Please check the links: https://www.kamailio.org/wiki/cookbooks/devel/core#fork https://www.kamailio.org/wiki/cookbooks/devel/core#log_stderror Your issue was related to fork. The stderr setting was just for convenience (log via syslog instead of polluting the terminal). If the documentation is not clear, let us know and we will improve it. -ovidiu On Thu, Jun 17, 2021 at 6:02 PM Peter Manley &lt;peter.manley(a)kombea.com&gt; wrote: > > Hello Ovidiu, > > > > Interestingly, that fixed the problem. I can now continue to make progress. > > > > Why does not forking and/or logging to stderr cause this to happen? > > > > Thank you! > > > > Regards, > > > > Peter Manley > > > > > > Ovidiu Sas osas at voipembedded.com > Thu Jun 17 23:05:14 CEST 2021 > > Previous message (by thread): [SR-Users] Unable to establish TCP connection with Kamailio > Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] > > ________________________________ > > It seems that you have fork set to no, > > Let kamailio fork and collect logs via syslog (not via stderror). > > > > -ovidiu > > > > > > On Thu, Jun 17, 2021 at 16:26 Peter Manley <peter.manley at kombea.com> wrote: > > > > > Hello, > > > > > > > > > > > > I’m running Kamailio Version 5.3.2 on Ubuntu 20.04. Here my build > > > information: > > > > > > > > > > > > version: kamailio 5.3.2 (x86_64/linux) > > > > > > flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, > > > DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, > > > F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, > > > USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, > > > HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED > > > > > > ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, > > > BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB > > > > > > poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. > > > > > > id: unknown > > > > > > compiled with gcc 9.2.1 > > > > > > > > > > > > I have the following configuration set in my kamalio.cfg file: > > > > > > > > > > > > ##!define WITH_MYSQL > > > > > > ##!define WITH_AUTH > > > > > > ##!define WITH_USRLOCDB > > > > > > ##!define WITH_TLS > > > > > > ##!define WITH_HOMER > > > > > > ##!define WITH_WEBSOCKETS > > > > > > ##!define WITH_ANTIFLOOD > > > > > > ##!define WITH_IPV6 > > > > > > ##!define WITH_BRIDGE_ON_FAIL > > > > > > ##!define WITH_LOCALHOST_WS > > > > > > ##!define WITH_LOCALHOST_SIP > > > > > > > > > > > > #!substdef "!MY_SIP_PORT!5060!g" > > > > > > #!substdef "!MY_SIPS_PORT!5061!g" > > > > > > #!substdef "!MY_WS_PORT!8088!g" > > > > > > #!substdef "!MY_WSS_PORT!8089!g" > > > > > > > > > > > > #!substdef "!MY_LOG_FACILITY!LOG_DAEMON!g" > > > > > > > > > > > > #!substdef "!MY_IP4_ADDR!172.16.0.57!g" > > > > > > #!substdef "!IP4_LOCALHOST!127.0.0.1!g" > > > > > > #!substdef "!MY_WS4_ADDR!tcp:MY_IP4_ADDR:MY_WS_PORT!g" > > > > > > #!substdef "!MY_WSS4_ADDR!tls:MY_IP4_ADDR:MY_WSS_PORT!g" > > > > > > #!substdef "!LOCALHOST_WS4_ADDR!tcp:IP4_LOCALHOST:MY_WS_PORT!g" > > > > > > #!substdef "!LOCALHOST_WSS4_ADDR!tls:IP4_LOCALHOST:MY_WSS_PORT!g" > > > > > > > > > > > > #!ifdef WITH_IPV6 > > > > > > #!substdef "!MY_IP6_ADDR![fe80::d6e4:2f5f:e5b7:7dff]!g" > > > > > > #!substdef "!IP6_LOCALHOST![::1]!g" > > > > > > #!substdef "!MY_WS6_ADDR!tcp:MY_IP6_ADDR:MY_WS_PORT!g" > > > > > > #!substdef "!MY_WSS6_ADDR!tls:MY_IP6_ADDR:MY_WSS_PORT!g" > > > > > > #!substdef "!LOCALHOST_WS6_ADDR!tcp:IP6_LOCALHOST:MY_WS_PORT!g" > > > > > > #!substdef "!LOCALHOST_WSS6_ADDR!tls:IP6_LOCALHOST:MY_WSS_PORT!g" > > > > > > #!endif > > > > > > > > > > > > #!substdef "!MY_DOMAIN!rtpengine.kombea.io!g" > > > > > > debug=10 // debug level (cmd line: -dddddddddd) > > > > > > children=4 > > > > > > #fork=yes > > > > > > force_rport=yes // Add recieved port to VIA > > > > > > #log_stderror=no // (cmd line: -E) > > > > > > > > > > > > // Uncomment these lines to enter debugging mode > > > > > > fork=no > > > > > > log_stderror=yes > > > > > > > > > > > > check_via=no // (cmd. line: -v) > > > > > > dns=no // (cmd. line: -r) > > > > > > rev_dns=no // (cmd. line: -R) > > > > > > > > > > > > log_facility=MY_LOG_FACILITY > > > > > > > > > > > > // Define the listening ports and addresses > > > > > > port=MY_SIP_PORT > > > > > > tls_port_no=MY_SIPS_PORT > > > > > > > > > > > > > > > > > > // Define TCP parameters > > > > > > tcp_children=4 > > > > > > tcp_no_connect=no > > > > > > tcp_rd_buf_size=16384 > > > > > > tcp_max_connections=2048 > > > > > > tcp_connection_lifetime=3605 > > > > > > disable_tcp=no > > > > > > #!ifdef WITH_TLS > > > > > > enable_tls=yes > > > > > > #!endif > > > > > > > > > > > > > > > > > > listen=MY_IP4_ADDR > > > > > > #!ifdef WITH_LOCALHOST_SIP > > > > > > listen=IP4_LOCALHOST > > > > > > #!endif > > > > > > #!ifdef WITH_IPV6 > > > > > > listen=MY_IP6_ADDR > > > > > > #!ifdef WITH_LOCALHOST_SIP > > > > > > listen=IP6_LOCALHOST > > > > > > #!endif > > > > > > #!endif > > > > > > > > > > > > #!ifdef WITH_WEBSOCKETS > > > > > > listen=MY_WS4_ADDR > > > > > > #!ifdef WITH_LOCALHOST_WS > > > > > > listen=LOCALHOST_WS4_ADDR > > > > > > #!endif > > > > > > #!ifdef WITH_IPV6 > > > > > > listen=MY_WS6_ADDR > > > > > > #!ifdef WITH_LOCALHOST_WS > > > > > > listen=LOCALHOST_WS6_ADDR > > > > > > #!endif > > > > > > #!endif > > > > > > #!ifdef WITH_TLS > > > > > > listen=MY_WSS4_ADDR > > > > > > #!ifdef WITH_LOCALHOST_WS > > > > > > listen=LOCALHOST_WSS4_ADDR > > > > > > #!endif > > > > > > #!ifdef WITH_IPV6 > > > > > > listen=MY_WSS6_ADDR > > > > > > #!ifdef WITH_LOCALHOST_WS > > > > > > listen=LOCALHOST_WSS6_ADDR > > > > > > #!endif > > > > > > #!endif > > > > > > #!endif > > > > > > #!endif > > > > > > > > > > > > force_rport=yes // Add received port to VIA > > > > > > > > > > > > loadmodule "pv.so" // Pseudo-Variable support > > > > > > loadmodule "xlog.so" // Formatted logging support > > > > > > loadmodule "sl.so" // Stateless request handling > > > > > > loadmodule "siputils.so" // SIP utility helpers > > > > > > loadmodule "sanity.so" // Sanity check > > > > > > loadmodule "maxfwd.so" // Support for Max-Forward header > > > > > > loadmodule "textops.so" // Text operations on SIP messages > > > > > > loadmodule "textopsx.so" // Extended Text operations on SIP messages > > > > > > loadmodule "sdpops.so" // SDP operations > > > > > > loadmodule "nathelper.so" // NAT traversal helpers > > > > > > loadmodule "rr.so" // Record Route handling > > > > > > loadmodule "outbound.so" // Outbound support > > > > > > loadmodule "path.so" // Path handling > > > > > > > > > > > > #!ifdef WITH_TLS > > > > > > loadmodule "tls.so" // TLS Support > > > > > > #!endif > > > > > > > > > > > > #!ifdef WITH_WEBSOCKETS > > > > > > loadmodule "xhttp.so" // XHTTP support > > > > > > loadmodule "websocket.so" // WebSocket support > > > > > > #!endif > > > > > > loadmodule "rtpengine.so" // RTPEngine control > > > > > > > > > > > > #!ifdef WITH_DEBUG > > > > > > loadmodule "debugger.so" > > > > > > #!endif > > > > > > > > > > > > When I start Kamailio, I see the following in the output to stderr: > > > > > > > > > > > > Listening on > > > > > > udp: 172.16.0.57:5060 > > > > > > tcp: 172.16.0.57:5060 > > > > > > Aliases: > > > > > > tcp: VRTPENGINE:5060 > > > > > > udp: VRTPENGINE:5060 > > > > > > > > > > > > WARNING: no fork mode > > > > > > 0(6299) INFO: <core> [core/tcp_main.c:5042]: init_tcp(): using epoll_lt > > > as the io watch method (auto detected) > > > > > > > > > > > > Here’s the problem: > > > > > > > > > > > > When I connect via UDP, everything works fine. I can connect and see all > > > SIP traffic. > > > > > > > > > > > > However, if I try to connect via TCP, I see the initial SYN packet in > > > attempting to establish a connection. > > > > > > > > > > > > Kamailio responds with an [RST,ACK] message and the TCP connection is > > > never established. No further TCP traffic is sent. > > > > > > > > > > > > Any ideas on what I’m doing wrong? > > > > > > <https://www.google.com/maps/search/3400%0D%0A+North+Ashton+Blvd,+Suite+470+%0D%0A+Lehi,%0D%0A+Utah+84043?entry=gmail&source=g> > > > > > > > > > > > > *Peter H. Manley, Ph.D.* > > > > > > Chief Software Architect > > > > > > KomBea Corporation > > > > > > 3400 North Ashton Blvd, Suite 470 > > > <https://urldefense.proofpoint.com/v2/url?u=https-3A__maps.google.com_-3Fq-3D3400-2BNorth-2BAshton-2BBlvd-2C-2BSuite-2B470-2B-250D-250A-2BLehi-2C-2BUtah-2B84043-26entry-3Dgmail-26source-3Dg&d=DwMF-g&c=aXfg9j-An5sFdflqnjAj_USiCjXm5xEBIX8lTgWEt0U&r=ykVOlDeeWPn-JjTs8avieNrFskQ3kNzjf6_Jn_wG5HLeLIRsvzCN4-dJx6BFR4el&m=MMSIepRfj2CXVMH3CH8SghyPAoonRISMH__5bcNFPLM&s=C4toC0HQ2JwHKiamawbqvdjdidlwyhCP0XVneFagwkY&e=> > > > > > > Lehi, Utah 84043 > > > <https://urldefense.proofpoint.com/v2/url?u=https-3A__maps.google.com_-3Fq-3D3400-2BNorth-2BAshton-2BBlvd-2C-2BSuite-2B470-2B-250D-250A-2BLehi-2C-2BUtah-2B84043-26entry-3Dgmail-26source-3Dg&d=DwMF-g&c=aXfg9j-An5sFdflqnjAj_USiCjXm5xEBIX8lTgWEt0U&r=ykVOlDeeWPn-JjTs8avieNrFskQ3kNzjf6_Jn_wG5HLeLIRsvzCN4-dJx6BFR4el&m=MMSIepRfj2CXVMH3CH8SghyPAoonRISMH__5bcNFPLM&s=C4toC0HQ2JwHKiamawbqvdjdidlwyhCP0XVneFagwkY&e=> > > > > > > www.kombea.com > > > <https://urldefense.proofpoint.com/v2/url?u=http-3A__www.kombea.com_&d=DwMF-g&c=aXfg9j-An5sFdflqnjAj_USiCjXm5xEBIX8lTgWEt0U&r=ykVOlDeeWPn-JjTs8avieNrFskQ3kNzjf6_Jn_wG5HLeLIRsvzCN4-dJx6BFR4el&m=MMSIepRfj2CXVMH3CH8SghyPAoonRISMH__5bcNFPLM&s=ocueS1ZL34IN6qr14M-aItGjeJGQ2km5U2zpzO4Fyqw&e=> > > > > > > > > > > > > Office:+1.801.610.5808 > > > > > > Mobile +1.801.243.7773 > > > > > > > > > __________________________________________________________ > > > Kamailio - Users Mailing List - Non Commercial Discussions > > > * sr-users at lists.kamailio.org > > > Important: keep the mailing list in the recipients, do not reply only to > > > the sender! > > > Edit mailing list options or unsubscribe: > > > * https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users > > > > > -- > > VoIP Embedded, Inc. > > http://www.voipembedded.com > >