Inside the Asterisk

Keyword: debugging

Debug Logging by Category

Logging in software is usually a good thing. It’s often used to output useful information and/or statistics relevant to a current software task. However, everything comes with a cost, and logging is no exception. Excessive logging slows a system down. As well “information overload” can actually confuse a situation and complicate things. Like any good

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Asterisk ACN: Advanced Codec Negotiation

Codec negotiation in Asterisk has been one of its deepest darkest secrets.  It’s been around since the beginning and over the past two decades it’s grown and mutated into one of the least understood parts of Asterisk.  With Advanced Codec Negotiation that’s about to change!  One of the Asterisk team’s goals for 2020 was to dig

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Improving Core Dump Analysis

Within the Asterisk project we are constantly trying to improve our processes and data collection when a problem is encountered to reduce the back and forth for getting information. This initially started with the ast_coredumper script that is now the recommended way to collect information from a running Asterisk process or from a core dump

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Issue Walkthrough: DTLS, and the Case of Bad Audio

A past post discusses some tips and tricks to employ when encountering a problem. Here we’ll walk through an issue applying some of those techniques. Recently an Asterisk issue came up involving occasional static and/or silence for audio. Broadly speaking the problem can be described as Alice calls Bob (using SIP), Bob answers, the call

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Debugging Tips and Tricks

Overview One of the most challenging things about coding is when your code doesn’t work and you have to figure out why. Trying to track down a problem can be half the battle. You might not know what’s causing the problem, how to fix it, or where to look in the first place. This can

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stasis: Statistics CLI Commands

Previously on this blog I talked about a new feature to internally filter messages in our internal message bus, as well as a new caching implementation for it. When these were being developed logging had to be manually added to understand the impact. As of the next version of Asterisk a new feature will be

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The Case Of The Misunderstood PJSIP Callback

When the PJSIP work for Asterisk began one of the primary concerns kept in mind was that it be extensible. One of the APIs derived from this concern was session supplements. Session supplements are a way for modules to add themselves in to the handling of SIP messages for sessions (or calls as you may know

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Debugging SIP message traffic with PJSIP History

Debugging SIP Messages the Traditional Way Since its release, the PJSIP stack has provided logging of SIP message traffic via the pjsip set logger  CLI command. This dumps all received and transmitted SIP messages as a VERBOSE message. This is useful for two scenarios: When wanting to log all SIP messages in an Asterisk log

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