I designed this website with the impossible mission to appeal to the novice and the non technical alike. So articles like this propose a challenge that I hope through the blog, I can overcome.
There are multiple phases to a VOIP project. There are many similar characteristics regardless of enterprise or carrier, small or large that need to be defined before anyone starts with the initial design. Here are the different components of a typical VOIP environment. The terms vary but the philosophy is still the same.
- OSS/BSS
- Voice components
- Security components
- Network Infrastructure
- Extra Services
SIP
SIP is an industry standard in a industry which claims many standards. SIP is a lightweight protocol which is very similar to HTTP. It’s message format is almost identical. It is also as easy to troubleshoot. If you know how to use a sniffer, you can debug any problem in minutes. Here is a list of SIP response codes:
- 1xx: Provisional — request received, continuing to process the request;
Provisional responses, also known as informational responses, indicate that the server contacted is performing some further action and does not yet have a definitive response. A server sends a 1xx response if it expects to take more than 200 ms to obtain a final response. Note that 1xx responses are not transmitted reliably. They never cause the client to send an ACK. Provisional (1xx) responses MAY contain message bodies, including session descriptions. - 2xx: Success — the action was successfully received, understood, and accepted;
- 3xx: Redirection — further action needs to be taken in order to complete the request;
- 4xx: Client Error — the request contains bad syntax or cannot be fulfilled at this server;
- 5xx: Server Error — the server failed to fulfill an apparently valid request;
- 6xx: Global Failure — the request cannot be fulfilled at any server.
Let me offer a brief history of the topic and then I will give my view on where technology is headed including how IMS fits in. There are people who just operate, we call them technicians, there are people who design hence architect, and then there are people who engineer. An engineer is not a guy who sits and designs. An engineer is a thinker; a philosopher of sorts who learns how things are designed and either makes them better or knows the little pieces enough to reproduce. Engineers implement, integrate, and improve technology. The world is full of technicians.
In knowing this, if you are sitting next to a computer today and haven’t even thought about how you connect to the Internet, then you are not an engineer. If you are working in IT then you shouldn’t even have the initials “eng” next to your name.
Remember the dial-up days when you had to have that AOL account, and yes I had an AOL account, and they would give you access numbers out of the kazoo to make you think their presence was “everywhere”? Cool trick. Sadly this was not true, but it did mark the beginning of IP convergence.