Handling Non-SIP Attacks With Kamailio

Recently, I posted about using Kamailio’s PIKE module to help block excessive SIP traffic. This is a great tool for helping your system handle high traffic SIP, such as floods. But, what can you do when someone sends garbage or non-SIP traffic to your system? Kamailio’s SIP parser is handled in the core and was recently upgraded in v5.5 with logging improvements, as well as simplified implementation, static map for header name, and type for parsing....

October 1, 2021 · 3 min · Fred Posner

Handling SIP Flood Attacks Using Kamailio

The Pike module in Kamailio provides detection and alerting of “excessive” SIP traffic to your system. Within the module you can configure the rate limit, time period, and amount of time that the IP (ipv4 or ipv6) should be blocked. For example, you can configure your system to say that 30 requests from the same IP within 5 seconds should trigger a block of that IP for 5 minutes. I absolutely love this module and, in my case, Pike more often finds abusive traffic (like dialers) than SIP floods attacks....

September 26, 2021 · 3 min · Fred Posner

Simple TLS Gateway

Well, 2020 is certainly a strange year… Some of us have been working from home for a very long time while others are now just understanding the benefits. Of course, when a drastic change in work environment becomes a forced change, the implementation can be quite daunting. Let’s look at telephony for example. Many small, medium, and even enterprise PBX deployments have been designed to only allow endpoints (aka phones) to connect from within the local network....

May 5, 2020 · 2 min · Fred Posner

Kamailio, RTPengine, Centos8

Had to install kamailio and rtpengine on centos8 recently… hopefully this saves you some time: https://github.com/fredposner/scripts/blob/master/kamailio/centos8_install.md

May 1, 2020 · 1 min · Fred Posner


Had a great time visiting with members of the open source VoIP community in Fort Lauderdale for open source world / itexpo 2020. I was excited to discuss Kamailio and other aspects of communication as well as get some important hardware discussions in person… it’s an interesting time as hardware and software vendors seem to be merging left and right. ...

February 21, 2020 · 1 min · Fred Posner

Coming Soon: ITEXPO

From February 11th through 15th, 2020, Open Source World (or open source summit?) will be colocated at ITEXPO 2020 in beautiful Fort Lauderdale, Florida. This year, I will be speaking the gospel of Kamailio with a presentation entitled, “Using Kamailio to Secure Your Communications” (currently scheduled for February 13th at 3pm). What previously had been Asterisk World has been replaced with Open Source World… and has attracted an incredible array of speakers from the open source RTC community; including Dan Jenkins, Lorenzo Mangani, Anthony Minessale, Nir Simionovich, Jared Smith, James Body, David Duffett, Allison Smith, Eric Klein, and more!...

January 30, 2020 · 1 min · Fred Posner

Go vs Node

I’m not a programmer. Never tried to pass myself off as one — which made for a really, really awkward interview once… but that’s another story. Anyway, I’ve been creating “APIs” in Perl for a while using Perl CGI on NGINX. It’s not a REST API whatsoever, but I enjoy scripting in Perl and (1) got the job done, (2) was fast, and (3) no learning curve. ...

November 18, 2019 · 2 min · Fred Posner

Astricon 2019 Thoughts

TL;DR A few weeks ago, I had some strong concerns over Sangoma’s stewardship of Asterisk and FreePBX. Since that post, Astricon showed that Sangoma definitely appreciates the open source VoIP community and I’m optimistic for the future. I, along with 300+ others, attended Astricon 2019 during the last week of October in Atlanta, Georgia. This year’s Astricon differed dramatically from others — there was no expo hall, fewer presentations, fewer tracks. ...

November 1, 2019 · 4 min · Fred Posner

Fred and Dan on ClueCon Weekly

A special spooky episode of ClueCon Weekly with guests Fred Posner and Dan Jenkins! When Open Source is under attack gasp.Fred Posner and Dan Jenkins on ClueCon Weekly

November 1, 2019 · 1 min · Fred Posner

Kamailio on FLOSS Weekly

Did you catch Fred Posner on FLOSS Weekly discussing Kamailio?Fred discusses Kamailio on FLOSS Weekly FLOSS all about Free Libre Open Source Software. Hosted by Randal Schwartz and his rotating panel of co-hosts every Wednesday as they talk with the most interesting and important people in the Open Source and Free Software community. Fred was honored to discuss Kamailio with this group and would join them again in a heartbeat.

November 1, 2019 · 1 min · Fred Posner