What is VOIP?

Many people either have no idea what VOIP is, think its unreliable, or can't see the point in it. To be fair for people who have mobile phones with hundreds of free minutes and land-line telephones with free weekend and evening calls it can appear on the surface to be pretty pointless. However there are some advantages which may affect you:

More than one telephone line for free...

If you live in a household with three or more people in it you have undoubtedly encountered the situation where you either wanted to use the phone when it was already in use, or got annoyed by someone else constantly picking up your private calls. With VOIP this problem is solved...

If you want more than one line whether its for business or pleasure get another one - for free. No installation, no setup fees, nothing; just install a bit of software or pop out and get yourself a VOIP phone and you're good to go. Most providers even give you your own free voicemail!

Answer your phone from anywhere...

Another advantages of VOIP is the phone number isn't physically tied to a specific location. If I unplug the VOIP phone from my house and plug it in at a friends house (with Internet access) my phone number goes with it. I could even have phones in multiple physical locations and they would all ring at once! Indeed if I use a WiFi phone or a software phone on my laptop my number goes with me wherever I have an Internet connection.

Free phone calls...

Perhaps the most hyped feature of VOIP (but in my opinion the least convincing argument for it) is free telephone calls. These days with just about every telephone operator giving out free local and national calls but VOIP only giving free calls to other VOIP phones it seems kind of pointless; although if you often call abroad VOIP can be very useful.

Skype - You Can't be Serious?

Over time it has constantly baffled me why the world as a whole has continuously adopted inferior systems. For example: Even though both systems have evolved considerably from their early routes neither Windows or IBM PC's provided a good starting point compared to the other options available at the time. We would probably be years ahead of where we are now if one of the other platforms had been adopted instead.

VOIP is no exception... For some reason the masses appear to be swarming around Skype which is in my personal opinion the MSN Messenger of the VOIP world. I don't have space here to go into the complexities as to why I think Skype is a 'toy' VOIP client but one key point is the fact that Skype is a proprietary closed source protocol. In an Internet based on open protocol communications - where anyone can make an email client, an email server, a web browser, a web server or even a wireless router it seems crazy to support a closed system with a single point of control.

At the moment we have the freedom on the Internet to do almost anything we want for nothing, can you imagine where would we be today if only one company were allowed to control the everything? We would probably be paying 1p per page or have adopted some crazy web browsing subscription fee and have a limited choice of mass media providers websites (much like satellite TV has evolved into).

SIP - A Real VOIP Solution!

Luckily there is a real alternative to Skype called SIP. SIP is an open standards VOIP solution with software and hardware telephones ranging from simple software applications (which you can run on everything from your computer to your mobile phone) all the way through to full blown hardware solutions such as WiFi or cabled VOIP phones made by Grandstream and Linksys.

For the telephone exchange side anyone can run their own SIP gateway simply by downloading some free VOIP software and having a voice modem. Either that or more simply they can chose between a multitude of suppliers - many offering free services. Personally I use Sipgate and have received excellent service from them even when only using their free service.

VOIP Phones

I don't know about you but I'm not a big fan of software based VOIP. I think if you are going to seriously use a telephone you can't beat a solid piece of always-on hardware that sits on your desk with a display and a handset (and in my case a headset as well so I can type and talk at the same time). I've had a few phones in my time ranging from a Grandstream BudgeTone 101 (which whilst it did the job admirably and reliably it was uninspiring and lacked basic functionality like speed dials) through to a WiFi UTStarcom F1000 (which although not as reliable as the BT101, supported a rather nice, well featured, simple to use interface - which for anyone who has used an old Nokia would be almost second nature).

VOIP phones have come a long way since those early models though and more modern hardware is nothing short of your standard house phone on steroids. Just recently I started using a Grandstream GXP2010 for my business and trust me it is simply awesome. Supporting multiple lines (so I can have local telephone numbers for more than one dialing code on the same phone for free) a fantastic display and easy to use clearly marked buttons this phone is truly a breath of fresh air in the VOIP world. Nearly everyone I know thats used it didn't even know it was a VOIP phone!

Being from the cheaper end of the market people often turn their noses up at Grandstream VOIP phones, preferring models by Cisco, Linksys and others. After using the rather basic BT101 I can understand where they may be coming from, but newer phones such as the GXP2010 are a different kettle of fish. In my opinion the amount of features, ease of use and fantastic display on this phone make it something special, especially for its incredibly low price tag.

Setting up SIP

If you are new to SIP, setting up can be a little daunting. Its probably true to say one of the reasons many people use Skype is it requires no skill to set up - but often making that little bit more effort up-front can reap considerable benefits in the long run and SIP is no exception.

If you are new to the game I'd stick with a commercial SIP gateway provider who can give you assistance and even preconfigure your phones for you. The phones I've purchased from Sipgate worked straight out the box and form most of the ones I've had to configure myself Sipgate provided easy to follow step by step instructions on their website. However to give you an idea of how SIP works please read below...

SIP VOIP basically uses two ports:

RTP (Usually UDP 5004): This is the port that carries your audio
SIP (Usually UDP 5060): This is the port that sets up the call

Some really advanced phones use other ports for multimedia etc. but basically these are the main two ports you need to set up audio communications.

Now obviously its not possible to set up port forwarding on firewalls wherever you go, so to make life easier we use a service called STUN. Configuring STUN on your phone means you don't need to worry about special configuration on your router as STUN will act as a proxy between you and the SIP gateway organising all the connectivity for you. This is especially useful on mobile (WiFi) VOIP phones as it means no matter where you go the phone can get a connection without having to mess around with settings. A good quality VOIP phone configured with STUN should 'just work' as long as you have an Internet connection.

Putting the extra effort in to make a solid reliable SIP setup you can trust...

STUN is great for mobile use but for fixed installations I prefer to directly route the calls/ports to my phone rather than go via STUN. The reason for this is using STUN to work around your router can often introduce connection delays and intermittency during call negotiation (basically because its an extra layer of complexity). Setting up direct routing offers considerably more stability (especially if you have more than one line) and also for me it solved many of the annoying VOIP type problems people often complain about such as calls dropping straight into voicemail and repeatedly going offline. I strongly recommend directly routing your ports if you have a VOIP phone which you know is going to stay in the same place.

Direct routing setup is quite easy just follow these simple steps. Anyone who has set up port forwarding on their router for online gaming will find this very familiar:

1. Find out what ports your VOIP/SIP provider uses for SIP and RTP. (Usually 5060 UDP and 5004 UDP).
2. Configure your phone to always use the same IP address on your LAN. You can do this either by setting a static IP address on your phone or by configuring your routers DHCP server to always give out the same address.
3. Connect to your broadband router and forward the SIP and RTP port numbers directly to the IP address your SIP phone is using.
4. On your phone configure the SIP and RTP ports to match those of your provider and router then disable STUN.
5. (Optionally on some routers you may need to disable uPnP as this can sometimes cause problems.)

Once you have done this should see a noticeable improvement in your VOIP phones performance.

(Its worth noting that if you have more than one VOIP line/number/phone you need to configure a different SIP and RTP port for each one. Your provider should be able to give you assistance on this one but for example in the case of Sipgate the SIP port numbers go up incrementally 5060, 5160, 5260, etc and the RTP port numbers similarly as 5004, 5104, 5204, etc.)

Conclusion

I've been using SIP VOIP for about 3 years now and I can honestly say I have found it to be a reliable service without which, I would have ended up paying a lot more for telephone lines. Like anything though, if you set it up badly and you will get bad results; however set it up well and everyone will just think its a normal phone.

Posted by Daniel: 12:09, Sun 16th Mar 2008