First example is good.

REGISTER 11 headers, 0 lines
Reliably Transmitting (no NAT) to 321.654.987.9:5061:
REGISTER sip:server.voice.provider.net:5061 SIP/2.0
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK268dfe47;rport
Max-Forwards: 70
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as56155888
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 110 REGISTER
User-Agent: John Covert Private Household SIP Service
Expires: 120
Contact: <sip:95555@123.456.789.0>
Content-Length: 0


---
Really destroying SIP dialog '0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld' Method: REGISTER
asterisk*CLI> 
<--- SIP read from UDP:321.654.987.9:5061 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK268dfe47;rport
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as56155888
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 110 REGISTER
Contact: <sip:95555@123.456.789.0>;expires=20
Content-Length: 0


<------------->
--- (8 headers 0 lines) ---
Scheduling destruction of SIP dialog '0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld' in 32000 ms (Method: REGISTER)
[May  6 12:11:45] NOTICE[7563]: chan_sip.c:18186 handle_response_register: Outbound Registration: Expiry for server.voice.provider.net is 20 sec (Scheduling reregistration in 16 s)


----------------------------------------
Second example requires six retries before acceptance.

[May  6 12:12:33] NOTICE[7563]: chan_sip.c:11464 sip_reregister:    -- Re-registration for  1NPANXXXXXX@server.voice.provider.net
REGISTER 11 headers, 0 lines
Reliably Transmitting (no NAT) to 321.654.987.9:5061:
REGISTER sip:server.voice.provider.net:5061 SIP/2.0
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
Max-Forwards: 70
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
User-Agent: John Covert Private Household SIP Service
Expires: 120
Contact: <sip:95555@123.456.789.0>
Content-Length: 0


---
asterisk*CLI> 
<--- SIP read from UDP:321.654.987.9:5061 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
Contact: <sip:95555@123.456.789.0>;expires=20
Content-Length: 0


<------------->
--- (8 headers 0 lines) ---
Retransmitting #1 (no NAT) to 321.654.987.9:5061:
REGISTER sip:server.voice.provider.net:5061 SIP/2.0
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
Max-Forwards: 70
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
User-Agent: John Covert Private Household SIP Service
Expires: 120
Contact: <sip:95555@123.456.789.0>
Content-Length: 0


---
asterisk*CLI> 
<--- SIP read from UDP:321.654.987.9:5061 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
Contact: <sip:95555@123.456.789.0>;expires=20
Content-Length: 0


<------------->
--- (8 headers 0 lines) ---
Retransmitting #2 (no NAT) to 321.654.987.9:5061:
REGISTER sip:server.voice.provider.net:5061 SIP/2.0
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
Max-Forwards: 70
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
User-Agent: John Covert Private Household SIP Service
Expires: 120
Contact: <sip:95555@123.456.789.0>
Content-Length: 0


---
asterisk*CLI> 
<--- SIP read from UDP:321.654.987.9:5061 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
Contact: <sip:95555@123.456.789.0>;expires=20
Content-Length: 0


<------------->
--- (8 headers 0 lines) ---
Retransmitting #3 (no NAT) to 321.654.987.9:5061:
REGISTER sip:server.voice.provider.net:5061 SIP/2.0
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
Max-Forwards: 70
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
User-Agent: John Covert Private Household SIP Service
Expires: 120
Contact: <sip:95555@123.456.789.0>
Content-Length: 0


---
asterisk*CLI> 
<--- SIP read from UDP:321.654.987.9:5061 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
Contact: <sip:95555@123.456.789.0>;expires=20
Content-Length: 0


<------------->
--- (8 headers 0 lines) ---
Retransmitting #4 (no NAT) to 321.654.987.9:5061:
REGISTER sip:server.voice.provider.net:5061 SIP/2.0
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
Max-Forwards: 70
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
User-Agent: John Covert Private Household SIP Service
Expires: 120
Contact: <sip:95555@123.456.789.0>
Content-Length: 0


---
asterisk*CLI> 
<--- SIP read from UDP:321.654.987.9:5061 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
Contact: <sip:95555@123.456.789.0>;expires=20
Content-Length: 0


<------------->
--- (8 headers 0 lines) ---
Retransmitting #5 (no NAT) to 321.654.987.9:5061:
REGISTER sip:server.voice.provider.net:5061 SIP/2.0
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
Max-Forwards: 70
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
User-Agent: John Covert Private Household SIP Service
Expires: 120
Contact: <sip:95555@123.456.789.0>
Content-Length: 0


---
asterisk*CLI> 
<--- SIP read from UDP:321.654.987.9:5061 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
Contact: <sip:95555@123.456.789.0>;expires=20
Content-Length: 0


<------------->
--- (8 headers 0 lines) ---
Really destroying SIP dialog '0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld' Method: REGISTER
Retransmitting #6 (no NAT) to 321.654.987.9:5061:
REGISTER sip:server.voice.provider.net:5061 SIP/2.0
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
Max-Forwards: 70
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
User-Agent: John Covert Private Household SIP Service
Expires: 120
Contact: <sip:95555@123.456.789.0>
Content-Length: 0


---
asterisk*CLI> 
<--- SIP read from UDP:321.654.987.9:5061 --->
SIP/2.0 200 OK
Via: SIP/2.0/UDP 123.456.789.0:5060;branch=z9hG4bK1769b8ed;rport
From: <sip:1NPANXXXXXX@server.voice.provider.net>;tag=as4f92267d
To: <sip:1NPANXXXXXX@server.voice.provider.net>
Call-ID: 0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld
CSeq: 112 REGISTER
Contact: <sip:95555@123.456.789.0>;expires=20
Content-Length: 0


<------------->
--- (8 headers 0 lines) ---
Scheduling destruction of SIP dialog '0da81b0e15814adc50ce5dd05d3f7fd1@sip.mydomain.tld' in 32000 ms (Method: REGISTER)
[May  6 12:12:49] NOTICE[7563]: chan_sip.c:18186 handle_response_register: Outbound Registration: Expiry for server.voice.provider.net is 20 sec (Scheduling reregistration in 16 s)

---------------------------------------------------------------