What kind of remote modem ?

Hi Expert
Can I know what protocols (K56Flex, V90, X2)are supported by the modem which I connect to ?
Can I send any AT command to the remote modem ?
Thank you in advance

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You have to ask the other side, what modem are they using? What software are you using to send AT commands?
K56Flex and X2 are the so-called 'proprietary' protocols by Motorola (I think) and USRobotics respectively, when, during the time that 56K speed isn't an ITU-T certified standard. Or you can call it the developmental stage name for today's ITU-T v90 protocol.

I doubt it if you can still find x2 modems on the retail store. Or even K56Flex without v90. Even the old K56 and x2 modems are now or have been upgraded to v90... but of course, depending on the particular brand you're going to buy, ex 3com modems have x2 in their available protocols together with v90.

Either which one you choose, it's most definitely come with v90 as the primary protocol to ensure seamless compatibility across platforms, and v90 *IS* the final product that comes with bug fixes, enhancements etc.

In my opinion, I'd go for 3Com/USR modems. Specifically for 3Com corporate modems (The Courier(tm) modem line). It may look ugly, may not offer voice capability, etc... but it is one reliable product. Get the external one. Internal modems robs your system of much needed powersupply, and contributes tremendously to system heat thus causing OVERALL system instability.

Errr your ISP definitely supports V90... it's bad for their business not to support V90...
> internal modems robs your system of much-needed powersupply,

Nonsense.  Modems are "electronic" units, and take very little wattage.

It's the motors inside the hard-drive(s) and CD-ROMs and CD-writers and diskette-drives which require the high-wattage.

> and contributes tremendously to system heat ...

Tremendously?  Nonsense.  Modems run "cool".
It's the heat coming off the CPU, and from those motors, which generates 95% of the heat.

> Can I know what protocols (K56Flex, V90, X2) are supported by the modem which I connect to ?

Unless you tell your modem otherwise,
it will attempt to connect at V.90;
if the remote-modem doesn't support V.90, then your modem will try either X2 or K56Flex protocol.
If the remote-modem does not support X2 (or K56Flex) protocol, then your modem will try V.34 (up to 33600 baud).

Eventually, your modem will issue something like:

   CONNECT sssss/www/xxx/yyy/

where 'xxx' is either 'X2' or '56K' or 'V90' or ...

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>Nonsense.  Modems are "electronic" units, and take very little wattage.

Yeah. I agree... and being electronics, also means that they need precise voltage/power requirements. A USB videocam whose rating is 0.5amps needs at least 0.5amps... and any deviation would mean an erratically functioning 'electronic' piece of equipment.

Have we paused for a second as to compute how much more available amperes we have left? What if the guy decided later on that he needs to upgrade his HD to say 20GB?? And his powersupply lacks 0.5amps which incidentally has been allocated to that internal modem? Then in order to keep the modem and be able to upgrade, he needs to buy a new powersupply or opt for a cheaper alternative, that is to buy a new external modem. A dime saved, is a dime in your pocket.

>Tremendously?  Nonsense.  Modems run "cool". It's the heat coming off the CPU, and from those motors, which generates 95% of the heat.

My flourescent light runs 'cool' as compared to the CPU running 350mhz... Coz I can't fry an egg on my flourescent lamp.

Compare the modem to the CPU, it runs a little cooler. But multiple chips emitting heat will definitely heat up the system much faster. Have you ever tried of touching the modem's core chip? An external modem's core chip at that? Run it 1 hour at v90 connect and transfer a file big enough to consume 45 minutes... and stick your finger on it, and try to keep it there for at least 30 secs... let's see if you can hold it for 30 secs. Now an external modem generates heat all by itself... imagine if it's inside a case with the CPU and the BX chipset with it.
> Have we paused for a second as to compute how much more available amperes we have left?

Shall we?  My power-supply has a 5.0 ampere fuse on the AC-power side.

Thus, you can only run ten of your '0.5'-rated video-cameras.  Sorry.

Have you paused to consider that accelerating a hard-drive, from zero to 5400 or 7200 RPM, draws a large current, but keeping that drive spinning takes very *LITTLE* power?

>  his powersupply lacks 0.5amps which incidentally has been allocated to that internal modem?

Since a modem isn't used while booting-up your computer, there should be lots of wattage "left-over" for when the modem is needed.

Ok, sorry for dragging the thread from modem queries to theory of electricity.

Borgo, I have cited my opinion. Of course, you must decide for yourself. So, to wrap things up, of course, in my honest opinion and based on my personal preferences, here are the things that I took into consideration when I bought my modems:



1. Has a seperate external power supply;
2. Plugs into a free RS232c port;
3. Ease of access (eg ser. #s, model, DIP switches, ease of sending it out for servicing, ease of diagnosing, etc.)
4. A hardware based speaker control; (especially important when your modem is slowing down, so that u can hear if your modem is retraining thus telling you the lines are noisy.)
5. Highly visible indicator leds; (if sending or receiving etc)
6. Doesn't contribute to system heat;
7. Doesn't occupy an ISA/PCI slot; so you can expand your system or use it for other purposes;
8. Minimizes device conflicts;
9. Handling is much easier, compared to internal wherein you should think about static electricity, environmental damage etc.;
10. Adds yet another equipment for me to brag about. Hehe


1. Requires desktop space;
2. Requires a free RS232c port;
3. A little expensive than the internal ones;



1. Doesn't clutter your desktop;
2. Doesn't require space;
3. A little cheaper than external modems;


Reverse all the Pros of the external modem I mentioned above, but exclude #10 of course since #10 is meant to lighten up things. Hehe

borgoAuthor Commented:
Thank you Femson, Otta and Iwin for your answer. Now I know a little more about pros and cons of modem.

Please Otta reply for points.

Greetings from Italy to all of you.


To award the points to OTTA you can just click on his comment, and accept comment as an answer.

Tried to read the entire thread to find out as to why it wound up with internals and externals. And found that while explaining the protocols in my first comment, I cited the modem hardwares too. As I was under the impression that you were going to buy a modem... hmmm now where did I get that idea? Hahaha...

Thanks... :P

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Happy holidays.
borgoAuthor Commented:
Thank you Femson

Have a nice day.

Hey! Thanks to you as well. It's nice to know that even if I easily get confused, and have a tendency to talk a lot, (which I hope you don't mind...) I was able to be of help.


Happy Holidays to you, from S.E. Asia, Manila, Philippines!
>> Please Otta reply for points.
> Accepted Answer From: femson7

Yikes!  Otta snoozed, and Otta losed!

> Can I know what protocols (K56Flex,
> V90, X2)are supported by the modem
> which I connect to ?

If you are connecting to a friend's modem, then the maximum-speed will be 33600 -- because two modems cannot make an X2 or K56Flex or V.90 connection between them.

Otherwise, ask your ISP what they support (X2 or K56Flex or V.90 or X2/V.90 or K56Flex/V.90),
or look at the 'CONNECT xxxxx/yyy/zzz' string -- the 'xxxxx' will be the actual speed, and 'yyy' could be 'V90'.
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