[asterisk-dev] Asterisk / pjsip: Bug or feature? TCP/TLS connection is endless after unregistering the last trunk to the destination

[Michael Maier]

On 11.01.21 at 15:27 Joshua C. Colp wrote:
> On Mon, Jan 11, 2021 at 10:21 AM Michael Maier <m1278468 at mailbox.org> wrote:
>> It is possible to tcpkill the first connection without being restarted:
>>
>> # tcpkill -i eth0 tcp port 54761
>> [2021-01-11 14:42:15] DEBUG[8569] pjproject:        tlsc0x7fa1d82efae8 TLS
>> connection closed
>> [2021-01-11 14:42:15] DEBUG[8569] res_pjsip/pjsip_transport_events.c:
>> Reliable transport 'tlsc0x7fa1d82efae8' state:DISCONNECTED
>> [2021-01-11 14:42:15] DEBUG[8569] pjproject:           sip_transport.c
>> Transport tlsc0x7fa1d82efae8 shutting down, force=0
>> [2021-01-11 14:42:15] DEBUG[8569] res_pjsip/pjsip_transport_events.c:
>> Reliable transport 'tlsc0x7fa1d82efae8' state:SHUTDOWN
>> [2021-01-11 14:42:15] DEBUG[8569] res_pjsip/pjsip_transport_events.c:
>> Reliable transport 'tlsc0x7fa1d82efae8' state:DESTROY
>> [2021-01-11 14:42:15] DEBUG[8569] pjproject:        tlsc0x7fa1d82efae8 TLS
>> transport destroyed with reason 120104: Connection reset by peer
>>
>> If you're doing the same against Telekom, they drop the first connect
>> after 10 s (therefore no tcpkill is necessary)
>>
>> Any idea why there are 2 connections started though only one is necessary?
>> This is really odd.
>>
> 
> Nope. The code itself wasn't explicitly designed or written for this usage,
> so there may be issues with it.

Sounds like a bug to me. Anyway, I found another solution to add n standard transports listening all to no port (tested with Asterisk 18.0.1):

[estandard]
type=transport
protocol=tls
bind=0.0.0.0:0
              ^
ca_list_file=/etc/pki/tls/certs/ca-bundle.crt
method=tlsv1_2
verify_server=yes
allow_reload=no
tos=cs3
cos=3

[telekom1]
...

# netstat -tulpn | grep 5061
tcp        0      0 0.0.0.0:5061            0.0.0.0:*               LISTEN      11329/asterisk


CLI> pjsip show transports

Transport:  <TransportId........>  <Type>  <cos>  <tos>  <BindAddress....................>
==========================================================================================

Transport:  0.0.0.0-tls               tls      3    184  0.0.0.0:5061
Transport:  0.0.0.0-udp               udp      3    184  0.0.0.0:5060
Transport:  estandard                 tls      3     96  0.0.0.0:5061
Transport:  telekom1                  tls      3     96  0.0.0.0:5061
Transport:  telekom2                  tls      3     96  0.0.0.0:5061
Transport:  telekom3                  tls      3     96  0.0.0.0:5061

Using the estandard transport for easybell works fine and doesn't start two connections to the ISP at startup.

Hope that works for my other trunks as expected.


Thanks
Michael