Advice on setting an ISP w/ Linux

I'm planning to setup a small ISP with Linux, I'm looking in using ISDN BRI 64k for my starting.

My question is, is it possible to use a ISDN modem connecting to a Linux box and use the pppd to do the routing instead of buying a ISDN router? What's the advantage if i spend more bucks to buy a ISDN router instead of using a direct ISDN modem.

Please give me some more advice on using which hardware combination. How about the 56K DDS ?
I want to compare the price and it's the main concern for me.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

You do not need an ISDN router when using LINUX. It has the capability of doing all the routing necessary by itself for an entire network.  Only if you want to be operational for your network independent of the LINUX box would you consider a router.

There is a wealth of information about setting up your LINUX system as an ISP and/or router at the web site.

You should do some financial analysis of a 56K (or greater) DDS service vs. ISDN.  In most locations, ISDN is metered.  As an ISP, you will likely be connected 100% of the time.  Around here, "24x7" ISDN connections cost about 10X what a 56K DDS line costs from the telco.  Even a full T1 is less expensive by the month than ISDN if you go full time. There are many options and service levels available.  Be sure you pick one that meets your needs for both bandwidth and cost.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
apn090997Author Commented:
Thanks for your comment first, it's pretty useful to me.

The situation is a little bit different in your site (I suppose u are in States), I'm in Hong Kong. In here, the ISDN(permanent connection, not charge on base on connection time)  is almost the same cost as a 56K DDS. But when I read the book, both of them are 56K in theory.

This is what annoy me, but i think i should choose the ISDN, since i think it can be easy upgradable (still got another B channel to use), also the equipment for ISDN is cheaper ??

Any good ISDN modem recommend ? I got no clue to start.

Ah, it must be nice to have a telco that even knows what ISDN is.  Around here, it's almost impossible to get an ISDN and once you get one, you pay dearly for it...  I've heard good things about the 3COM ISDN equipment, especially their customer support for getting things configured.  I don't know how their distributor in Hong Kong is, so you might want to ask around.

As far as your point about the equipment for 56K DDS being more expensive than ISDN, you are probably right except that there is a lot 56K type equipment on the used equipment market these days.  I recently purchased a Telebit Netblazer 56K router and a Cray 3080 56K CSU/DSU for less than US$100 total.  
apn090997Author Commented:
Thanks for your comment I've take the 3Com Impact IQ as my first choice.

But, my ISP told me I CANNOT use an ISDN modem to do the in-bound routing. According to he said. Modem cannot act as a bridge while only an ISDN router can do it.

He explained to me that if there is a packet came in from their side, my software would definetly try to assign a IP to the call. While a router is born to have the ability to router the inbound traffic without trying to assign any.

He said it's impossible to have software configed to act as a router. BUT I really don't think so. Please advice. I don't think Linux is lack of these kind of flexibility.

I don't the the specific capabilities of the 3COM Impact but...

The statement: "'s impossible to have software configed to act as a router" is completly incorrect.  Hearing this from someone would cause me to be suspicious of ANYTHING else they said.  Of course software can act as a router.  That's what a "router" is.  Software running on dedicated and specialized hardware.  There is even a version of LINUX that boots from a floppy disk and does NOTHING ELSE but be a router.  I'd look for another ISP or someone else at that ISP who knows what they are talking about.  You might also check with 3COM and get their opinion as to the suitability of this device for your intended purpose.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Linux Networking

From novice to tech pro — start learning today.