After doing this I no longer got any error. Next I show the logs.
Jan 7 21:52:15 Kamailio-Server systemd: Started Kamailio (OpenSER) - the Open Source SIP Server.
Jan 7 21:52:15 Kamailio-Server kamailio: INFO: tls [tls_init.c:503]: init_tls_compression(): disabling compression...
Jan 7 21:52:15 Kamailio-Server kamailio: Listening on
Jan 7 21:52:15 Kamailio-Server kamailio: tls:
161.35.44.66:5061Jan 7 21:52:15 Kamailio-Server kamailio: Aliases:
Jan 7 21:52:15 Kamailio-Server kamailio: tls: kamailio-server:5061
Jan 7 21:52:15 Kamailio-Server kamailio: INFO: <core> [core/tcp_main.c:4983]: init_tcp(): using epoll_lt as the io watch method (auto detected)
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_mod.c:389]: mod_init(): With ECDH-Support!
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_mod.c:392]: mod_init(): With Diffie Hellman
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_init.c:722]: tls_h_mod_init_f(): compiled with openssl version "OpenSSL 1.0.2k-fips 26 Jan 2017" (0x100020bf), kerberos support: on, compression: on
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_init.c:730]: tls_h_mod_init_f(): installed openssl library version "OpenSSL 1.0.2k-fips 26 Jan 2017" (0x100020bf), kerberos support: on, zlib compression: on#012 compiler: gcc -I. -I.. -I../include -fPIC -DOPENSSL_PIC -DZLIB -DOPENSSL_THREADS -D_REENTRANT -DDSO_DLFCN -DHAVE_DLFCN_H -DKRB5_MIT -m64 -DL_ENDIAN -Wall -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -Wa,--noexecstack -DPURIFY -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DOPENSSL_BN_ASM_MONT5 -DOPENSSL_BN_ASM_GF2m -DRC4_ASM -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DMD5_ASM -DAES_ASM -DVPAES_ASM -DBSAES_ASM -DWHIRLPOOL_ASM -DGHASH_ASM -DECP_NISTZ256_ASM
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: WARNING: tls [tls_init.c:787]: tls_h_mod_init_f(): openssl bug #1491 (crash/mem leaks on low memory) workaround enabled (on low memory tls operations will fail preemptively) with free memory thresholds 8912896 and 4456448 bytes
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: <core> [core/cfg/cfg_ctx.c:598]: cfg_set_now(): tls.low_mem_threshold1 has been changed to 8912896
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: <core> [core/cfg/cfg_ctx.c:598]: cfg_set_now(): tls.low_mem_threshold2 has been changed to 4456448
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: <core> [main.c:2834]: main(): processes (at least): 17 - shm size: 67108864 - pkg size: 4194304
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:305]: ksr_tls_fill_missing(): TLSs<default>: tls_method=22
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:317]: ksr_tls_fill_missing(): TLSs<default>: certificate='/etc/letsencrypt/live/
sbc.netvoiceperu.com/fullchain.pem'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:324]: ksr_tls_fill_missing(): TLSs<default>: ca_list='/etc/letsencrypt/live/
sbc.netvoiceperu.com/bc2025.pem'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:331]: ksr_tls_fill_missing(): TLSs<default>: crl='(null)'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:335]: ksr_tls_fill_missing(): TLSs<default>: require_certificate=1
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:342]: ksr_tls_fill_missing(): TLSs<default>: cipher_list='(null)'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:349]: ksr_tls_fill_missing(): TLSs<default>: private_key='/etc/letsencrypt/live/
sbc.netvoiceperu.com/key.pem'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:353]: ksr_tls_fill_missing(): TLSs<default>: verify_certificate=1
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:356]: ksr_tls_fill_missing(): TLSs<default>: verify_depth=9
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:359]: ksr_tls_fill_missing(): TLSs<default>: verify_client=0
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: NOTICE: tls [tls_domain.c:1107]: ksr_tls_fix_domain(): registered server_name callback handler for socket [:0], server_name='
sbc.netvoiceperu.com' ...
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:697]: set_verification(): TLSs<default>: Client MUST present valid certificate
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:305]: ksr_tls_fill_missing(): TLSc<default>: tls_method=22
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:317]: ksr_tls_fill_missing(): TLSc<default>: certificate='/etc/letsencrypt/live/
sbc.netvoiceperu.com/fullchain.pem'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:324]: ksr_tls_fill_missing(): TLSc<default>: ca_list='/etc/letsencrypt/live/
sbc.netvoiceperu.com/bc2025.pem'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:331]: ksr_tls_fill_missing(): TLSc<default>: crl='(null)'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:335]: ksr_tls_fill_missing(): TLSc<default>: require_certificate=1
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:342]: ksr_tls_fill_missing(): TLSc<default>: cipher_list='(null)'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:349]: ksr_tls_fill_missing(): TLSc<default>: private_key='/etc/letsencrypt/live/
sbc.netvoiceperu.com/key.pem'
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:353]: ksr_tls_fill_missing(): TLSc<default>: verify_certificate=1
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:356]: ksr_tls_fill_missing(): TLSc<default>: verify_depth=9
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:359]: ksr_tls_fill_missing(): TLSc<default>: verify_client=0
Jan 7 21:52:15 Kamailio-Server /usr/sbin/kamailio[29301]: INFO: tls [tls_domain.c:697]: set_verification(): TLSc<default>: Server MUST present valid certificate
Jan 7 21:52:16 Kamailio-Server /usr/sbin/kamailio[29306]: INFO: jsonrpcs [jsonrpcs_sock.c:443]: jsonrpc_dgram_process(): a new child 0/29306
Jan 7 21:52:16 Kamailio-Server /usr/sbin/kamailio[29308]: INFO: ctl [io_listener.c:214]: io_listen_loop(): io_listen_loop: using epoll_lt io watch method (config).
Also, I attach TLS communication flow between Microsoft and Kamailio (See attached image "Flow TLS Certificate"). As you can see, the TLS communication of the certificates is successful, however the SIP connection to Microsoft is still status down.
Is it possible that I have an error or I am missing a configuration parameter in the kamailio.cfg and dispatcher.list file?. Attached kamailio.cfg and dispatcher.list