i had configured voicemail, here is the config files voicemail.conf, sip.conf, extensions.conf, zaptel.conf, zapata.conf



voice mail is working when ever call is received, extension 2000 receives it and if not answered in 20 secs, message is stored in 
voicemail no problem in that. after creating voice mail if some one again call at that no this time even bell dosent ring, busy 
tone is heard, but when i restart machine call can be rceived in extension 2000, but as soon voicemail is created after 20 secs,
same problem than no one can call at that no,again  gives busy tone.




###################################################################################

[root@localhost ~]# vi /etc/asterisk/voicemail.conf
[general]
format = wav
attach = yes

[default]
; Syntax for new entries looks like this:
; MailboxNumber => password,name,e-mail,pager,options
; (usually, the MailboxNumber is the same as the Extension)
2000 => 1234,abc,abc@abc.com
2001 => 1234,def,def@def.com


#############################################################################################

sip.conf

[general]
port = 5060
bindaddr = 0.0.0.0
context = others

[2000]
type=friend
context=voicemail
secret=1234
host=dynamic

[2001]
type=friend
context=voicemail
secret=1234
host=dynamic

#########################################################################################

vi /extensions.conf

[root@localhost ~]# vi /etc/asterisk/extensions.conf
[from-zaptel]; plz check zapata.conf
exten => s,1,wait(2)
exten => s,n,Goto(voicemail,2000,1)


[voicemail]
exten => 2000,1,Dial(SIP/2000,20)
exten => 2000,2,VoiceMail(2000,u)

exten => 2999,1,VoiceMailMain(${CALLERID(num)},s)


#########################################################################################

vi zaptel.conf

#autogenerated by /usr/sbin/wancfg_zaptel do not hand edit
#autogenrated on 2010-02-09
#Zaptel Channels Configurations
#For detailed Zaptel options, view /etc/zaptel.conf.bak
loadzone=us
defaultzone=us


#Sangoma USB U100  [bus:2-3 span:1] <wanpipe1>
fxsks=1
fxsks=2

###########################################################################################

vi zapata.conf

;autogenerated by /usr/sbin/wancfg_zaptel do not hand edit
;autogenrated on 2010-02-09
;Zaptel Channels Configurations
;For detailed Zaptel options, view /etc/asterisk/zapata.conf.bak

[trunkgroups]

[channels]
context=default
usecallerid=yes
hidecallerid=no
callwaiting=yes
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
canpark=yes
cancallforward=yes
callreturn=yes
echocancel=yes
echocancelwhenbridged=yes
relaxdtmf=yes
rxgain=0.0
txgain=0.0
group=1
callgroup=1
pickupgroup=1
immediate=no


;Sangoma AU100 [slot:0 bus: span:1]  <wanpipe1>
context=from-zaptel
group=0
signalling = fxs_ks
channel => 1

context=from-zaptel
group=0
signalling = fxs_ks
channel => 2

#########################################################################################