410P 通话中产生中断

1、卡类型 D410P
2、业务类型：回拨，在2条Pstn上建立通话
3、中断时的日志：
[Nov 23 20:53] VERBOSE[3702] logger.c: AGI Rx << EXEC Dial zap/g2/013772440872|60|RL(770000)
[Nov 23 20:53] VERBOSE[3702] logger.c: -- AGI Script Executing Application: (Dial) Options: (zap/g2/013772440872|60|RL(770000))
[Nov 23 20:53] VERBOSE[3702] logger.c: -- Setting call duration limit to 770 seconds.
[Nov 23 20:53] VERBOSE[3702] logger.c: -- Requested transfer capability: 0x00 - SPEECH
[Nov 23 20:53] VERBOSE[3702] logger.c: -- Called g2/013772440872
[Nov 23 20:53] VERBOSE[3702] logger.c: -- Zap/56-1 is proceeding passing it to Zap/51-1
[Nov 23 20:53] DEBUG[3702] chan_zap.c: Received AST_CONTROL_PROCEEDING on Zap/51-1
[Nov 23 20:53] VERBOSE[3702] logger.c: -- Zap/56-1 is ringing
[Nov 23 20:53] VERBOSE[3702] logger.c: -- Zap/56-1 answered Zap/51-1
[Nov 23 20:53] DEBUG[3702] chan_zap.c: master: 51, slave: 56, nothingok: 0
[Nov 23 20:53] DEBUG[3702] chan_zap.c: Stopping tones on 51/0 talking to 56/0
[Nov 23 20:53] DEBUG[3702] chan_zap.c: Stopping tones on 56/0 talking to 51/0
[Nov 23 20:53] DEBUG[3702] chan_zap.c: Making 56 slave to master 51 at 0
[Nov 23 20:53] DEBUG[3702] chan_zap.c: Added 70 to conference 9/51
[Nov 23 20:53] DEBUG[3702] chan_zap.c: Added 65 to conference 9/56
[Nov 23 20:53] VERBOSE[3702] logger.c: -- Native bridging Zap/51-1 and Zap/56-1
[Nov 23 21:06] DEBUG[3702] chan_zap.c: Unlinking slave 56 from 51
[Nov 23 21:06] DEBUG[3702] chan_zap.c: Removed 70 from conference 9/51
[Nov 23 21:06] DEBUG[3702] chan_zap.c: Removed 65 from conference 9/56
[Nov 23 21:06] DEBUG[3702] chan_zap.c: Set option AUDIO MODE, value: ON(1) on Zap/56-1
[Nov 23 21:06] DEBUG[3702] chan_zap.c: Not yet hungup... Calling hangup once with icause, and clearing call
[Nov 23 21:06] DEBUG[3702] chan_zap.c: Set option AUDIO MODE, value: OFF(0) on Zap/56-1
[Nov 23 21:06] VERBOSE[3702] logger.c: -- Hungup 'Zap/56-1'
问题：
为什么会产生会议？内部桥接 ？

zaptel
span=1,0,0,ccs,hdb3
bchan=1-15,17-31
dchan=16
span=2,0,0,ccs,hdb3
bchan=32-46,48-62
dchan=47
span=3,0,0,ccs,hdb3
bchan=63-77,79-93
dchan=78
span=4,0,0,ccs,hdb3
bchan=94-108,110-124
dchan=109

loadzone = us
defaultzone = us


zapata
context=callback
switchtype=euroisdn
resetinterval=never
priindication=outofband
usecallingpres=yes
signalling=pri_cpe
hidecallerid=no
usecallerid=yes
callwaiting=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
cancallforward=yes
echocancel=no
echocancelwhenbridged=no
echotraining=no
relaxdtmf=no
pridialplan = unknown
prilocaldialplan=national
callprogress=yes
callerid=asreceived
immediate=no
rxgain=0
txgain=0

;group=1
;signalling=pri_cpe
;channel => 1-15,17-31
group=2
signalling=pri_cpe
channel =>1-15,17-31,32-46,48-62
channel =>63-77,79-93,94-108,110-124

这个你得自己去检查extensions.conf,卡本身是不会干这些事的