Opening Compressed PCAPs with SNGREP

The wonders of troubleshooting SIP never cease. Ever try to open a pcap with sngrep only to get the following error? Couldn't open pcap file XYZ.pcap: unknown file format And then, even though you hate looking at SIP on wireshark, you are left wondering… Why does this file open in Wireshark, but not in sngrep? Well, most of the time, this is because the pcap file is actually compressed. Easy fix....

July 14, 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

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

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

Hi. My name is Fred, and I'm a Kamailian.

I got thrown into VoIP in a sink or swim situation — and thankfully, I’m a strong swimmer. I’ve talked previously about my love of phones. Growing up in New York City, my family would purposely avoid walking on certain blocks to avoid me seeing pay-phones. As a child, I loved phones. I still love phones. My love of phones made me what I am today. I am a Kamailian. ...

July 28, 2011 · 3 min · Fred Posner