Introduction to Voice Over IP

hello again as you know I'm Eli the computer guy over here for everyman IT and today's class is introduction to VoIP or introduction to voice over IP so voice over IP is one of the latest and greatest and most wonderful technologies really it's been around or has been pushed out for commercial use in about the last 10 years this class today is going to be a foundation for understanding voice within a business or enterprise class environment so if all you want to do is set up some little Skype phone and talk to somebody you know your neighbor a state away or your your girlfriend/boyfriend husband or wife this class is going to tell you much more than you need to do this class is going to be about the the fundamental concepts so if you want to connect a business to voice over IP we're going to be talking about voice servers void clients things called hard phones and soft phones we're going to talk about gateways we're going to talk about the protocols we're going to talk about codecs we're going to talk about latency and a quality of service and basically the foundation concept so if you're looking at a migrating an entire business whether there are five people or a thousand people to a voice over IP system we're going to tack about the basic concepts of what you need to know again if all you want to do is go out and buy some little Skype phone or download skype this is probably way too much for you that this is for voice over IP in the business or enterprise class world so so give me a second let me get a few things together and then we're going to go into a class introduction to voice over IP so the first thing that we need to talk about our voice or voice over IP servers or you may also hear them termed IP PBX s so voice over IP servers are the main servers that route your calls through voice over IP phones or devices so you know we talked about in the introduction telephone class and all that where a normal phone system has a PBX so within your building you have a PBX right and from this all your telephones your call boxes your auto attendants everything goes through this PBX so all your phones everything go back to this well the nice part is we are now dealing with a networking world so so this is for a telephone system now remember when we're talking about voice over IP we are not talking about telephones we are talking about data devices that transmit real-time audio communication as we go further in this track this is going to become more and more important like I say right now you may think I'm splitting hairs between a telephone system and a data system that transmits real-time audio communication but when you get into legal aspects of the difference between a telephone and a data system these are huge Congress of local legislators etc have mandated a whole hell of a lot of laws about how a telephone system has to work they haven't mandated any or very many laws on how an instant messaging system that also happens at route and transmit real-time audio communications should work so it's very important like I say when I when I keep talking about the difference between a telephone system and a data system with real-time audio communication this this really does matter and this really really does matter in in the real world like when you're dealing with businesses and enterprises you if you're just dealing like I say with your little home phone and maybe one Skype handset and your house probably doesn't matter but in the business world it really does matter so the first thing to understand with these voice over IP servers over there sometimes called IP PBX is is of course they they use the tcp/ip Ethernet network so basically all of your phones the PBX etc is going to use Ethernet and it's going to use tcp/ip to communicate so now instead of having a telephone PBX with with phones and everything that they're in their own world you now have a phone system that resides on the same network as everything else so you use routers you use switches you use tcp/ip you use computers etc so this is very important we're going to talk about the client systems in a moment you know when we talk in the telephone we talk in the telephone world the introduction to telephone class we talked about stations we're now talking about the voice over IP world and so we're going to be talking about clients again another very important thing once you really understand what's going on so the huge thing with this voice over IP server and the other reason I keep calling it a voice over IP server is if you've taken the server classes you will know that a server is any computer that provides services to other computers on the network so this is a voice over IP server like I say some people call them IP PBX is I would argue that is not technically correct this is a server for real-time communications so voice over IP service so with this this server will connect into your switch like normal and then this will connect into your router like normal the router will then connect off into the internet now all your telephones or clients on the system will then connect to the switch and that is how they will connect to this voice over IP server now there's a couple of interesting things to think about with this voice over IP server is the first is you can have you know your client computers or your client telephones connect to the voice over IP server through the normal network so you have a router you have a switch etc you can also have a analog or digital ports connected to the voice over IP server so some of these voice over IP servers you'll actually be able to plug a normal telephone straight into it so let's you bring in the to your telephone from home some of these voice over IP servers you could plug that home telephone straight into the voice over IP server it depends on whether or not they have the little plugs to allow you to do that so if you need to plug in digital phones or analog phones whatever voice over IP server you buy make sure it has that functionality so with voice over IP servers mainly all the communications happen over your normal Ethernet network tcp/ip you know IP protocols etc but if they have these little ports on here they can also connect normal phones but they've got to have those little ports the next thing is as we talked about before in the other classes is trunk lines so how do you call in and how do you call out from a voice over IP sir now the first way you can do it is if you're doing completely voice over IP you can have something called a voice over IP trunk from a provider so you you have a provider this is not Verizon it's kind of like it's like a company called on sip they're companies out there that will provide you IP trunk lines so you don't need normal telephone lines anymore you can actually get all of your calls straight through the internet so so these companies would provide you Boise over IP trunks so the way calls can come in and out are either through the internet you have one of these providers it provides you a voice over IP trunk and so what happens is when you go to call out your little phone connects to the voice over IP server the voice over IP server then connects to those voice over IP trunks or on your voice over IP server you can have connections then connect you to normal phone lines up from the outside world so I say here in Baltimore we use Verizon for our phone company but whatever phone company you use they have they have their little phone line and again if your voice over IP server has the right plugs you can plug one of these phone lines from your telephone company into the voice over IP server and then when somebody makes a call the call goes through your network to the voice over IP server and then goes out that normal trunk line so this is a normal telephone line and that that goes out to the outside world so so this is the first way a voice over IP server can work so so in this model your voice over IP server basically replaces the PBX that you would have before so before you had a special electronics device called a PBX that routed all your telephone communications now you have a voice over IP server all your voice over IP devices connect to it and then it is the one to route calls out to the outside world now here's something that's really really cool and one of the most wonderful things in the world about the voice over IP system is now that we're doing Oh everything over IP now that we're doing over to everything over an Ethernet network this voice over IP server no longer has to be in our building so you can actually have your voice over IP server hosted on the outside world so over here out in the Internet just like you what you would have an email server out on the Internet you can have the voice over IP server out here and basically you rent this from a company let's say a company like on the sip or other ones they will host your voice over IP server for you so you have all of your telephones in the building all your computers telephones etc they connect to the switch the switch connects to the router and then they all connect to this voice over IP server that's no longer even in your building why because everything now uses tcp/ip and the ethernet networking standard this is a great and wonderful thing because PBX is whether they're normal PBX is normal telephone PBX is or whether they're voice over IP service cost a lot of money ah you know for a basic voice over IP server that you're going to put into a business it's going to cost 2,000 just for the server and then you know you at you add and your phone lines that you have to pay for and add in all this other stuff and it gets to be very expensive well now that you can pay for a simple voice over IP service you just pay twenty five or fifty or whatever it is per month per phone and you no longer have to worry about that box sitting inside of your building so this is one of the very very very great wonderful things about these voice over IP service you get the whole enterprise class functionality all the phone lines everything it all works but it's all now out in the Internet just like email is just like hotmail just like all of those things you no longer actually have to buy the box for that voice over IP server so so this is a brief introduction to the voice over IP servers like I said we'll have more classes so we flesh all of this out these voice over IP servers they can be manufactured by normal companies or companies that you've probably heard of like Avaya or Lucent or AT&T or Nortel Mitel etc and those are proprietary of voice over IP servers or IP PBX s or they now have new companies out such as asterisk or I think it's called SIP X these are free open-source voice over IP servers that basically as long as you know how to install them and set up a computer you can have a completely free enterprise class voice over IP server for the cost of a computer that was in the corner collecting dust so that's that that's pretty cool so these voice over IP servers I mean they act they act like the PBX is that we've talked about they route all the communications they contain the auto attendants they contain the call trees they call it they contain the call paths the hunt groups etc so they do all the routing that the the normal old PBX is did the difference is is they communicate using Ethernet and tcp/ip versus the old phone lines that the old PBX is then again the reason that this is very important is you can have the voice over IP PBX or server inside your building or you can simply pay for the service for somebody else to deal with it so all these telephones and it and such will communicate out to that server in the outside world this is a very very huge important thing and again like I says if you want to experiment like when we get to the end of this and you want to experiment with voice over IP a little bit not only can you buy servers again from Avaya and such but you can buy free completely well I guess you're not buying it you can get completely free open-source voice over IP solutions again there's asterisk there's Switchvox and there's something called SIP X I'll put links to it at the bottom of this at the end but but this is a voice over IP server okay so we talked about the voice over IP server so we have our VoIP server over here and remember this is a server this is a computer that provides services to other computers on the network remember that's what a server is so although people call it like an IP PBX and all that garbage it's really a server it's really a voice over IP server so all of your devices or clients because remember since it's a server clients connect to servers are going to connect to this voice over IP server so whether it's a telephone whether it's a computer that allows you to make calls whether it's your little iPhone whatever it is if it is a device and it's going to deal with with your voice over IP communications it's going to go back and it's going to talk to the server now when we're talking about devices and we're talking about clients you're going to hear two terms set a lot and that is going to be hard phones and soft phones so so what is the difference between those two things a hard phone is is a telephone it looks like a telephone it looks like a telephone that you would think is a telephone you know it's gray or it's white or it's black it's got a little handset on it and it is an actual device that basically all it does is provide telephone service or real-time audio communication service so if you look at a voice over IP telephone it looks like a telephone a soft foam is a piece of software that you install onto a computer to allow that computer to provide real-time audio communications voice over IP so a soft phone is a piece of software that it gets installed onto a computer or gets installed onto your little iPhone you know any of these computing devices if it's not normally considered a phone and you install a piece of software onto it then it is a soft phone so soft phones are software that allow computer devices to act as phones hard phones our voice over IP phones that actually look like phones so if you walked up to it if it looks like a phone and talks like a phone it's a hard phone basically you know if it's a it's a if it's something that you would associate as a phone then it is a phone now the next big thing to understand with the the voice over IP clients is these are all computing devices so whether it's your iPhone whether it's your computer or whether it's this hard phone that we've been talking about these are all computer devices the dumbest the dumbest dumbest dumbest voice-over-ip hard phone is lightyears ahead then then any phone that ever connected into any of the the original PB exes so if you have a normal telephone if you have a normal telephone that plugs into a normal PBX in a normal telephone system that device is dumb there's not a whole hell of a lot - if you understood how to solder and how to put parts together you could probably build one in your home right a hard phone is actually a computer device that looks like a phone so this hard phone is actually a computer and when you go in to configure hard phones so these are phones that look like phones you will actually do thrust do so through a web interface so I used to love the Polycom hard phones you would go to the IP address for that phone when you open it up there is a little web browser because that little thing is actually a web server and you would configure everything through the web server that resides on that hard phone so like I say these things actually do have brain power these even the hard phones are computers that simply look like phones now the final thing to talk about with these voice over IP clients or devices because like I say you know it can be an iPhone it can be a computer it can be a hard phone it can be any number of things is that these devices connect to accounts within the voice over IP server so in the voice over IP server you set up the user accounts like you would in most other servers so if you've dealt with Windows servers or Linux service it's it's kind of the same way so in this voice over IP server if you're setting up let's say extension 105 you would say extension 105 the username is X and the password is X and then you would set a whole bunch of other configuration so you know if you're if you're configuring an account in the voice over IP server there's there's probably 10 or 20 different configurations that you can do but the big ones to understand is that you plug in the extension you plug in a username and you plug in a password why I say these are the most important things is because for a voice over IP client you then go to the client whether it's the iPod or iPad whether it's the computer or whether it's this hard phone and inside even the hard phone you say this phone is extension 105 with a user name of X and a password of X this is very important in the old PBX is everything was configured inside the PBX itself with a voice over IP server you know now have a client-server connection so you create the user account within the voice over IP server and then for the device that will be connecting for the client that is connecting you have to give it the information it needs to provide the voice over IP server so what will happen is you plug in this this information extension 105 username X password X when this phone gets on the network it will connect the voice to the voiceover IP server and it will say hey my username is X and my password is x i1 extension 105 and the voice over IP server will say ok your username and password are correct here you are now extension 105 so if somebody calls in from the outside world they dial extension 105 they will now go to this phone like I say it's all pretty simple the same thing with it with the the little iPhone you know if extension 106 you will plug in 106 to the iPhone username X password X and so if somebody called in for 106 it will go here the very important thing and this is where you have to be careful about with voice over IP it's not complicated it's none of that but understand if you make a mistake and you put user name Y password X or you do a user name X password W if that is not the correct user name and password combination this voice over IP server is not going to allow you to get the extension so that is something that's very important understand so with these voice over IP clients like I say these are now clients these are computer devices that connect to a voice over IP server hard phones are computers that are built to look like phones they're still computers but they are built to look like phones soft phones are pieces of software you install into normal looking computers to make them act like a phone so like I says if you have a normal computer you have a normal laptop computer you have a netbook computer you have an iPod or iPhone you would install a soft phone onto it and that allows that computer to now connect to the voice over IP server and it allows that computer to now act like a telephone one of the biggest things and the biggest things that I've seen that causes people problems in the real world is understand within this voice over IP server you're now going to create user accounts you just like you would create like I say for a Windows Server for a Linux server etc you're going to tell it the extension you're going to tell it a user name and you're going to tell it a password plus about 20 or 30 other things the biggest point is this device out here you will have to go in and you will have to configure within that device and say I won extension 105 the user name is this and the password is this if any of this is incorrect the whole kit and caboodle is not going to work so this is voice over IP clients in a nutshell like I say it's it's not too complicated as long as you can follow all these little lines so we've talked about the servers so the voice-over-ip servers these are these are servers that provide services to other computers on the network those other computers are voice over IP clients those clients can be either hard phones or soft phones they're all computers like I say even that thing that looks like a phone and a phone is actually a computer that looks like a phone you know they all communicate there's user names passwords etc now the next biggest component really the only only other major component in a voice over IP network are the gateways the gateways are what connect different types of communication networks so so way back in the day the gateways really all they did was they turn voice over IP communications into normal telephone calls so what would happen in the old days is you would have your voice over IP server right and let's say you're on the internal network and if you made a call from this phone here to this phone right hit here it was all IP it was it was all voice over IP so I would call into the voice over IP server and then that would route the call to the other voice over IP phone now here's the question what if Bob is out here in the house so so he has a normal telephone right with with normal telephone lines etc he doesn't have a voice over IP Phone so what they did is they created these things called gateways so a gateway what would happen is if you were calling to an outside line what these gateways did is they had normal rj11 telephone connectors on them so you could connect a normal telephone line from the outside world into one of these gateways so the telephone line that you have in your house you could connect into one of these gateways so that gateway would then connect to a normal telephone line and then you could call into Bob's house so basically what would happen is if you call from your voice over IP Phone that would get routed through the voice over IP server that call would then get read to a gateway and then that gateway would send the phone call out on the normal telephone lines so the normal like I say the normal telephone poles telephone lines etc these gateways connected between the voice over IP world and the normal telephone world why this was important way back in the day when I was first learning about voice over IP 10 all years ago is because when you work for enterprise companies see Enterprise companies have lots and lots and lots of offices so you may have your one office here in Middle America like the first company I work for but then you have a thousand or actually let's say they had 60 different offices all over the country right so they already had to pay for internet connections t1 connections to all of the remote offices regardless if they open up a remote office they already had to have an internet connection to each one of these remote offices now here was the thing if you have your billing department so what we did we build customers for we build lots of residential customers for write so if that residential customer is sitting right down here your billing department so our installation department was here our installation department was 20 miles away from where that customer lived but our billing department was all the way back here in middle America so if our billing department wanted to call this customer it would be a long distance charge and again you know when you're dealing with one or two people this isn't a big deal but when the customer service the billing department is a hundred people that's a whole bunch of money so every time they had to call a customer whether it is here whether it's here whether it's here whether it's here whether it's here from Middle America it is always a long-distance call so they were always getting charged for so the initial idea so you understand how voice over IP works and this is still how Skype and all these companies work is what they said is here in our office we are going to have voice over IP phones so we are going to have phones that use our our network connections our internet connect and then here at this remote office we're going to put in a gateway that allows us to call local numbers so there's a voice over IP server here and a low voice over IP server here this server connects to a gateway right so now when our billing department decides to call this person that's here what will happen with the voice over IP traffic is it will get sent over this t1 line down to the voice over IP server that's sitting in our in our building here it will get routed to this gateway and from this gateway it is a local telephone call to that client so basically every office had to have telephone lines anyway in order for them to do business they had to have telephone lines they already had to pay for these t1 connections that cost them five or six hundred dollars a month so all they did is they installed a voice over IP system and then whenever they had to call one of these people instead of having to make a long-distance call so instead of having to make a long-distance call from Middle America all the way to Seattle the call would get routed through the t1 connection they already had to their Seattle office from the Seattle office it would get the call would get sent out a gateway that had a local telephone number on it and then call that client and that saved people a lot of money so what these gateways they're the original main thing that they did was they connected the voice over IP network to a normal telephone network like say I want normal telephone network you know telephone poles etc so that was the main thing with these gateways especially with large companies and when you're thinking about companies like Sears or JC Penney's or Exxon or you know any they have they had thousands of facilities all over the country or all over the world they could route their telephone calls through the internet connection they already had and then pop out and make a local phone call made pretty simple now gateways are used for a little bit more but it's still basically simple as far as you're concerned so now now that there there are services such as Skype such as other like voice over IP services there are now gateways specially designed so that Skype voice over IP traffic can now be turned into normal or sip voice over IP traffic around talk about this in a second so gateways are still used they're either used like I say to connect to the normal telephone lines or for things like if your company or the company are using is already using Skype phone numbers you can have a Skype gateway that now will connect you to a sip of voice over IP system so these these gateways connect different types of communication networks basically so whether it's Skype the SIP whether it's sip the telephone whether it's telephone to skype etc gateways are what connects these different types of communication infrastructure so we've thought about the servers we're talking about the clients now we've talked about the gateways so those are the major components of the network that's what you're basically going to go out and buy you'll buy a voice over IP server or you'll lease one from somewhere you'll buy voice over IP clients you'll buy gateways etc now we need to talk about how those those devices communicate so when you when you make a phone call you know from from one person to another person how is that communication done well voice over IP communication uses protocols so you probably know if tcp/ip or Apple uses Bonjour or net Bui etc well voice over IP uses protocols in order for the communication happens so this is basically just a network language now the standard protocol that I would say you should try to buy systems that use is something called sip sip stands for session initiated protocol so this is the the ratified protocol that lots and lots and lots of companies use so you can buy Cisco sip phones you can buy Polycom sip phones you can buy asterisk sip phones so sip is a protocol that lots and lots and lots of vendors have implemented so so what I like you know in my little world is I can buy a voice over IP server from one manufacturer and I can buy sip phones from other manufacturers so if I want really expensive sip phones I would buy Cisco sip phones if I want really keep sipping phones I would buy Linksys sip phone you know basically whatever my budget allows it is is what what I can afford so this is the protocol it uses sip sip resides on top of tcp/ip this is actually an application of layer networking communication so this can ride on tcp/ip this can ride on UDP this can ride on some other protocol so this is actually it's a networking protocol but it resides above tcp/ip so so sip is the basic communication that all like I say the voice over IP servers use the telephones use et cetera this is how they talk to each other now why I say SIPP is important sip sip sip have you heard me say sip before sip is very important and you should buy systems that use sip as the protocol here's the reason why is because some of the major manufacturers of telephone systems they don't really like open source they don't like open operability if you buy in a via phone system they want you to buy Avaya phones if you buy a Nortel system they want you to buy Nortel phones Avaya doesn't want you to buy in Avaya system and then Cisco phones or in Avaya system in Linksys phones Avaya wants to sell you both the telephone system and all the phones the call box is etc they go with it here's a fine business practice for them but but I hate it the read the way they're able to make this happen is they have their own proprietary protocols that nobody else can use so don't quote me or don't sue me if you're from Avaya but last time I was looking at Avaya phone systems like I say I back in the day I was certified 90 hours of certification on Avaya phone systems I think of aiiah phone systems are just the cat's meow they're they're very high quality they're very basically user friendly etc when I went to buy voice over IP systems for my clients I found out that they only use proprietary protocols now so that kind of killed it for me I've never used in a via phone system again why because if you buy in a via voice over IP PBX or voice over IP server you can only by Avaya phones to communicate with it because Avaya doesn't license out this protocol just willy-nilly again they want you to buy the phone system and the phone's all from them I think that's a bunch of garbage that's the other reason why I was just talking about the gateways and for Skype Skype uses a proprietary protocol so if you use the Skype service you can't go out and buy just any willy-nilly voice over IP phone to connect to the the Skype service that phone has to have the Skype protocol built into it again that's why I like sip lots and lots lots and lots and lots and lots and lots and lots of manufacturers build stuff for sip and like I say I just think it's the future and if you buy something non sip I just think that's kind of dumb the nice part with a sip is what's good for you is a consultant or you as a business person as I've seen this is since cisco deals with sip and open-source voice over IP servers deal with sip I have seen a fellow consultants where what they'll do for clients if it clients want to seem prestigious if they want to seem more important than their bank account actually allows what the consultants will do is they'll go out and they'll buy Cisco sip voice over IP phones and then have those phones connect back to a free open source voice over IP server so it looks like they have this really expensive fancy Cisco system when really although Cisco phones connect back to a little $400 computer sitting in the back broom closet somewhere so this is something that you can do that makes it nice you can have you can have cisco call manager connect to the Linksys phones you have Cisco phones connected to asterisk you know since sip is the networking protocol that allows all these devices and voice over IP servers to communicate you can you can mix and match at will so that that's a very important like I say Nortel Avaya a lot of the old-fashioned telephone manufacturers use proprietary protocols and I'm telling you it's a bad bad bad bad bad bad bad bad idea to use those because um you know you can either have you can either use stuff from everybody or the proprietary stuff now we've talked about all these voice over IP devices and voice over IP server use a protocol to to talk to each other so this isn't tcp/ip this is either sip or as a proprietary Skype protocol or proprietary Avaya protocol but they all use a protocols in order to communicate to the server and to other devices on the network the next thing we need to talk about are the codecs codecs Co Dec if you can't can't read that the codecs this is how the voice traffic is actually encoded and encapsulated so when you're talking on the phone your communication has to get put into little little packets and and sent down the network your codec is what determines how this happens so if you want really really high quality communication voice over IP traffic and you have a lot of bandwidth then you will use a codec that uses a lot of bandwidth and you have high definition audio communication back and forth but let's say you're you're on a kind of a crappy network you don't have a lot of bandwidth on the network your codec is what will determine and you can say I want to use a lesser grade codec where our communication is not going to sound as good but it will use less bandwidth so the main thing with codecs that you have to remember is codecs determine the quality Oh quality so actually I should say sound quality of the conversation so how much static is on the line you know is this high-definition audio communication or is it something that sounds like you're on a CB that is determined by the codec you use and then also the bandwidth that is used for the communication so the codec determines the quality of the sound and then how much bandwidth is being used when you talk to somebody over this voice over IP network so when you pick up the phone and you call Bob in the office of five offices down how much bandwidth is that communication going to take is it going to take ten kilobytes per second is it going to take four kilobytes per second it's all determined by the codec that you're using so this codec is is basically like I said it's what encapsulates and it determines the sound quality and the bandwidth used now most of you if you're dealing with small offices small offices with pretty good networking gear you don't really have to worry too much about the codec so whatever voice over IP server you use will have codecs built in some codecs are proprietary which means you have to pay money in order to use the codec but when you buy your server you will either get a license to use that code a proprietary codec that is there or they will give you open source codecs to use so like I say if you download asterisk or Switchvox or sip X they have open source codecs already built into it so you can just use those codecs for your voice over IP communications no problem the only issue is of course being open source they're not necessarily the best codecs that you can be using so the sound quality is probably going to be pretty good it'll probably be more than what you need but the bandwidth used is going to be more than some of the better proprietary codecs out there so basically whenever you pick up the phone you know the sound quality will be fine but each telephone call is going to take more bandwidth and then necessarily is needed now if you're dealing like I say if you're dealing with a hundred people or a thousand people on a network you have to worry about network congestion because you know if you have a thousand people on a network and 50 people are on a phone all those two little 10 kilobyte per second voiceover voice over IP communications can start taking up a lot of bandwidth so what you should think about is if you're dealing with large networks is you may have to buy a proprietary codec for your voice over IP system normally they run I think they're about $5 per per device they'll be connecting to the network so if you're noticing if you switch over to a voice over IP system and you notice your bandwidth starting to get constricted you may think about having to change your codec hopefully you can change to a free open-source version but if that is still using too much bandwidth you can change to a proprietary codec again you'll probably pay about five dollars per per phone or per device that will be connecting but you can normally get really high quality of communications down to about 4.5 kilobits per second I think is with the good ones use so basically these proprietary product codecs will give you high quality sound with with lower bandwidth so so that's the codecs again codecs this is what encapsulates and decides the sound quality and the bandwidth usage of your voice over IP traffic so we've talked about the protocols now we've talked about the codecs the final thing we need to talk about is network latency and QoS or quality of service now both of these things have talked a lot about in other classes so I'm going to run through them here just because if you're showing up in the beginning of this what will give you the information but but we talked about this much more in many of our other networking classes so the first thing I'll just run through really quick is quality of service again we've talked about this a lot but what this is used for is since you are now using your network not only for computer communications but also for telephone for voice over IP communications you have to be careful that your computers don't use all your network bandwidth because if your computer's start using all your network bandwidth you have no bandwidth left before your telephone system so so you know if one of the dingbats in accounting decides that they're going to download BitTorrent files you know they're going to download pirated movies and they start using all the bandwidth on the network well then when you go to make a phone call you're not going to be able make a phone call or the quality will be very very very poor because all the bandwidth is being used by that idiot and accounting to download BitTorrent files again once you start you know you have a larger and larger company you proportion or your percentage or whatever numbers you get more and more idiots so when you have a 50 person company you probably have one or two idiots you know when you have a hundred person company or five idiots when you a thousand person company you hope you only have 50 idiots I mean that's kind of how it goes so what quality of service does is it allows you to prioritize network traffic so what this means is you go in to your networking equipment so this is your switches and your routers and in the switches and the routers you can prioritize network traffic based on what it is so basically all you do is in the switcher router you say I want voice-over-ip traffic to be much more important than the normal computer communications so what this means is that your switches and your routers will make sure your voiceover IP traffic gets through and it's not so worried about all those computer communications again when you're sending emails or you're downloading files a little bit of delay you don't even notice it if you're if you're talking to somebody on the phone and there's a delay you start getting rid over though I you start getting weird stuff if there is delay so the main thing is you don't want delay on the network that's why you use the quality of service and again like I say it'll prioritize your voice over IP network traffic and basically to make sure everything goes through the next thing that we need to talk about is network latency and this network latency is most important if used aside to use a hosted voice over IP server so the hosted voice over IP server again is you know back in the old days and how a lot of people do it is you would have your PBX or your voice over IP server in the building where you're where you work so you know all your telephones your computers and your voice over IP server we're all in the same building now it is like I say that little voice over IP server can be on the internet and all your your computers and devices etc can connect to that voice over IP server through the Internet well here's the problem you need to make sure your internet network latency is not too high what network latency means is it means the time it takes from when a bit is sent from one place to the next so when somebody starts talking when they say hello how long does it take for those bits to go from that voice over IP server all the way to your building now you may not realize or have ever thought about latency until you start using a voice over IP the reason is is because when you're downloading files you don't really notice how quickly everything happens but when when you're having a communication everything has to happen basically real time so when I start talking as soon as I start talking the person on the other side has to start hearing what I'm saying when they start talking I have to start hearing uh what they're saying if if that doesn't happen we start talking over each other like sometimes I'm sure especially with cell calls you can have a really miserable experience where if the timing is off you start talking over them they start talking over you you don't really know where you are in the conversation why because it takes too long for their words to come from where they're at to where you are so basically the network latency is how long it takes for the bits and bytes to get from point A to point B now a normal telephone call as I understand it looked it up on the internet like Wikipedia has a it has a latency of 45 milliseconds so when you are in a normal phone call with your wife your mother your brother your sister your lover when you start talking it takes 45 milliseconds for your word to get from here to there so whether whether you know your you're talking to them across town or across the country it takes 45 milliseconds for your words together and so that is considered average call quality so 45 milliseconds now in the voice over IP world they're a little a little more lenient about this from what I've seen basically depending on who you talk to you can have 40 to 75 to 100 millisecond delay and still have a relatively okay communication with the person other side so this means when you start talking it takes anywhere between 75 to 100 milliseconds for your words to get from there to there so that's something to just understand keep in mind we're going to have a network troubleshooting class where I'll show you how to figure out your your latency on your internet connection but just understand like I say is if you're using Skype if if you're if you're purchasing a voice over IP service on the internet your network latency is very very very very important because if it is over a hundred milliseconds if it over 100 milliseconds for your words to get from you to the person you're talking to you're going to have an absolute mess I'm sure I'm sure you've had those horrible phone experiences in the past and it's just just miserable like I say the normal standard is considered 45 milliseconds a normal telephone call this is an old-fashioned telephone call as in you have your telephone at your house you call your mom it takes 45 milliseconds to get from point A to point B I say with voice-over-ip before you start having really problems it's somewhere between 75 to 100 milliseconds if you understand how to how to figure out the latency you'll be fine if you don't understand how how to find out this latency liesecke come back for the for the network troubleshooting class and we'll talk about this so now before we go on to the final thoughts you know we've talked about basically everything we need to talk about for voice over IP the final thing that I just kind of want to get into just a little bit though is something called unified communications so you know in the old world we dealt with telephones and then we came to voice over IP so basically as most of us think of it voice over IP is telephones but they use Ethernet and tcp/ip standards well the idea with unified communications is people are sitting down and they're saying well if telephones are now basically computers and telephones can talk to computers and the voice over IP server is a server what else can we do in the computer realm um to make communications easier and to make make communications better and this is where the idea of unified communication comes up so basically what this is is it's kind of turning some of these things on their head and basically giving more functionality for communication so now since you can have a soft phone on your computer the idea is why not install an Outlook plug-in so straight from Outlook you can make a phone call so so let's say somebody emails you a message instead of emailing you emailing them back you can click on their name your computer can now make a call through that voice over IP server when it connects you hear the people or hear the person you're calling through your speakers and you're talking to the person through the little microphone that's sitting on your computer so now your computer is acting as a telephone and not beyond that you're actually calling straight through Outlook so you don't need any additional soft phone software out there or the idea of let's say wow that that conversation is happening you can have Outlook actually transcribe and write down everything that is being said especially a lot of people worried about legal issues you know what what gots it said when did when did it get said you know if you have an audio file it's very hard to go back and dig through all that if all of that gets it gets written into a text file you can do a Google search any time you want to see when things are said so while you're your head in this communication you know the text can be transcribed you've probably already seen with unified communication where if somebody sends you an email you can have that turned into an audio file and sent to you as a voicemail so somebody sends you an email a computer reads it turns it into a sound file and then you get a little voicemail on your telephone you pick it up and it goes you know email from Bob Jones hello it was nice to meet you today that that's a function of unified communication or the idea of you know if you don't want to get bothered with picking up voicemail and such people can call to your voicemail when it when the phone when the when the call gets recorded onto the voicemail system you're now your voice over IP server can turn that audio file into a text file so now you you know you call in you leave a message the computer turns all that into text and then emails it to you so instead of having to call in and get your voicemail you now just get an email sitting in front of you other features that they're talking about is things like instant messaging you know we used to deal with AOL or ICQ and if you wanted to have an audio communication with somebody they would have to be using AOL Instant Messenger or I CQ or such now the idea is you would just have this one instant messenger client and if you want to call somebody to a normal telephone line if you want to call somebody using a different type of system you can just click on them and you'll be able to make that call through these are all the concepts of unified communication like I say right now that this is a conceptual thing this is where we're going to this is where we're moving to the idea is now in the past we talked about before telephones were siloed in their own world computers were siloed in their own world they could talk a little bit they really couldn't talk too much now that we're using voice over IP telephones quote-unquote telephones now reside in the same world that computers reside in so now how can we get them to talk how can we get really cool information to go back and forth and just make life everybody's life easier it's it's a pretty cool concept and it's something something you should keep your eye on so that was a class on introduction to voice or introduction to voice over IP I hope you've been able to follow along with this pretty well again you know as I always say this stuff is relatively simple as long as you understand what's going on we talked about the voice over IP servers so voice over IP servers act like the old telephone system PBX is did well I say they are I call them voice over IP servers because these are computers that provide services to other computers on the network as we talked about with a voice over IP clients every voice over IP client is a full-fledged computer if you knew how to hack it you could probably start playing space invaders you know even on a voice over IP telephone they are all computers you actually configure them by going into a little web server interface that resides on the little telephone of the device it's really true we talked about the hard phone so hard phones are these voice over IP clients that look like phones they look like a telephone but they're really a computer but we call them hard phones because basically they're they're they're they're single-use devices you although there are a computer all you use and for is for telephone calls we then talked about soft phones soft phones are pieces of software you install on to normal computers like a computer a laptop a netbook even an iPhone and that allows you to connect to your voice over IP server and use that computer just like you use a telephone we talked about the gateways so gateways are what'll what connect the voice over IP world to the normal telephone world so like I say is you have normal telephone lines that come in they come in to one side of the Gateway and then your voice over IP connection comes in to the other side of the Gateway if you need to call to the outside world that gateway allows that voice over IP traffic to get to the outside world we talked about the protocols like I say protocols are very important and if I haven't said it enough just remember sip s IP session initiated protocol sip is a standard protocol that lots and lots of manufacturers and vendors use for their voice over IP servers and voice IP clients again you can mix and match devices and servers you can put a cisco voice over IP phone onto an asterisk free open-source tell voice voice over IP telephone server with the other manufacturers like I say Avaya Nortel etc a lot of them use proprietary protocols which means if you buy in a via phone system you have to buy a via phones there's no I I have it's my opinion my opinion I have not seen any quality improvement I mean I've not seen any good argument on why you should stick with one manufacturer it's not like if you buy only from one manufacturer the the equipment is just so amazing I mean all all all the phones and all the voice over IP systems are very good so I would say just just stick with us we talked about the codecs so the codecs are the pieces of software that actually encode your audio communication so this is what determines the sound quality and the bandwidth used when you're on a voice over IP call so when you pick up the phone and when you start talking that codec is what turns your communication into the the packets to get sent off now again when you buy a voice over IP phone system they will come with codecs and normally they're fine like I say they do free open-source phone systems come with free open source codecs and by and large they are fine and therefore you you really shouldn't worry about it if you are noticing bandwidth congestion or if you're noticing other problems there are proprietary codecs that you can purchase and install on to your voice over IP server that have better performance so you know instead of using 10 kilobits per second it'll use 4.5 kilobits per second again most of the time this doesn't matter for especially for small networks but when you're dealing with a hundred or a thousand or 10,000 users that can really matter generally from what I've seen it's about $5 per device or 4 per client for these codecs so so that that's what you're looking at pay for we talked about the network latency and we talked about QoS or quality of service network latency is important especially when you're using a hosted voice over IP service Soul Agency is the put you know how long it takes from a bit to get from where you're at to where it's going so when you're talking to your mom a normal telephone call it is 45 milliseconds from when you start speaking to when she hears it with voice over IP they say somewhere between 75 to 100 milliseconds is okay it's considered good sound quality if you have more than 100 milliseconds in delay between when you start talking and when they hear you you start talking over each other over each other because you start talking they haven't heard you so they start talking I know if you ever used a cell phone you get this every once in a while where there's just a mismatch in the communication so you start talking but they haven't heard of so they start talking over you and then you start talking over them and it's just a mess so this is is Network latency and then you know as we've talked about a lot a lot a lot is QoS quality of service and basically this is that your network packets are prioritized based on what type of traffic they are so you make voice over IP traffic far more important than normal computer traffic and and and you'll be good finally we talked about the overall idea of unified communications so so this is where everything is going since we're now at voice so you know that we now have voice over IP so we have something we're in something called convergence we had a class on convergence so telephones telephones now use the the network the tcp/ip network you can now have computers talking to telephones and audio communication and you can get a bunch of really cool fancy things you can get instant messaging systems that you can make a telephone call through so you know back in the day you could do an instant message audio call where if if you're on you know aim you know AOL Instant Messenger and somebody else is on AOL Instant Messenger you can make an audio call to them well now since its unified through aim or through some instant messaging service you can actually make a call all the way out to the outside world you can call whoever you want if you're sitting in Outlook you can make a call straight through Outlook and the call will be coming you know through computer speakers and you talk into your computer microphone so the idea with unified communications is everything gets unified so again like I says if you're looking at the outlook scenario we all know about inboxes we all know about sent messages etc now imagine if outlook can actually record the phone call that that when you're talking to somebody so when somebody calls you it would automatically record that phone call in a file and keep it in your inbox or if somebody leaves you a voicemail that file will be sitting in your Inbox those are the types of cool things that can be done with unified communications so this is a class on introduction to voice over IP this is the basic high-level concepts of how it works as you know I'm Eli the computer guy it's always it's always fun to teach these classes and look forward to seeing with next one

Channel: Eli the Computer Guy

Views: 1,389,688

Rating: 4.9008741 out of 5

Keywords: introduction, to, voip, 720pH

Id: 2x3Ie6VZ_sg

Length: 61min 20sec (3680 seconds)

Published: Thu Feb 17 2011

Reddit Comments

[u/lirakis]

Eli visited us at OnSIP and we spent a day talking to him about VoIP and our service.

http://www.onsip.com/blog/2012/10/09/onsipcom-and-the-future-of-the-telephone-eli-the-computer-guy