sr-users February 2025

sr-users@lists.kamailio.org

34 participants
26 discussions

Best practices for proxy protocol and TLS offloading
by Alex Balashov 04 Mar '25

04 Mar '25

Hello, I am converting a Kamailio WSS/TLS gateway to pure TCP, with an external HAProxy handling TLS termination and emitting the proxied connection as plain TCP. I am using the PROXYv2 protocol, with `tcp_accept_haproxy=yes`, to convey the upstream network and transport-layer reachability info into Kamailio. I am trying to figure out best practices for mapping the contacts on those connections to the proxied connections themselves. For registrations, tcp_force_alias() (with `tcp_accept_aliases=yes`) works well, and inbound calls go to the right place. However, I'm not quite sure what to do with other flows, such as, for example, in-dialog requests on inbound calls going to the TLS endpoints. There are obviously a lot of possibilities, all or most of which I've tinkered with. These generally involve either {s.replace}-ing `;transport=tls` with `;transport=tcp` in the contacts received from the client, or using the traditional `nathelper` contact alias / RURI alias bag of tricks. However, I don't like the former solution because it leads to a non-compliant R-URI going to the endpoint (it's not the ;transport it sent in its contact), and I don't like the latter because it seems like there are too many moving parts. When tcp_force_alias() works so well for registrations, there must be some small linchpin I'm missing for normal request-reply flows. What is it? Thanks in advance! -- Alex -- Alex Balashov Principal Consultant Evariste Systems LLC Web: https://evaristesys.com Tel: +1-706-510-6800

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Topos Module Questions
by David Tek 04 Mar '25

04 Mar '25

Hello, I am trying to configure the Topos module and have some questions. # topos:msg-outgoing vs topos:msg-sending https://www.kamailio.org/docs/modules/5.8.x/modules/topos.html#topos.e.msg_… I am trying to understand the difference between these two event routes(beyond the content of the SIP message ). I notice that both are invoked when OPTIONS are generated by the local Kamailio server but only msg-sending is invoked for messages transiting the Kamailio( ie proxied, not locally generated). Is there some difference in how these event_routers are invoked beyond the content of the SIP message? # tops -> requests/replies When I am in event_route[topos:msg-sending] { and invoke 'drop', does this apply to the current message or does it apply to the transaction? I have a Kamailio node with devices on either side. Let's call side A untrusted and side B trusted. I want TOPOS happening against the untrusted device but not the trusted device. I have found that when I invoke 'drop' on a request coming from A to B, it disables TOPOS not only on that packet, but also the reply comes from B back to A, TOPOS isn't applied when the reply exits Kamailio towards A. So if I call 'drop' on the request coming from A to B, the reply coming from B to A has no TOPOS applied. How do I get TOPOS applied to all traffic facing a particular device while leaving that traffic un-stripped when the same traffic is interacting with other devices that are trusted? Thanks, David

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Torso Sex Toy for Men & Women
by feifeiwangf＠uusextoy.com 04 Mar '25

04 Mar '25

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KEMI logging function name output
by Dmitry Sytchev 28 Feb '25

28 Feb '25

Hi all! By default logging from KEMI with KSR.log() is prefixed with something like this: <core> [core/kemi.c:152]: sr_kemi_core_log(): Can we somehow disable this not to print it every time with every message? Thanks! [image: image.png] -- Best regards, Dmitry Sytchev

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SNMP thresholds
by Sergio Charrua 27 Feb '25

27 Feb '25

Hi all! we have set SNMP stats on our production server. The server is only receiving 1% of the calls, less than 1 CAPS, but we are receiving some SNMP alarms that are a bit weird to us. [image: image.png] This is an example. As we were unsure about the thresholds to be set for Msg Queue, we set Minor to 20 and Major to 100, which resulted in some alarms when we exceeded the Major threshold. From our understanding, the Max Major MSG Queue threshold was 2176, which obviously generated an alarm. But we can't understand why when a Msg Queue depth of 1280 generated an Minor Threshold alarm when the threshold is 20!! Why not generate a Major Threshold alarm instead, as it did reach the Major Threshold ? Also, does anyone have a clue on how to estimate Major and Minor thresholds? How does this Msg Queue handler work? Is it Kamailio's level or on OS/Kernel level that it gets the statistics from? Apart from the official Kamailio SNMPStats docs, any doc or article one would share? greatly appreciated. ( I so much hate SNMP!!! :) ) Atenciosamente / Kind Regards / Cordialement / Un saludo, *Sérgio Charrua*

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Tweaking TCP/TLS connection timers
by Ihor Olkhovskyi 27 Feb '25

27 Feb '25

Hello, I'm observing a bit strange behavoir of Kamailio, but maybe I'm wrong in my assumptions. In some cases Kamailio just closes absolutely valid TCP connection, as I see it in Wireshark [image: image.png] At the same time I do see in Kamailio logs a lots of lines with tcp_timer_check_connections(): message processing timeout on connection id: XXXXX (state: 0) - closing I see that many TCP connections are closing (and it's ok as we have mobile devices connected and loosing connections for them is ok) But for me this connection is perfectly ok looking on TCP keepalives, what can cause this behavoir? I have these TCP options tcp_connect_timeout=30 tcp_conn_wq_max=63536 tcp_crlf_ping=yes tcp_delayed_ack=yes tcp_fd_cache=yes tcp_keepalive=yes tcp_keepcnt=3 tcp_keepidle=30 tcp_keepintvl=10 tcp_linger2=30 Kamailio 5.8.3 Any hints are appreciated. -- Best regards, Ihor (Igor)

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Kamailio and TLS-PSK Support
by Юрій Пивоваров 27 Feb '25

27 Feb '25

Dear Kamailio Community, I am currently exploring the possibility of configuring Kamailio to use TLS-PSK (Pre-Shared Key) for secure SIP signaling. Has anyone successfully configured Kamailio to work with TLS-PSK? If so, could you share any guidance, configuration examples, or relevant modules that need to be adjusted? In this setup, the SIP client will be a device with very limited resources, making it impossible to use certificates. This is why I am specifically looking into a TLS-PSK solution. I have also tried configuring stunnel as a proxy and set listen = tcp:127.0.0.1:5061 in kamailio config, but I haven't been able to get it working. Any suggestions on what might be missing or misconfigured? Thank you in advance for your help!

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Drop RTP Flow and move to another point
by Social Boh 26 Feb '25

26 Feb '25

Hello List, before spending much time on solving this scenario, I'd like to know if this kind of operation can be done using some Kamailio function (maybe dlg_req_within?) or other method. The scenario is: a B2B-1 server call two different destinations, one is a SIP trunk and another is another B2B-2. Both calls go through Kamailio which uses RTPEngine for the media flow. The idea is to drop the first B2B from RTP Flow (leave for signaling) when both calls are answered and leave everything to Kamailio-RTPEngine, like: LegA: Kamailio-RTPEngine -> B2B-2 LegB: Kamailio-RTPEngine -> SIP trunk Thank you in Advance Regards --- I'm SoCIaL, MayBe

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PRACK Retransmission and 408 Timeout Issue in Kamailio
by 高秉寬 26 Feb '25

26 Feb '25

Dear Kamailio Developers, I am using Kamailio as a SIP server to facilitate a phone call, but I am encountering an issue where the call cannot be established due to Kamailio sending a 408 Request Timeout to the caller. Issue Details: - A (Caller) sends an initial INVITE to Kamailio, which then forwards it to B (Callee). The INVITE contains the following Supported header: Supported: timer,100rel,replaces,precondition,from-change,histinfo,tdialog I suspect the *precondition* option may be relevant to the issue. - *B* responds with a *183 Session Progress* message, which includes: Require: 100rel,precondition Kamailio correctly forwards this response to *A.* - *A* then sends a *PRACK* request to Kamailio. However, this request contains: Require: sec-agree Supported: timer Notably, *precondition* is absent from both the *Require* and *Supported* headers. - Kamailio forwards this *PRACK* to *B*, and *B* responds with *200 OK*, including: Supported: 100rel,from-change,tdialog - However, Kamailio does not seem to acknowledge *B's 200 OK* and instead *keeps retransmitting the PRACK* to *B*. B responds with *200 OK* again, but the cycle repeats. - After three retransmissions of *PRACK*, Kamailio eventually sends *408 Request Timeout* to *A*, leading *A* to send a *CANCEL* request. Device Used: - *Caller (A):* Asus ROG Phone 5 - *Callee (B):* Asus ROG Phone 6 Both are commercially available mobile phones. Possible Cause: According to *3GPP TS 24.229, Subclause 5.1.3.1*, If the received response with an SDP body includes a Require header with > the "precondition" option-tag, the originating UE shall include a Require > header with the "precondition" option-tag in responses with an SDP body to > subsequent requests that include an SDP body and include the "precondition" > option-tag in either the Supported or Require header field received > in-dialog. In this case: - The *183 Session Progress* from *B* contains Require: *precondition*. - The subsequent *PRACK* from *A* does not include *precondition* in either *Require* or *Supported*. Could this mismatch be the reason Kamailio keeps retransmitting *PRACK* and ignoring *B's 200 OK*? Or could there be another factor causing Kamailio to behave this way? If additional details are needed, please let me know. Best regards, Ping Kuan Kao

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Issue with registrations
by Anthony Ford 26 Feb '25

26 Feb '25

Hi Version = 5.6.0-dev0 We are seeking help to resolve an issue with registering devices to 3CX (All 3CX servers, have tried 8 different ones) . all the auth info including passwords etc are identical on the 3cx servers. We use Kamailio to register mobile sim cards to 3rd party sip servers i.e. 3CX. We send the normal Username, server addresses and auth details but are experiencing failures with 3CX rejecting the registration and return Proxy Auth failure 407. We have noticed in the pcaps from both sides that the expire value is changing from 180 as an example to 0. As an example In the uac reg_dump the values are : l_uuid: +447529135850<tel:+447529135850> l_username: +447529135850<tel:+447529135850> l_domain: sbc-mt.asim.apalo.io<http://sbc-mt.asim.apalo.io/>;transport=udp r_username: 1001 r_domain: egte.3cx.uk<http://egte.3cx.uk/> realm: <null string> auth_username: FdlHDC1IvA auth_password: extracted auth_ha1: none auth_proxy: sip:egte.3cx.uk:5060 expires: 60 flags: 0 diff_expires: -1738853736 timer_expires: 0 reg_init: 1738850836 reg_delay: 0 contact_addr: k01.asim.apalo.io<http://k01.asim.apalo.io/>;transport=tcp socket: <null string> [cid:image001.png@01DB86AB.2701F190] [cid:image002.png@01DB86AB.2701F190] [cid:image003.png@01DB86AB.2701F190] Looking forward to hearing from you. Many thanks Tony Ford

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sr-users February 2025