Почему Нету аудио в исходящих звонках через SCCP?

Доброго времени суток!
Настроил SCCP телефоны Cisco Ip Phone 7942 с помощью chan_sccp Asterisk в FreePBX, но есть проблема:
Можно звонить и звонки проходят и принимаются, но нету исходящего звука, т е я слышу, но меня не слышит. В чем может проблема?

sccp.conf:

[general]
servername = FreePbxSCCP
keepalive = 60
debug = 1
context = from-internal-xfer
dateformat = D.M.Y
bindaddr = 192.168.1.30
port = 2000
disallow=all
allow=alaw
allow=ulaw
firstdigittimeout = 16
digittimeout = 8
autoanswer_ring_time = 1
autoanswer_tone = 0x32
remotehangup_tone = 0x32
transfer_tone = 0
callwaiting_tone = 0x2d
musicclass=default
language=en
nat=off
deny=0.0.0.0/0.0.0.0
permit=internal                                     
permit=192.168.1.0/255.255.255.0
permit=0.0.0.0/0.0.0.0
dndFeature = on
sccp_tos = 0x68
sccp_cos = 4
audio_tos = 0xB8
audio_cos = 6
video_tos = 0x88
video_cos = 5
echocancel = on
silencesuppression = off
private = on
callanswerorder=oldestfirst
hotline_enabled=yes                                   
hotline_context=default                               
hotline_extension=111

[SEP58XXXXXXXD7]

description = none

devicetype = 7942

type = device

button = line, 128

deny=0.0.0.0/0.0.0.0

permit=0.0.0.0/0.0.0.0

pickupcontext = sccp

tzoffset = +0

transfer = on

trustphoneip = no

directrtp=off

earlyrtp = progress

private = on

mwilamp = on

mwioncall = off

setvar=testvar=value

cfwdall = on


[128]

id = 128

type = line

label = Phone 128

description = Line 128

cid_name = 128

cid_num = 128

echocancel = off

context = from-internal-xfer

incominglimit = 3

transfer = on

vmnum = 600

trnsfvm = 1000

secondary_dialtone_digits = 9

secondary_dialtone_tone = 0x22

musicclass=default

language=en

echocancel = on

silencesuppression = off