Category: Archive
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How to install Mediaproxy 2.5.2 on CentOS 6 64 bit
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Mediaproxy 2.5.2 is a Python application from AG-Projects which is available as a free download as well as being available as a commercial product from AG-Projects. It is used in combination with the Mediaproxy module of OpenSIPS. Mediaproxy 2 has several dependencies and can be quite tricky to install. The INSTALL instructions that come with the package are very helpful, but unfortunately they are aimed primarily at installers who either have Debian or Ubuntu Linux distributions.…
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Setting up shared voicemail on Asterisk – part 2
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Part 1 laid the foundations for creating and accessing a shared voicemail box. In this, part 2, I explain how the lamp on the BLF key is switched on and off to show there are messages waiting in the shared box. Note that this is separate from any existing MWI lamp used for personal voicemail. It uses a custom device state within Asterisk switched by an external application. The external application in this case is a bash…
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Setting up shared voicemail on Asterisk – part 1
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It’s a requirement that people often seem to ask for – a single voicemail box, taking messages for a department, that can be easily monitored and accessed by several different users. A typical application would be to record out-of-hours messages which are then checked in the morning by any of a number of users, perhaps just depending who arrives first at the office. While it is fairly easy to configure Asterisk or Trixbox to record the messages, it is less…
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Using Custom Device States to control BLF lamps
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Do you want to know how to use a custom device state to control the lamp on a programmable key of an IP phone? In this article I explain how to set up the hints and make any number of IP phones subscribe to a custom device state and how to switch the custom status from within the Asterisk dial plan. In later articles I plan to show how this can be put to a practical use. I will explain how to…
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E1
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E1 E1 is an ITU-T standard that defines the basic protocol and structure for transmission of TDM data over a physical circuit (most often the physical connections use twisted pairs and conform to G.703). It is widely used in Europe. An E1 primary rate trunk has a total of 32 time slots allocated within each frame of data. In TDM telephony applications, time slot 16 is used as a data channel (the D channel) and carries call setup, clear down and…
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TDM
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TDM Stands for: Time Division Multiplexed This is one method by which multiple streams of data are combined together into a single stream of data for transmission down a cable or optical fibre. The combined streams may then be separated out again into individual streams at the far end of the cable as required. When digital data are merged using time division multiplexing, the resulting merged data stream is structured as a series of small blocks, called…
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How secure is your Asterisk PBX? – part 3
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Getting more advanced In part 2, we looked at several ways in which an Asterisk system administrator can help to make their system more secure, with special emphasis on avoidance of toll fraud. In this, the third and final article in the series, I will pick up on a topic that was left unfinished at the end of part 2 – sip domains. I also want to look at a couple of other topics that were barely touched…
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How secure is your Asterisk PBX? – part 2
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Protecting your Asterisk server In part 1, we examined the techniques that are used to probe for vulnerabilities in a SIP server and reviewed the types of exploitation a would-be hacker hopes to use. In this second part, I look at the ways you can protect your Asterisk or other SIP server and guard against weaknesses that could potentially cost your organisation a lot of money. This article was written before the pjsip channel driver was available,…
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How secure is your Asterisk PBX? – part 1
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A growing problem Like a slice of Victoria sponge cake on a summers day attracts wasps, so new technologies seem to attract the attention of cyber-criminals. The more widely used the technology, the greater the interest. It was inevitable, and widely predicted, that VoIP would become a favorite target for hackers as its popularity and uptake increased – it has the accessibility of an email server combined with the potential for fraud of an online bank account. Irresistible! And so…
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Installing Mediaproxy 2 on CentOS 5 64bit
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Mediaproxy 2 is a Python application from AG-Projects which is available as a free download as well as being available as a commercial product from AG-Projects. It is used in combination with the Mediaproxy module of OpenSIPS. Unlike Mediaproxy 1, the new version has a lot of dependencies and it can be quite tricky to install. The INSTALL instructions that come with the package are very helpful, but unfortunately they are aimed primarily at installers who…
