One of the advantages to using digital communications like VoIP is that the endpoints generally have to register so they can be located on the network. Dialing a phone number isn’t helpful if the phone infrastructure doesn’t know where on the data network the phone belonging to that number is located. Registration not only serves the purpose of making sure only the right people get access to your infrastructure, but also ensures that the phone network knows how to get to the user as well as knowing when the user is available to be reached. Knowing when the user is online and what their current status is, including on a call or maybe doing something where they don’t want to be disturbed. All of this information is provided with a feature called presence—knowing what the status of any user is.

You may not only want to place calls to someone, whether that call is voice or video. You may also want to send an instant message to them. As noted previously, SIP is capable of handling a number of types of sessions. Unified communications (UC) is a way of tying everything together into one package. With a UC solution, you get a number of ways to interact with your coworkers or even with your customers or vendors in a deeper, more meaningful way. This sounds like a sales pitch. The fact is that UC solutions can combine voice, video, presence, and instant messaging together in a single platform and application. On top of that, you may be able to add online whiteboard interaction or possibly even desktop sharing to the mix.

A couple of years ago, I worked with a mid-sized regional bank that was in the process of rolling out a UC solution to interact with their customers. Rather than making a call to a call center, the customer could place a call through a piece of software and get connected to someone who was online. This is where the presence part of the UC solution is so important. Before trying to connect with someone, you can be sure they are around and available to talk. If they aren’t, you might choose to simply send them an instant message and they could get back in touch with you either by phone or by instant message. Again, all through the same application.

Along with UC comes unified messaging, which is an attempt to pull different types of messaging into the same platform. Your voice mail messages would be in with your e-mail messages. You may find this in different voice mail systems. HulloMail, available on mobile platforms like Android or the iPhone, provides not only voice mail but also a setting that allows you to have the audio sent to your e-mail so you don’t have to call into your voice mail in order to listen to your messages. You can just listen to the WAV or MP3 file that gets sent to you. Google also has a unified messaging platform that they got when they acquired the company GrandCentral. Since its launch, it’s been rebranded as Google Voice. You get a phone number from Google, and you can provide additional numbers where you can be reached. Google will attempt to forward calls onto you at your other numbers. If it can’t reach you, it falls back to voice mail. The message will show up in your e-mail in the Gmail account that’s associated with your Google Voice account. On top of that, Google will transcribe the message into text so you don’t even need to listen to the message. You can just read it.

UC solutions often try to provide additional features that wouldn’t normally be part of a traditional phone experience. Google, for example, uses a follow-me feature as mentioned above. You call the one phone number that belongs to your Google account, and Google will fork the call off to as many endpoints as you have provided, hoping to find you at one of them. Other vendors provide similar functionality. You may also have the ability to react differently to individual callers in your contact list. HulloMail, for example, allows me to record different messages for people in my contact list. This way, I can have a more personalized experience for people who may regularly call me and get my voice mail. SIP has provided a lot of capability to offer these enhanced features and programmatic access to our communications experience.