaxip.cfg file.
The following are examples of bpqaxip.cfg, one if you have a public
address and the other if you have a private address:
# Config file for BPQAXIP (Public
IP Address version)
MHEARD
UDP 10093
MAP N5IN-3 dxspots.com UDP 10093
MAP NODES dxspots.com UDP 10093
# Config file for BPQAXIP (Private
IP Address version)
MHEARD
UDP 10093
MAP N5IN dxspots.com KEEPALIVE 120 UDP 10093
MAP NODES dxspots.com UDP 10093
In this later configuration a KEEPALIVE packet is sent to
dxspots.com after 120 seconds of no network activity to or from that
address. This special packet, which is
discarded by the other side, is sufficient to keep a return route from
dxspots.com alive in the ISP’s NAT box, without which the NAT box would send
the incoming packet to the bit bucket.
Experimentally 120 seconds was found to be frequent enough to do the
job. KEEPALIVE does generate network
activity, so it’s unfriendly to use it if you do not have to, nor to set the
time too low.
You must put your TNC in KISS mode. For a TNC2, such as a MFJ1270C, set the baud
rate to 9600, connect the device to a terminal emulator and issue the command “
When you are ready to test a connection to N5IN you should
have done the following: Having
determined if you have a public or private WAN address and based upon that you
have configured bpqaxip.cfg appropriately.
Confirm that the COM port you are using matches, including the baud
rate, within bpqcfg.txt. Compile
bpqcfg.txt into bpqcfg.bin by executing bpqcfg.exe. Now execute BPQTerminal
and let it run.
Send me an email at my obvious arrl.net address,
if it’s not obvious visit qrz.com, telling me that you have your BPQ32 node
running and give me your dynamic name (see text above concerning no-ip or whatever other dynamic naming service you have
chosen). Tell me what ALIAS:CALL you are running.
After I receive your e-mail I will check my BPQ32 node to verify that I
am receiving your nodes broadcasts. I
will then add you into my bpqcfg.txt as a locked route and edit my bpqaxip.cfg
file to provide an Internet route to you.
I may not be able to do this immediately, but I will do it as soon as
possible. If a connection can be
achieved, then your radio users upon connecting to your node can simply type DX
and be connected via UDP protocol on the Internet to my DX Cluster.
There are many more things to learn. You can for example connect to your node from
other machines on your LAN, or from another remote location. This is very convenient to verify that your
node is working without using a radio link.
Doing so will require the use of other UDP port numbers. It is best to have a UPS on your BPQ32
machine. Windows can be configured to
start from power up without the need for a password and immediately start
bpqterm.exe. I will try to document
this and some of the additional options when I have time. What I have provided so far should be
sufficient to get your ‘remote outlet’ functioning.
If any of your users
are running MFJ1270B’s or C’s, they must be told to set the parm
ACKPRIOR=OFF. The factory default is ON
and it simply does not work in a multi-user environment. Two or more MFJ users with the default
ACKPRIOR=ON will experience very unreliable operation and may even kick other
non-MFJ users off of your system. An
acceptable set of parms can be obtained by using the
RESET command to return to the factory default set. Then set ACKPRIOR=OFF. There are other parms,
which in an environment of many users may be useful, but this is the critical
one!
This document:
BPQ32_Remote_ReadMe_v2r1
2008/03/03.
Obtain the software at the BPQ32 Yahoo Site
73 de Ron N5IN