swg2008 Status: 401 Unauthorized ---> Grandstream UCM 6202

Hi everyone.
The gateway SWG2008 acts as a server. A call from the mobile network is received successfully, but then comes the busy answer from the Grandstream UCM 6202.
Sip trunk registration is successful.
Gateway settings, gsm packet capture and settings UCM in the attachment.
Also in the attachment of the sip logs from the gateway.
The incoming route to UCM is configured as _X.
Help solve the problem.

Hello Sir，

Check from the sip logs here

INVITE sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.88.38:5060;branch=z9hG4bK40fef819;rport
Max-Forwards: 70
From: "+380636321478" <sip:[email protected]>;tag=as6b47db27
To: <sip:[email protected]:5060>
Contact: <sip:[email protected]:5060>
Call-ID: [email protected]:5060
CSeq: 102 INVITE
User-Agent: VoxStack Wireless Gateway
Date: Fri, 08 Nov 2019 09:41:22 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH
Supported: replaces, timer
Content-Type: application/sdp
Content-Length: 386

v=0
o=- 1352992407 1352992407 IN IP4 192.168.88.38
s=VoxStack Wireless Gateway
c=IN IP4 192.168.88.38
t=0 0
m=audio 12394 RTP/AVP 8 0 3 9 4 111 101
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:3 GSM/8000
a=rtpmap:9 G722/8000
a=rtpmap:4 G723/8000
a=fmtp:4 annexa=no
a=rtpmap:111 G726-32/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16
a=ptime:20
a=sendrecv

---

<--- SIP read from UDP:192.168.88.2:5060 --->
SIP/2.0 404 Not Found
Via: SIP/2.0/UDP 192.168.88.38:5060;rport=5060;received=192.168.88.38;branch=z9hG4bK40fef819
Call-ID: [email protected]:5060
From: "+380636321478" <sip:[email protected]>;tag=as6b47db27
To: <sip:U[email protected]>;tag=3eb71305-9f57-4b9b-85f5-b6e6efb025dc
CSeq: 102 INVITE
Server: Grandstream UCM6202V1.5A 1.0.19.27
Content-Length: 0


Your PBX side send 404 message , So you need to check the PBX side settings .