AT&T PRI Keeps Going Congested

Asterisk Asterisk Support
1

I have been wrestling with this problems for over 6 weeks with absolutely no success. I am using trixbox and VicidialNOW. The PRI provider is AT&T. AT&T has done a pile of diagnostics and watched the PRI as I used trixbox and VicidialNOW. Our legacy pbx works just fine on the AT&T PRI. I have matched the settings with the legacy pbx and asterisk confs without success. Rhino, the provider for the t1 card, has gone over the appropriate settings matching what they know to work to what I have without success. I have used AT&T’s presentations from 2008’s astricon without success. Everything I do doesn’t prevent asterisk from coing congested on the pri. Congestion occurrs anywhere between 3 and 12 concurrent/nonconcurrent calls inbound, outbound, or mixture. How do I prevent the congestion?

All conf files shown are the same regardless of with asterisk based implementation is used.

zapata.conf:

;
; Zapata telephony interface
;
; Configuration file

[trunkgroups]

[channels]

language=en
context=from-zaptel
signalling=fxs_ks
rxwink=300		; Atlas seems to use long (250ms) winks
;
; Whether or not to do distinctive ring detection on FXO lines
;
;usedistinctiveringdetection=yes

usecallerid=yes
hidecallerid=no
callwaiting=yes
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
cancallforward=yes
callreturn=yes
echocancel=yes
echocancelwhenbridged=no
;echotraining=800
rxgain=0.0
txgain=0.0
group=0
callgroup=1
pickupgroup=1
immediate=no
resetinterval=1000000000
pritimer=t309,10000
pritimer=t200,1000
facilityenable=yes
transfer=yes

;faxdetect=both
faxdetect=incoming
;faxdetect=outgoing
;faxdetect=no

;Include genzaptelconf configs
#include zapata-auto.conf

group=1

;Include AMP configs
#include zapata_additional.conf

zapata-auto.conf:

; Autogenerated by /usr/sbin/genzaptelconf -- do not hand edit
; Zaptel Channels Configurations (zapata.conf)
;
; This is not intended to be a complete zapata.conf. Rather, it is intended 
; to be #include-d by /etc/zapata.conf that will include the global settings
;

; Span 1: ZTDUMMY/1 "ZTDUMMY/1 (source: RTC) 1" (MASTER) 

; Span 2: R2T1/0/1 "R2T1 (PCI) Card 0 Span 1" 
group=0,12
context=from-pstn
;switchtype = national
; note: to connect to at&t LD PRI
switchtype => 4ess
nsf=tollfreemegacom
; Overlap dialing mode (sending overlap digits)
overlapdial=yes

signalling = pri_cpe
channel => 1-23
group=
context=default

zapata-additional.conf:

;--------------------------------------------------------------------------------;
; 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       ;
;--------------------------------------------------------------------------------;
;

zaptel.conf:

# Autogenerated by /usr/sbin/genzaptelconf -- do not hand edit
# Zaptel Configuration File
#
# This file is parsed by the Zaptel Configurator, ztcfg
#

# It must be in the module loading order


# Span 1: ZTDUMMY/1 "ZTDUMMY/1 (source: RTC) 1" (MASTER) 

# Span 2: R2T1/0/1 "R2T1 (PCI) Card 0 Span 1" 
span=1,1,0,esf,b8zs
# termtype: te
bchan=1-23
dchan=24

# Global data

loadzone = us
defaultzone = us

Changes to the conf files that DO NOT solve congestion:
nsf = megacom
nsf = accunet
nsf = sdn
nsf = tollfreemegacom
signalling = pri_network (pri doesn’t work with this)
switchtype = national
resetinterval=never