I am a high school student. and I am looking to forward my studies in telecom. my school has VoIP phones. The teacher had a telecom person come and talk to the class about technology. he was using terms like PRI, POTS, DIDs, SRST, ect..
I have a basic understanding that pri is a ISDN T1 connection. my question is how does it all tie together. as far as connecting pots lines to pri and setting up srst for a fail over. I know this site is not for newbies like me. I was hoping someone could help me with how all of this come together in a Voip world.
Thanks
Mike
I know this site is not for newbies like me.
Mike, nothing could be farther from the truth. We are happy to help people learn this industry. You'll soon find that feedback to your post will be followed by plenty of insightful advice.
By the way, you need to work on your capital letters if you want to be taken seriously by professionals. We aren't texting here.
Mike here is a good video that describes SRST. (Survivable Remote Site Telephony) Basically in a centralized call processing model where phones are registering to a cluster at the headquarters, if the sites do not have some sort of redundancy and the WAN link goes down you will not be able to process any calls. What happens with SRST is the phones register with the local IOS router and get their call processing capability from it. All the calls will go out the local H.323 or MGCP gateway & incoming calls will be handled in a way you configure. For incoming calls, I can setup DID translations for a PRI or I can route a voice-port to any extension or group of extensions.
https://www.cisco.com/en/US/products/sw/voicesw/ps2169/index.html
Mike -
When you say "connecting pots lines to a pri" Are you referring to standard single line phones, dial tone circuits from a telephone company or something else?
Sam
Welcome to the board Mike - You're in good hands here. 1 recommendation would be to add as much detail as possible to your questions - That will allow us to provide accurate answers.
Also keep in mind that VoIP is a pretty nebulous umbrella. It covers things that are all over the spectrum. About the only commonality all "VoIP" shares is that it travels across TCP/IP at some point. Everything else is pot luck.
So, to reiterate brace, you need to spend a little more time doing some general research and ask questions with a more narrow focus.
, Mike. Listen to Kumba...he might be on the "darkside" (computer dude) but he does know not only his stuff but telephony also.
This is the guy to listen to, watch, and emulate.
Advise from an old timer. :thumb: :db:
EV607797- I apologize for not using capital letters, yes I do want to be taking seriously that is why I posted questions here for help. I understand the "texting" comment. Since I don't own a cell phone or a computer at home the only time I can post is at school. I am not a "texting" person. I will be taking an advanced Telecommunications class next year as a sophomore in high school. Telecom is what I love and I would like to make it my career. Sounds like I am not ready for you guys yet.
Thanks
Mike
Oh, i beg your pardon, why are you not ready to learn ?
Sounds like to me, you are exactly where you need to be.
Welcome aboard young sir.
Mike, as I mentioned in my initial response to your post, we are here to help you.
My son doesn't know how to communicate other than by texting and his messages are frequently near-impossible to understand. Texting really has taken proper grammar and punctuation down a few notches. That really rubs me the wrong way. I made the assumption that perhaps you were communicating via texting.
Working in the telecom business isn't all about knowing the technology. It's also about being articulate enough to discuss the product with the customer. That was my angle when I made my initial response. It's not just about the business, it's about looking like you know what you are talking about.
Don't be afraid by our responses. We are always willing to help, but we needed to feel you out to make sure that you are sincere in your initial information request.
You won't find a better resource for telecom information than what you will find here. We may not always tell you what you want to hear, but we speak from decades of experience. Even if you disagree with our feedback, rest assured that there is no harm is asking why.
Hey Mike,
As a relative novice to this board, I can assure you these folks will go out of their way to help you any way they can.
Believe me there Mike, people who are hungry to learn are always welcome!
LittleMike,
I agree with Ed. Be mindful of your grammar. Don't take his comments as a beat down, just a friendly bit of advice. It will benefit you in every area of life.
As for the video... I like the subtitles. Nice touch.
It may have just been this fellas accent, but I want to check myself on this... isn't telephony pronounced tel-f-uhny, not tele-fonee.
And while I'm on the subject... It has become apparent to me I need to get with the program myself. Sitting here on this old Avaya G3r (TDM switch) that does not look to be getting an upgrade anytime soon. What steps do I need to take to make myself "IP ready".
I may have asked this question in the past... still it might help LittleMike and some others.
I wouldn't even know where to teach someone how to get into IP telephony. I would imagine you would learn it the same way you did TDM/Digital. You start with the basics (although i'm sure quire a few of you can skip the cabling 101 classes) and then work your way up from the copper/fiber.
So, after the medium comes the Layer 2 and Layer 3 Network. Or basically a simple understanding how TCP/IP communicates and works. You shouldn't need to dig down and reverse engineer the protocol but you should understand the basic concepts such as IP, TCP, UDP, subnets/CIDR, routing, QOS/COS/DSCP, latency, jitter, and for the coup de gras (I.E. last thing ya learn AFTER you understand the other things mentioned) you want to know how to do packet sniffing / wire tap. There are also many other things that can come into play here that can help you but they aren't worth mentioning until you have a basic understanding of the above. Walk before you run so to speak.
Other general areas of study would be network design (logical infrastructure and not cabling per se), Layer 3 managed network protocols, failure/redundancy strategies, bandwidth aggregation, etc. This is where your ability to serve 10 or 100 or 1000 phones on a unified network come into play. Mastery of these will really help you diagnose issues and keep the customer happy.
The last bit is actually the VoIP specific part. You do need to learn about the glorious mess of a protocol they call SIP. You would want to learn it's general use terms, how it operates on your network, how it breaks on the internet, and how to diagnose SIP issues from your switch. With the exception of the "standard" written for SIP, everything else is all determined by your manufacturer. This is usually the part that kills most people as the protocol and it's nebulously written standard almost always result in varying implementations by different manufacturer's. All I can really tell you here is learn how it's supposed to work, then figure out what makes it work. That's about the same as some TDM/Digital systems anyways so it should be old-hat for most of you.
So, that's my $0.02 on how to get into VoIP or IP Telephony or whatever they are calling it this week. And as always your mileage may vary.
Welcome, Mike. I think you found yourself the right place to learn, stick around.
In your first post you mentioned a "voip world". This is not exactly true, though some marketing departments would like you to believe it's inevitable. As far as telecomms is concerned though it definitely is, and has been for decades now, a digital world.
Voip is the latest attempt to bring a commonly agreed open standard to the end user's station. It happened that the overall transport protocol chosen (IP) and its more voip-specific sub-protocols such as RTP was/is in the public domain, and is also packet-based. The digital schemes already in use, use transport protocols (T-Carrier/E-Carrier) that are switching circuits rather than packets.
SIP is the signaling protocol used by many (not all) Voip implementations. The rather complicated and proprietary counterparts in so-called "traditional" telecoms, such as SS7, remain in what computer people used to call "big iron": elaborate switching/routing computers in special facilities.
Then you have the issue of the media codecs, the hardware (or these days, most likely software) that translates 0s and 1s - whether they travel in packets or riding on circuits - into voice: traditional digital telecoms as a rule, use a collection of codecs known as G.711. There are many more options in the various voip implementations, though in the end, most end up using RTAudio codecs in some form or other.
So there's something of a big picture. By all means, take it further.
Probably your best bet is to look for a telecom union and see if they offer a training class/program. The only other thing I can think of is getting hired on by an interconnect.
I'm pretty sure that you wont be doing just VoIP any route you go. I would venture to say I am one of the closest people to "VoIP only" work on this board and I probably still spend probably 20-30% of my trouble shooting and install time debugging T1's and D-Channels.
D-Channels. You will learn to hate them. At least on some carriers
You can also browse here:
voip protocols
Sounds like you need a single source for translating the "acronym speak" that is common in telecom and IT. After multiple translation requests, I have purchased this book "Newton's Telecom Dictionary"
https://www.harrynewton.com/ for a couple of friends of mine who were in positions in which they had to interact with IT/Telecom tech types.
Not an in depth source, but good for a quickie overview.
Welcome Mike!! We REALLY like people who come here to learn, we also learn from you folks as well as each other.
By the way, don't let ANYONE try to send you out for a bucket of dial tone or a cable stretcher!!!
But can you go get me some fiber bridge clips?
Hey Mike! Welcome.
My suggestion, start at the bottom dude, it sucks but it's a start. By that I mean start at layer 1, your physical connections, learn how to wire jacks for single line phones, RJ-45 connections, pin layouts for T-1 lines, RS-232 connections and so on. Some of this is no longer used but your understanding of how things work and communicate will expand greatly and make you that much more valuable.
A couple things, POTS (Plain Old Telephone Service) line, this is just a telephone line from your telco (telephone company). You can start moving into the layer 2 as well, learning about protocols, networking, switches, hubs and much more.
Look at your questions this way for now, a PRI T-1 comes from your telco and into your network. Than you have phones or extensions that use that PRI to make incoming/outgoing calls on. You can do this on a POTS as well but a POTS is just one phone line, not 23 like a T-1 PRI.
SRST-in short is a survivability term so if you lose a connection from a router back to your phone system or Call Managers (referring to Cisco here), the router takes over and keeps a certain number of phones working (depending on your router size will determine how many phones can still function). Than on the router you might have a T-1 or just a few FXO (or pots lines) for incoming and outgoing. In srst mode you dont' have the full functionality as if connected all the way back but enough to answer/make calls and transfer until the connection is restored.
DID's are basically direct lines to an extension, a voicemail or a hunt group. Say you order a T-1 line and need a block of 50 DID's, the phone company will assign you say xxx-5000 to xxx-5049 so than you can program your system to have xxx-5000 ring whatever extension and so on.
Cisco has moved to a Linux OS for their newer call managers, so obviously the more you can learn the better.
Linux would be great, but even better, become a genius with routers and switches as well. The actual voice side is not too hard to get, once you learn the terms and how trunk groups, hunt groups, pilot numbers, routing patterns, calling search spaces, partitions, and so on interact and function with everything else.
Any other questions just let me know and I'll try to help you out! Good luck.
Its nice to see some fresh young blood here. I was worried that the telecom industry is turning into a country full of old men.