Задержка в меню IVR

Доброго времени суток! Начали создавать IVR и столкнулись с проблемой: при переходе на одно из меню появляется 4-секундная задержка. Что интересно, это проявляется только на одном пункте меню и на возврате в главное меню. Сначала предположили, что проблема может быть со звуковым файлом или его проигрыванием, поменяли местами звуковые файлы двух пунктов меню (проблемном и нормальном), проблема не переместилась на изначально нормальный пункт меню, следовательно, проблема не со звуковым файлом.

Конфиг самого IVR (проблемный пункт меню - voicemenu-custom-9):

[default]
include => sccp_phones
exten => 111,1,Answer()
exten => 111,2,Playback(demo-echotest)
exten => 111,3,Echo()
exten => 111,4,Playback(demo-echodone)
exten => 111,5,Playback(vm-goodbye)
exten => 111,6,Hangup()
exten = _#6XXX,1,Set(MBOX=${EXTEN:1}@default)
exten = _#6XXX,n,VoiceMail(${MBOX})
exten = a,1,VoicemailMain(${MBOX})
exten = 8888,1,VoiceMailMain(${CALLERID(num)}@default)

[voicemenu-custom-8]
include = default
exten = s,1,NoOp(ivrWelcome)
exten = s,2,Answer()
exten = s,3,Background(record/ivrWelcome)
exten = s,4,WaitExten(5)
exten = s,5,Queue(6503,twn,,,)
exten = s,6,Queue(6505,twn,,,)
exten = s,7,Queue(6504,twn,,,)
exten = s,8,Playback(record/ivrSorry)
exten = s,9,VoiceMail(6001@default&6002@default&6003@default,s)
exten = s,10,Hangup()
exten = 0,1,Goto(voicemenu-custom-13,s,1)
exten = 1,1,Goto(voicemenu-custom-9,s,1)
exten = 2,1,Goto(voicemenu-custom-10,s,1)
exten = 3,1,Goto(voicemenu-custom-11,s,1)
exten = 4,1,Goto(voicemenu-custom-12,s,1)
exten = 5,1,Goto(voicemenu-custom-14,s,1)
exten = t,1,Goto(voicemenu-custom-13,s,1)

[voicemenu-custom-9]
include = default
exten = s,1,NoOp(ivrItem1)
exten = s,2,Background(record/ivrItem1)
exten = s,3,WaitExten(2)
exten = s,4,Queue(6503,twn,,,)
exten = s,5,Queue(6505,twn,,,)
exten = s,6,Queue(6504,twn,,,)
exten = s,7,VoiceMail(6001@default&6002@default&6003@default,s)
exten = s,8,Hangup()
exten = 1,1,Goto(voicemenu-custom-8,s,1)

[voicemenu-custom-10]
include = default
exten = s,1,NoOp(ivrItem2)
exten = s,2,Background(record/ivrItem2)
exten = s,3,WaitExten(2)
exten = s,4,Queue(6506,twn,,,)
exten = s,5,Queue(6503,twn,,,)
exten = s,6,Queue(6505,twn,,,)
exten = s,7,VoiceMail(6001@default&6002@default&6003@default,s)
exten = s,8,Hangup()
exten = 1,1,Goto(voicemenu-custom-8,s,1)

[voicemenu-custom-11]
include = default
exten = s,1,NoOp(ivrItem3)
exten = s,2,Background(record/ivrItem3)
exten = s,3,WaitExten(2)
exten = s,4,Queue(6501,twn,,,)
exten = s,5,Hangup()
exten = 1,1,Goto(voicemenu-custom-8,s,1)

[voicemenu-custom-12]
include = default
exten = s,1,NoOp(ivrItem4)
exten = s,2,Background(record/ivrItem4)
exten = s,3,WaitExten(2)
exten = s,4,Hangup()
exten = 1,1,Goto(voicemenu-custom-8,s,1)

[voicemenu-custom-14]
include = default
exten = s,1,NoOp(ivrItem5)
exten = s,2,Queue(6506,twn,,,)
exten = s,3,Queue(6503,twn,,,)
exten = s,4,Queue(6505,twn,,,)
exten = s,5,VoiceMail(6001@default&6002@default&6003@default,s)
exten = s,6,Hangup()

[voicemenu-custom-13]
include = default
exten = s,1,NoOp(ivrDefault)
exten = s,2,Queue(6503,twn,,,)
exten = s,3,Queue(6505,twn,,,)
exten = s,4,Queue(6504,twn,,,)
exten = s,5,VoiceMail(6001@default&6002@default&6003@default,s)
exten = s,6,Hangup()

Логи core set debug 5:

[Oct 20 17:03:48] DEBUG[4102][C-00000002]: res_rtp_asterisk.c:2852 create_dtmf_frame: Creating BEGIN DTMF Frame: 50 (2), at 10.10.10.113:2736
[Oct 20 17:03:48] DTMF[4102][C-00000002]: channel.c:4170 __ast_read: DTMF begin '2' received on SIP/stc2800022-00000001
[Oct 20 17:03:48] DTMF[4102][C-00000002]: channel.c:4174 __ast_read: DTMF begin ignored '2' on SIP/stc2800022-00000001
[Oct 20 17:03:48] DEBUG[4102][C-00000002]: res_rtp_asterisk.c:2852 create_dtmf_frame: Creating END DTMF Frame: 50 (2), at 10.10.10.113:2736
[Oct 20 17:03:48] DTMF[4102][C-00000002]: channel.c:4084 __ast_read: DTMF end '2' received on SIP/stc2800022-00000001, duration 181 ms
[Oct 20 17:03:48] DTMF[4102][C-00000002]: channel.c:4154 __ast_read: DTMF end passthrough '2' on SIP/stc2800022-00000001
[Oct 20 17:03:48] DEBUG[4102][C-00000002]: channel.c:3577 ast_settimeout: Scheduling timer at (0 requested / 0 actual) timer ticks per second
[Oct 20 17:03:48] DEBUG[4102][C-00000002]: channel.c:3577 ast_settimeout: Scheduling timer at (0 requested / 0 actual) timer ticks per second
[Oct 20 17:03:48] DEBUG[4102][C-00000002]: channel.c:5361 set_format: Set channel SIP/stc2800022-00000001 to write format alaw
[Oct 20 17:03:48] DEBUG[4102][C-00000002]: pbx.c:4890 pbx_extension_helper: Launching 'Goto'
[Oct 20 17:03:48] DEBUG[4102][C-00000002]: pbx.c:4890 pbx_extension_helper: Launching 'BackGround'
[Oct 20 17:03:48] DEBUG[4102][C-00000002]: channel.c:5361 set_format: Set channel SIP/stc2800022-00000001 to write format slin
[Oct 20 17:03:48] DEBUG[4102][C-00000002]: channel.c:3577 ast_settimeout: Scheduling timer at (50 requested / 50 actual) timer ticks per second

[Oct 20 17:03:49] DEBUG[4102][C-00000002]: res_rtp_asterisk.c:2852 create_dtmf_frame: Creating BEGIN DTMF Frame: 49 (1), at 10.10.10.113:2736
[Oct 20 17:03:49] DTMF[4102][C-00000002]: channel.c:4170 __ast_read: DTMF begin '1' received on SIP/stc2800022-00000001
[Oct 20 17:03:49] DTMF[4102][C-00000002]: channel.c:4174 __ast_read: DTMF begin ignored '1' on SIP/stc2800022-00000001
[Oct 20 17:03:50] DEBUG[4102][C-00000002]: res_rtp_asterisk.c:2852 create_dtmf_frame: Creating END DTMF Frame: 49 (1), at 10.10.10.113:2736
[Oct 20 17:03:50] DTMF[4102][C-00000002]: channel.c:4084 __ast_read: DTMF end '1' received on SIP/stc2800022-00000001, duration 541 ms
[Oct 20 17:03:50] DTMF[4102][C-00000002]: channel.c:4154 __ast_read: DTMF end passthrough '1' on SIP/stc2800022-00000001
[Oct 20 17:03:50] DEBUG[4102][C-00000002]: channel.c:3577 ast_settimeout: Scheduling timer at (0 requested / 0 actual) timer ticks per second
[Oct 20 17:03:50] DEBUG[4102][C-00000002]: channel.c:3577 ast_settimeout: Scheduling timer at (0 requested / 0 actual) timer ticks per second
[Oct 20 17:03:50] DEBUG[4102][C-00000002]: channel.c:5361 set_format: Set channel SIP/stc2800022-00000001 to write format alaw
[Oct 20 17:03:50] DEBUG[4102][C-00000002]: pbx.c:6555 __ast_pbx_run: Oooh, got something to jump out with ('1')!
[Oct 20 17:03:52] DEBUG[4102][C-00000002]: res_rtp_asterisk.c:3184 ast_rtcp_read: Got RTCP report of 128 bytes
[Oct 20 17:03:52] DEBUG[4102][C-00000002]: res_rtp_asterisk.c:3410 ast_rtcp_read: Unknown RTCP packet (pt=207) received from 10.10.10.113:2737
[Oct 20 17:03:55] DEBUG[4102][C-00000002]: pbx.c:4890 pbx_extension_helper: Launching 'Goto'
[Oct 20 17:03:55] DEBUG[4102][C-00000002]: channel.c:5361 set_format: Set channel SIP/stc2800022-00000001 to write format slin
[Oct 20 17:03:55] DEBUG[4102][C-00000002]: res_rtp_asterisk.c:2521 ast_rtp_raw_write: Difference is 39992, ms is 5019
[Oct 20 17:03:55] DEBUG[4102][C-00000002]: channel.c:3577 ast_settimeout: Scheduling timer at (50 requested / 50 actual) timer ticks per second

В логах смущает строка:

[Oct 20 17:03:50] DEBUG[4102][C-00000002]: pbx.c:6555 __ast_pbx_run: Oooh, got something to jump out with ('1')!

Но, увы, пока не столько опыта, чтобы самостоятельно разобраться с этим. Да и гугл не особо помог. Может кто подскажет, в чем может быть беда?