SIP Server Roles.

Now, we had an introduction of few important protocol used in VoIP infrastructure (using SIP). So, now lets see some of the important SIP server Roles in the SIP based form of VoIP infrastructure.

• SIP Registrar server
• SIP Proxy servers
• SIP Location servers
• SIP Redirect Servers
• SIP Conferencing Servers

We will see each of the server roles and their purpose in detail (listed above in a different post), but now lets quickly see what is a Conferencing Server and its purpose in really short form.

When a Meeting is organized the Participants does not know where their participants are and how they are connecting. The problem happens if the users are connected via different networks/at different parts of the world via different end user devices like computer, Laptop, Mobile Phone which could be Smartphone with the Softphone application installed on it or someone dialed in to the Conference (using PSTN).

Hence, in order for all these devices to support different Codecs and different Network bandwidth requirements we need a Conference servers which has the powerful codec filters and mixers. With the help of these Codec Filters and mixers, the media traffic can be disturbed to all the participants who are connected from different parts of the world using different end points.

Lets us try to understand the Conference Server purpose with a example.

Let us consider that you have organized a Meeting with 5 users connected from different part of the world. Please note, this is very interesting because imagine that, once you have 5 participants in a meeting - the speaker connected to a high speed network don't need to bother about the bandwidth requirement of person joining through phone from the Hotel room or a person joining from Laptop from Europe, or a person joining the conference in US with good bandwidth or about another person in US who is currently travelling and attending the conference on his smartphone.

The Conferencing Server will take care of the each participants devices through which they have joined and also calculated the bandwidth present at each end user's end. If the Conferencing server is not doing these tasks, then it would be Speaker's Client responsibility to perform all the calculation and determining the best codec to the used for each end point which is awful lot of task to be carried out form a user's laptop