I can't tell you how many calls I field from business owners who have heard of SIP but don't understand it at all.
Let's start with a definition. "SIP" stands for "session initiated protocol" which in basic terms is a method of sending voice over an IP network. You have probably heard of the term "VoIP". Well VoIP typically uses SIP to communicate.
SIP has been around for a few years now and serves two main purposes in the telecom world.
1- Alternate carriers use SIP to deliver discounted business telephone access to IP enabled telephone systems. (In other words they compete with Telus, Bell, Shaw....)
2- SIP is also used to connect remote or "home worker" IP phones back to the main business telephone system. This is used more and more as businesses move to having "home based employees".
In both of the two main purposes SIP can be a very effective and affordable solution but it is not without it's pitfalls!
As previously mentioned SIP is a network service and as such it resides on your Local Area Network and more often than not shares your Internet connection. It is always recommended that your SIP traffic has it's own Internet connection however there is a cost to this so this recommendation is not always followed.
Don't be discouraged however because you can share your Internet connection- you just have to ensure that you have adequate bandwith for your SIP (voice) traffic.
SIP is definitely here to stay and we are seeing more and more services being provided via SIP. I predict that it will not be more than 5 years before all of your communications services are delivered via your High speed Internet connection! That includes your Telephone, your Cable TV and whatever else a business needs by then!