WAN options

syntacticalerror

Whats going on with all these protocols?!!......haha......no need to answer that. Anyway, someone please clarify the point of ISDN technology. Why would i need ISDN when my cable internet is as fast as T1 and 1/8 the cost?...........yea yea, T1 has 23 bearer channels, does that mean the CIR is for each channel, so the cumulative speed is (CIR x sending channels)?? And yea its a dedicated leased liine, so is it independent of the frame relay or ATM backbone?....if so, is IDSN its own backbone? Obviously there is a need for T1, so whats the advantage? Thanks

networker050184

What happens when your T1 goes down? Wouldn't it be nice to have a dial on demand ISDN line there so you can still reach your devices?

syntacticalerror

i dont' think u understand my questions..........according to sources, such as the cisco press books, T1 is an isdn technology. In fact, its a PRI not the BRI like a dial-up isdn. please don't respond just to get a post credit.

Cessation

syntacticalerror wrote:

i dont' think u understand my questions..........according to sources, such as the cisco press books, T1 is an isdn technology. In fact, its a PRI not the BRI like a dial-up isdn. please don't respond just to get a post credit.

Woo! Post credits for everyone!

networker050184

syntacticalerror wrote:

i dont' think u understand my questions..........according to sources, such as the cisco press books, T1 is an isdn technology. In fact, its a PRI not the BRI like a dial-up isdn. please don't respond just to get a post credit.

Give me a break. I don't need a post credit. If you ask a question expect an answer even if its not the one you want. If you want to know the exact answer read the book like the rest of us did.

The ISDN is used as dial in back up through the PSTN. Happy with that answer?

syntacticalerror

HA, at leaset your not trying to answer my Qs. Credit for me tooooooo.

Netstudent

WHen you are learning things out of a book, you need to realize that things can be different in the real world. So when you are referring to something out of a book, it;s good to listen to people who ahve experience.

syntacticalerror

so you read the books and still cannot answer my Qs?......ur just as lost as me then. HA, and you just looked that one up huh.....mmm. Still doesn't answer my questions tho, thanks for the effort.

networker050184

What is your issue?

Anyway, someone please clarify the point of ISDN technology. Why would i need ISDN when my cable internet is as fast as T1 and 1/8 the cost?...........

Thats the answer. ISDN dial on deman circut would be used for back up or remote access. And trust me I didn't just look it up. I have actually used the technologies you just read about and some day hope to use. If you don't like my answer fine, you are entitled to your opinion, but you don't need to respond with imature remarks.

syntacticalerror

thanks Netstudent, i understand what ur saying, and of course i'm open to people's experiences. But saying isdn (wrong) is a backup when T1 goes down didn't really clarify anything. Obviously terminology is always an issue in the tech world, i'm going to pick on it, but at least stay relevant to my Qs.

Cessation

syntacticalerror wrote:

thanks Netstudent, i understand what ur saying, and of course i'm open to people's experiences. But saying isdn (wrong) is a backup when T1 goes down didn't really clarify anything. Obviously terminology is always an issue in the tech world, i'm going to pick on it, but at least stay relevant to my Qs.

"But saying isdn (RIGHT) is a backup when T1 goes down DOES really clarify EVERYthing"

Another Post Credit for ME !

syntacticalerror

seriously, i appreciate the attempt Networker and i hope you don't have a bad morning cuz of me. i'm just trying to understand where T1 fits into the WAN technologies and why we need it.

Cessation

syntacticalerror wrote:

seriously, i appreciate the attempt Networker and i hope you don't have a bad morning cuz of me. i'm just trying to understand where T1 fits into the WAN technologies and why we need it.

Really?
It almost seems like you have found the answer (especially from this forum) but just wont accept it.
Remember that you can always check with Cisco for anything you are confused with.

networker050184

On a serious note syntacticalerror, a T1 can be used for multiple purposes. Data, voice or both. Its kind of a vauge question. It was developed for voice use, but was adapted for data purposes as well.

hectorjhrdz

a moderator is required here!!!





yep,I only did this for another POST CREDIT!!!! lol

syntacticalerror

so i'm going to pay $350/mo T1 for backup connection, haha, there are different types of isdn lines, and T1 (U.S) is one of them. fine fine isdn dialup can be used for backup, but why is T1 needed when cable internet is cheaper?....sigh** Since isdn uses protocols that cover layers 1-3, does that mean it would NOT be on a frame relay or ATM network, since they are both reside on layer2?


So answer me Cessation, since your a ccna student like i am, are you just accepting what people tell you, or u really trying to understand the curriculum? i think the problem here is i'm asking Qs beyond the scope of the ccna.

Netstudent

HAHA don't flatter yourself! I assure you, you are not asking questions beyong the scope of the CCNA. You are asking questions that are so vague, that nobody can give you a proper asnwer. Cable internet is totally different technology than a T1. Cable internet is a broadband connection, a T1 is a dedicated point to point channelized digital circuit. A t1 has many applications. There are a thousand reasons why you would use a T1 over a cable internet connection.

I understand that you are kinda new and you may be kinda mixed up here. Try to read and do some research on these different technologies. Good luck.

hectorjhrdz

cable internet?


Cable internet it's like when you're are using a hub for your computer network. the more users you attach to the network, the less bandwidth available.

With a leased line you have your bw only for you. it is not shared with other users like cable internet.

sprkymrk

syntacticalerror wrote:

i think the problem here is i'm asking Qs beyond the scope of the ccna.

No, the problem here is that instead of simply asking for clarification or further help, you alienated everyone from even wanting to help you with your smart-alec responses. I am surprised networker050184 even bothered to continue dialogue with you after your insults.
That's a good way to get banned.

BTW - Wikipedia has a pretty nice explanation of Consumer and industry perspectives on ISDN that may actually be the answer you are looking for since you mention cost vs speed.

http://en.wikipedia.org/wiki/Integrated_Services_Digital_Network

tmartino

Didn't they remove ISDN from the new CCNA test, anyways?

syntacticalerror

omg, fine fine its "dedicated", like i said i my original post, and alrite it can suppott voice, data, etc........thanks for clarifying, two Qs down.........next Q from my original post.......is T1 an independent network from a frame relay and ATM network?.........the reason i'm asking is bc T1 has a different protocol at layer 2 then frame relay and ATM........

syntacticalerror

thanks sprkymrk, i just expected a comprehensive answer to my Qs, i won't ask so many Qs next time. Anyway, apologies for the offended and thanks for the efforts.

sprkymrk

syntacticalerror wrote:

thanks sprkymrk, i just expected a comprehensive answer to my Qs, i won't ask so many Qs next time. Anyway, apologies for the offended and thanks for the efforts.

Sometimes someone will give very detailed and comprehensive answers. Other times, you'll get a short answer and some good back and forth dialogue. It's best to remain polite and not get frustrated as none of us here get paid to help out, we do it because we enjoy it and we all learn from each other.

khristov

First do not confuse CIR with the clocking interface speed. You may have 1.544Mbps interface speed but your CIR may be lower (The CIR is the sum of all VCs speed which you would "commit" under normal operations).
Although T1 CAS (Channel Associated Signalling) is slower in signalling if we talk about voice you have full 24 channels available insted of 23 as in PRI (which is now actually SS7 standart, also called nonassociated signaling).
There are still many advantages using these type of connection these days. For example multiservice if you have customer which needs both voice and data, and have already TDM equipment for voice this scenario fits well. You can just setup fractional T1 or E1 and you are ready to go.
By mean "dedicated" we mean that you have reserved timeslosts and they are yours. If you want to transmit something it's fine. If you don't they cannot be used by someone else.
This is especially true if you want to buy T1/E1 end to end between your offices.
You are leasing a line from your office to your provider's telcom equipment. There your T1 is multiplexed into higher level signal and transmitted to the remote telco equipment where it is demultiplexed. So the provider is reserving for you certain timeslots, your connection is really dedicated and you have full multiservice and to end. This is of course not cheap solution but still very companies prefer these type of lines insted of non-TDM connections( not only T1 but STM1/OC3 and above also).

mikej412

syntacticalerror wrote:

i just expected a comprehensive answer to my Qs, i won't ask so many Qs next time. Anyway, apologies for the offended and thanks for the efforts.

You can find your comprehensive answer to any of your questions here