Skip navigation.
The fusion of 2-way radio systems and VOIP

Interfacing to TheLinkBox Program

It is possible to interface an app_rpt installation with TheLinkBox Program (by Skip, WB6YMH), using the chan_tlb channel driver.

The connection(s) are accessed and referred to by a locally-assigned (private) node number, staring
with '1' (generally 1000-1999, as are any nodes not in the 'public' numbering space). Since the interface
is unique to the app_rpt installation, other app_rpt stations must first connect to the app_rpt node(s)
configured to connect with the desired TheLinkBox station(s).

Both TheLinkBox and app_rpt sides of the connection must choose a consecutive pair of UDP port numbers
on which to communicate (ports 44966/44967 typically) and also must both be on static IP addresses.

TheLinkBox supports the codecs ULAW, G726 and GSM. The app_rpt side of the connection dictates which
codec is to be used.

To enable TheLinkBox connectivity, there must be a file /etc/asterisk/tlb.conf specified as

call=WB6NIL-R           ; Call of the app_rpt station
port=44966              ; Start of UDP port range (this port, port + 1)
astnode=2008            ; app_rpt node associated with this instance (for incoming connections)
context=radio-secure    ; Asterisk context for incoming connections
codec=ULAW              ; Default CODEC to be used

1001 = W6ABC,,44966      ; This one is for W6ABC at ip default CODEC
1002 = W1XYZ,,1234,G726  ; This one is for W1XYZ at ip with G726 CODEC

You can, if you wish, have multiple instances under different sections (such as [tlb1], etc)
as long as they are on different UDP port pairs.

NOTE: The UDP port pair must start with an even port number. The even port is for the RTP (audio)
and the odd port is for the RTCP (control/supervisory).

On TheLinkBox side, you must specify the following in the main configuration file (generally

RTP_Port = 44966

And you must have an entry if your ACL file (generally tlb.acl) for each app_rpt node as follows:

allow   WB6NIL     -       -R

This particular example would allow station WB6NIL-R access from ip

NOTE: You must be running at least version 0.47 of TheLinkBox to use this feature.

Recent comments