Error to connect a PBX central "Intelbras Impacta" in Asterisk PJSIP

The Asterisk is loggin it in logger debug mode.

Can anyone help to interpret why happen?

<--- Received SIP request (445 bytes) from UDP: --->
From: 19009001<>;tag=LKXf2-tR4f
To: 19009001<>
Via: SIP/2.0/UDP;branch=z9hG4bKrE0f2-JiTzHd*M
Contact: 19009001<sip:19009001@>
Max-Forwards: 70
User-Agent: INTELBRAS IMPACTA -  Jun 20 2013
Expires: 90
Content-Length: 0

<--- Transmitting SIP response (543 bytes) to UDP: --->
SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP;rport=5060;received=;branch=z9hG4bKrE0f2-JiTzHd*M
From: "19009001" <>;tag=LKXf2-tR4f
To: "19009001" <>;tag=z9hG4bKrE0f2-JiTzHd*M
WWW-Authenticate: Digest  realm="asterisk",nonce="1547832217/55c6066a3dcf680d4d0fc971329f1eb4",opaque="50c750ed3cb9929d",algorithm=md5,qop="auth"
Server: Asterisk PBX 13.21.1
Content-Length:  0

Because you have receive a well formed REGISTER request. Your trace is n normal but incomplete. The system that issued the REGISTER should repeat the request, but this time with authentication data.

but this endpoint is always logging it

Turn off the protocol logging.

well, the endpoint is not connect in the server, if i I do that I can’t see nothing to try solve the issue.

I made news tests and checked that the PBX is connecting with others PBX server but not in mine.

Is it too weird, I am using Asterisk 13.21.1 and PJSIP 2.7.2 anyone think upgrade version will solve it?

Now looks like the port of the packet is not changed as when I reported this issue.

regards, Leandro