RTP трафик

Цепочка : Астериск - NAT (Mikrotik) - интернет - NAT - VoIP телефон

На микротике порты 5160 и 10000-20000 проброшены, service port SIP - отключен. Но РТП трафик в сторону VoIP телефона не идет.

Wireshark показал, что астер шлет rtp пакеты на локальный ИП VoIP телефона.

На Астериске externip и localnet указаны. Почему Астериск решает вдруг слать пакеты на локальный ип телефона?

<--- SIP read from UDP:94.BBB.CCC.DDD:1124 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 87.BBB.CCC.DDD:5160;branch=z9hG4bK4efc6710
From: "131" <sip:131@87.BBB.CCC.DDD:5160>;tag=as17b36e98
To: <sip:129@94.BBB.CCC.DDD:1124>;tag=1454414836
Call-ID: 602b9b931429ebec66556ad02233008d@87.BBB.CCC.DDD:5160
CSeq: 102 INVITE
Contact: <sip:129@94.BBB.CCC.DDD:1124>
Supported: 100rel, replaces, timer
User-Agent: Fanvil X3S/R2.2.0.3696_0c383e1a63db
Allow-Events: talk,hold
Allow: INVITE, ACK, OPTIONS, BYE, CANCEL, REFER, NOTIFY, INFO, PRACK, UPDATE, MESSAGE
Content-Type: application/sdp
Content-Length: 241

v=0
o=129 1860417920 1951922284 IN IP4 192.168.1.12
s=A conversation
c=IN IP4 192.168.1.12
t=0 0
m=audio 10008 RTP/AVP 0 8 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=sendrecv
<------------->
--- (13 headers 11 lines) ---
Found RTP audio format 0
Found RTP audio format 8
Found RTP audio format 101
Found audio description format PCMU for ID 0
Found audio description format PCMA for ID 8
Found audio description format telephone-event for ID 101
Capabilities: us - (ulaw|alaw|gsm|g726|g722), peer - audio=(ulaw|alaw)/video=(nothing)/text=(nothing), combined - (ulaw|alaw)
Non-codec capabilities (dtmf): us - 0x1 (telephone-event|), peer - 0x1 (telephone-event|), combined - 0x1 (telephone-event|)
       > 0x6041f300 -- Strict RTP learning after remote address set to: 192.168.1.12:10008
**Peer audio RTP is at port 192.168.1.12:10008**
sip_route_dump: route/path hop: <sip:129@94.BBB.CCC.DDD:1124>
set_destination: Parsing <sip:129@94.BBB.CCC.DDD:1124> for address/port to send to
set_destination: set destination to 94.BBB.CCC.DDD:1124
Transmitting (no NAT) to 94.BBB.CCC.DDD:1124:
ACK sip:129@94.BBB.CCC.DDD:1124 SIP/2.0
Via: SIP/2.0/UDP 87.BBB.CCC.DDD:5160;branch=z9hG4bK26df7106
Max-Forwards: 70
From: "131" <sip:131@87.BBB.CCC.DDD:5160>;tag=as17b36e98
To: <sip:129@94.BBB.CCC.DDD:1124>;tag=1454414836
Contact: <sip:131@87.BBB.CCC.DDD:5160>
Call-ID: 602b9b931429ebec66556ad02233008d@87.BBB.CCC.DDD:5160
CSeq: 102 ACK
User-Agent: FPBX-14.0.3.2(13.19.0)
Content-Length: 0