Asterisk. Конфигурационный файл udptl.conf.

Этот файл используется для конфигурации в Asterisk поддержки пакетов UDPTL (User Datagram Protocol Transport Level – протокол транспортного уровня для передачи UDP-данных через пакетные сети).
UDPTL-пакеты – один из транспортов, используемых при передаче факсимильных сообщений по протоколу T.38 по IP-соединениям.

Пример файла:
;--------------------------------------------------------------------------------;
; Do NOT edit this file as it is auto-generated by FreePBX. All modifications to ;
; this file must be done via the web gui. There are alternative files to make ;
; custom modifications, details at: http://freepbx.org/configuration_files ;
;--------------------------------------------------------------------------------;
;
; This file is part of FreePBX.
;
; FreePBX is free software: you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation, either version 2 of the License, or
; (at your option) any later version.
;
; FreePBX is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with FreePBX. If not, see .
;
; Copyright (C) 2013 Schmooze Com, Inc

;
; UDPTL Configuration (UDPTL is one of the transports for T.38)
;
; NOTICE: Currently not including this file can result in Asterisk terminating.
; There is no support yet for configuring this in FreePBX, that
; functionality will come in the future when needed. The following are
; the default settings. Changes should be made in the custom file.
;
; DEFAULTS:
;
; UDPTL start and UDPTL end configure start and end addresses
;
; udptlstart=4000
; udptlend=4999
;
; Whether to enable or disable UDP checksums on UDPTL traffic
;
; udptlchecksums=no
;
; The number of error correction entries in a UDPTL packet
;
; udptlfecentries = 3
;
; The span over which parity is calculated for FEC in a UDPTL packet
;
; udptlfecspan = 3
;
; Some VoIP providers will only accept an offer with an even-numbered
; UDPTL port. Set this option so that Asterisk will only attempt to use
; even-numbered ports when negotiating T.38. Default is no.
;
; use_even_ports = no