APT fails: NO_PUBKEY

Ever get an error like this when running an apt update? The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B4D2D216F1FD7806 or W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://download.jitsi.org stable/ InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B4D2D216F1FD7806 W: Failed to fetch https://download....

April 1, 2022 · 1 min · Fred Posner

Kamailio Install Module Git

Generally, when I deploy Kamailio, I use git. Many reasons for this (including being able to quickly apply a patch or fix), but that’s a discussion for another time. If you’ve installed from git and need to add a new module (that hasn’t already been built/installed), the process is very straight forward (and simple). Step 1: Install Dependencies Some modules require libraries to be installed. For example, the jansson module wants the jansson library to be installed....

December 16, 2021 · 1 min · Fred Posner

Thanksgiving Message 2021

Last Thanksgiving, thanks to Covid, Thanksgiving was quieter than normal. This year, travel is expected to be close to pre-pandemic levels (air travel alone is expected to be 91% of what it was pre-pandemic). This said, we’re staying in Gainesville for the holiday and having a quiet celebration. Some of my family will joining my parents in Fort Lauderdale (which is looking like a decent, although smaller, turn out). We opted to stay in Gainesville primarily for AnneMarie....

November 24, 2021 · 2 min · Fred Posner

Freeswitch 1.10.7 Released

The major announcement at ClueCon 2021 was the release of FreeSWITCH 1.10.7. Highlights from this release: fixes for security advisories (upgrade today) support for Debian 11 bug fixes etc There’s a great presentation from Sandro Gauci regarding the story behind some of the vulnerabilities he (and his team) discovered/submitted. Included in his story, is one of my favorite moments from Kamailio World. Read More Enable Security: Killing bugs … one vulnerability report at a time Speaker Deck: Sandro’s slides from ClueCon FreeSWITCH 1....

October 29, 2021 · 1 min · Fred Posner

APIBAN Now Has IPset

APIBAN helps prevent unwanted SIP traffic by identifying addresses of known bad actors before they attack your system. Bad actors are collected through globally deployed honeypots and curated by LOD/APIBAN. APIBAN started from discussions at tech conferences (in particular Kamailio World and Astricon). Most of the attendees had seen increases in malicious SIP traffic and we all thought there should be a way to share the active “bad actors.” When I found myself with some downtime, and with the support of LOD, some honeypots were deployed… and API made to share the data, and APIBAN was born....

October 21, 2021 · 2 min · Fred Posner

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

Moving to Hugo

After spending many years on Wordpress, I’ve decided to make a change in the software running this site. First of all, I have absolutely nothing against wordpress. I’ve used wordpress for well over 15 years at this point. There’s a simple reason why so much of the web is powered by wordpress – it’s clean, easy to run/maintain, and there’s great templates available. You can literally get started in 5 minutes....

September 29, 2021 · 1 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

Thanksgiving 2020

Normally, I write these posts the night before Thanksgiving… after all, Thanksgiving remains my absolute favorite holiday. A time to gather with family (remember…. friends are the family you choose), express gratitude, and eat great food. The gather part this year didn’t happen thanks to the pandemic. Losing the bakery and not seeing family/friends since February made it hard to focus on what we have to be thankful for… not as hard as when Ricardo was murdered, but honestly it’s been a shit year....

November 27, 2020 · 2 min · Fred Posner

The Palner Group @ 20 Years

Twenty years ago, I started The Palner Group, Inc. with the goal of providing technology consulting as a service. 2000 feels like a century ago (I’ve not thought about the millennium bug for some time now) and I’m using this anniversary to reflect on having this company for two decades. The Palner Group, Inc. isn’t my first business. A few years earlier I had started a nutritional supplement sales company (Vitastorm) with a great friend of mine, Rick Pallisso....

October 1, 2020 · 3 min · Fred Posner