Clustering OpenSIPS for High Availability – Part 3

In this, part 3, we examine how a virtual IP address can be switched between two Linux servers to provide an active/standby failover and how this impacts on OpenSIPS. Part 2 investigated the implications for far-end NAT traversal of clustering two OpenSIPS servers and concluded that the best solution is the use of a virtual IP address. … Read more…

Clustering OpenSIPS for High Availability – Part 2

In this, part 2, we investigate the implications of using more than one IP address on an OpenSIPS server and how this impacts on far-end NAT traversal. We will also see how the use of a virtual IP address can overcome these problems when clustering two OpenSIPS servers. Part 1 reviewed why we might want … Read more…

Clustering OpenSIPS for High Availability – Part 1

Why cluster OpenSIPS? Unlike Asterisk, a typical OpenSIPS server is able to handle a very large number of simultaneous SIP calls. It is generally very reliable and will keep running for many months, or even years, with little or no attention. As a consequence, it is the preferred choice for many VoIP service providers who … Read more…

E1

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. … Read more…

TDM

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 … Read more…

How secure is your Asterisk PBX? – part 3

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 … Read more…

How secure is your Asterisk PBX? – part 2

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 … Read more…

How secure is your Asterisk PBX? – part 1

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 … Read more…

Installing Mediaproxy 2 on CentOS 5 64bit

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 … Read more…

IP Phone Configuration: User Account Settings

Manufacturers different naming conventions While SIP is an industry standard protocol, the names assigned to the configuration fields on an IP phone are far from standardised. The tables below show the text labels that you can expect to see on the web interface configuration forms next to the boxes where you must enter your settings. … Read more…