со стороны м200 до медианта все норм...
вот что лог выдал при исходящем вызове.
-- Called SIP/984959210110@mediant
<--- SIP read from UDP:192.168.18.196:5060 --->
SIP/2.0 100 Trying
Via: SIP/2.0/UDP 192.168.18.85:5060;branch=z9hG4bK7a68a45c
From: "101" <sip:3015551005@192.168.18.196>;tag=as0ecfb369
To: <sip:984959210110@192.168.18.196:5060>;tag=1c1864463559
Call-ID: 7ed5e66f4f3ec206541fdf7019930335@192.168.18.196
CSeq: 102 INVITE
Supported: em,timer,replaces,path,resource-priority
Allow: REGISTER,OPTIONS,INVITE,ACK,CANCEL,BYE,NOTIFY,PRACK,REFER,INFO,SUBSCRIBE,UPDATE
Server: Audiocodes-Sip-Gateway-Mediant 2000/v.5.60A.027.002
Content-Length: 0
<------------->
--- (10 headers 0 lines) ---
<--- SIP read from UDP:192.168.18.196:5060 --->
SIP/2.0 404 Not Found
Via: SIP/2.0/UDP 192.168.18.85:5060;branch=z9hG4bK7a68a45c
From: "101" <sip:3015551005@192.168.18.196>;tag=as0ecfb369
To: <sip:984959210110@192.168.18.196:5060>;tag=1c1864463559
Call-ID: 7ed5e66f4f3ec206541fdf7019930335@192.168.18.196
CSeq: 102 INVITE
Supported: em,timer,replaces,path,resource-priority
Allow: REGISTER,OPTIONS,INVITE,ACK,CANCEL,BYE,NOTIFY,PRACK,REFER,INFO,SUBSCRIBE,UPDATE
Server: Audiocodes-Sip-Gateway-Mediant 2000/v.5.60A.027.002
Reason: Q.850 ;cause=1
Content-Length: 0
<------------->
--- (11 headers 0 lines) ---
Transmitting (no NAT) to 192.168.18.196:5060:
ACK sip:984959210110@192.168.18.196:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.18.85:5060;branch=z9hG4bK7a68a45c
Max-Forwards: 70
From: "101" <sip:3015551005@192.168.18.196>;tag=as0ecfb369
To: <sip:984959210110@192.168.18.196:5060>;tag=1c1864463559
Contact: <sip:3015551005@192.168.18.85:5060>
Call-ID: 7ed5e66f4f3ec206541fdf7019930335@192.168.18.196
CSeq: 102 ACK
User-Agent: asterisk_DTS
Content-Length: 0
---
-- SIP/mediant-00000042 is circuit-busy
== Everyone is busy/congested at this time (1:0/1/0)
-- Executing [984959210110@101:2] Hangup("SIP/101-00000041", "") in new stack
== Spawn extension (101, 984959210110, 2) exited non-zero on 'SIP/101-00000041'