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VoIP QoS Settings – part 2

July 29, 2011

In part 1, we examined the Layer 2 QoS settings available on most VoIP equipment. In this second part, I will explore the Layer 3 parameters and offer practical suggestions for the values that should be assigned to them. We will briefly look at the history and structure of the ToS and DSCP fields and [...]

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VoIP QoS Settings – part 1

June 17, 2011

The QoS settings on VoIP phones and related equipment can be perplexing. Here, I will attempt to explain what parameters like CoS, ToS, DiffServ and DSCP really mean and offer practical suggestions for the values that should be assigned to them. What is QoS? QoS (Quality of Service) is a somewhat all-encompassing term and means [...]

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IP Phone Configuration: User Account Settings

August 25, 2010

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. [...]

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SIP Outbound Proxy Server Explained

August 23, 2010

Why do IP Phones require a setting for ‘Outbound Proxy Server’? Outbound Proxy Server When you look at the configuration options on most IP phones, you will see a field called “Outbound Proxy” or “Outbound Proxy Server”. In this field you can enter an IP address, a host.domain name or just a domain name (as [...]

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IP Phone Configuration: SIP Proxy Server

August 23, 2010

What is the ‘SIP Proxy Server’ setting on an IP phone? It might be called something different on your IP phone In their wisdom, each manufacturer has made different decisions about the naming of data parameters on their IP phones. So if you look at a Snom phone it uses different names to those on [...]

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SIP Registration Explained

August 23, 2010

How does SIP Registration work and why is it needed? Registration – what it is and why it is necessary IP Phones (and SIP clients in general) need to register with a central server mainly because this allows the phone’s location to be known when it is required to receive an incoming call. The “location” [...]

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Configuring IP phones as Asterisk PBX extensions

February 22, 2009

A first look at the SIP.CONF file It is assumed here that your IP phones all use the SIP protocol to register, make and receive calls. Before an IP phone can connect to Asterisk and operate as an extension, it is necessary to configure user account details on the Asterisk server. The configuration file of [...]

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