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Full Discussion: Modems still in operation?
The Lounge What is on Your Mind? Modems still in operation? Post 302510316 by Neo on Sunday 3rd of April 2011 12:11:05 AM
Old 04-03-2011
FYI only, on ATMs, POS machines and modems:

Ref: US Robotics on Modems and POS

Quote:
Modems allow the PoS computer to communicate with the banks or credit card processing centers to get the transaction approval. The modem also allows daily transaction totals to be sent to other locations within the company such as corporate headquarters. Modems can be embedded within the PoS computer system or can be attached externally to the PC.

Many systems use LANs or Local Area Networks to transfer the data locally via an Ethernet cable instead of using dialup modems. This type of connection is ideal for systems that have multiple computers that need to access the same information such as restaurants, but ultimately the call for card approvals is still sent via a dialup modem
.

Quote:
So why still use dialup?

There are 3 reasons to still use dialup modems: minimal data and speed requirements, cost associated with setup, and security of a on demand connection.

Most current modems transfer data up to 56 Kbps, but the PoS systems don’t always require those kinds of speeds. Transactions are normally quite small and may only require 300 bps up to 2.4 Kbps – only a fraction of what normal dialup modems can support, so 33.6 Kbps modems can be used with no loss of time. The 56K modem connection allows some of the more sophisticated PoS systems to transfer more data and utilize the faster connection speeds.

With these small amounts of data and minimal speeds needed, the faster Ethernet networks are not needed and the dialup solution can be much cheaper to implement. Most businesses need to be able to accept card transactions, and installation of a simple dialup PoS terminal may only require a dedicated telephone line, whereas installing a network and paying for business quality broadband service could be quite expensive to set up as well as the higher fees each month. In addition the nightly transaction summaries sent out can be scheduled during off peak hours which can also save even more money.

Connecting only when you need to also insures better security. The “always on” broadband connection means the computer and PoS system is constantly connected to the Internet with makes hacking and security breaches a higher threat. With dialup the computer is only connecting to the Internet just long enough to complete the transaction, making hacking into the terminal very difficult.
The same POS arguements above are also true for many of the ATM machines we see all over Asia in gas stations, small grocery stores, etc. Almost all of these use dedicated phone lines and modems.
 

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FAXMODEM(8)						      System Manager's Manual						       FAXMODEM(8)

NAME
faxmodem - dynamically add a modem to a HylaFAX server system SYNOPSIS
/usr/sbin/faxmodem [ -q queue-dir ] [ -c capabilities ] [ -p ] [ -P ] [ -u priority ] modem DESCRIPTION
faxmodem sends a message to the HylaFAX queuer process faxq(8) telling it that the specified modem is ready for use and informing it about its fax-related capabilities. This is the mechanism by which modems are added in a send-only configuration. Once a modem has been config- ured its status can be reconfigured using the faxstate(8) program. faxmodem can also be used to alter the capabilities and usage priority of a previously configured modem. The specified modem is either the terminal device name where the modem is attached or a HylaFAX device identifier (see hylafax-config(5) for information on device identifiers). Device names may be given without a leading directory pathname; e.g. ttyf2 instead of /dev/ttyf2. To figure out the capabilities of a modem either use the probemodem(8) script or manually communicate with the modem. For a Class 2 modem the capabilities are given in the response to the ``AT+FDCC=?'' query command and for a Class 2.0 modem the ``AT+FCC=?'' command. To check if a modem is capable of polled retrieval of documents use ``AT+FSP=?'' for a Class 2.0 modem or ``AT+FSPL=?'' for a Class 2 modem; if ``1'' is indicated in the response then the modem supports polling. For example, hyla% cu -l ttyf2 Connected at+fclass=2.0 OK at+fcc=? (0,1),(0-5),(0-2),(0-2),0,0,0,(0-7) OK at+fsp=? (0,1) OK In this case the modem would be added using the command: /usr/sbin/faxmodem -c '(0,1),(0-5),(0-2),(0-2),0,0,0,(0-7)' ttyf2 (by default polling is assumed to be supported). Class 1 modems require a different technique. The host implements most of the fax protocol so all that is needed is to identify the possi- ble signalling rates the modem supports for transmitting; this is done with the ``AT+FTM=?'' command. For example, hyla% cu -l ttyf2 Connected at+fclass=1 OK at+ftm=? 24,48,72,73,74,96,97,98,121,122,145,146 OK In this case the modem supports 2400, 4800, 7200, 9600, 12200, and 14400 bps signalling rates so the modem would be added using: /usr/sbin/faxmodem -c '(0,1),(0-5),(0-2),(0-2),(0,1),0,0,(0-7)' ttyf2 OPTIONS
The following options are available: -c Specify the fax capabilities using the syntax defined by the ``Class 2'' specification: ``(vr),(br),(wd),(ln),(df),(ec),(bf),(st)''. where, vr specifies vertical resolution, br specifies bit rate, wd specifies page width, ln specifies page length, df specifies data compression, ec specifies error correction, bf specifies binary file transfer, and st specifies scan time/line; and each of the above specifications is a range or list of numbers that defines the exact capa- bilities of the modem. For example, the default capabilities are ``(0,1),(0-3),(0-4),(0-2),(0),(0),(0),(0-7)'' which specifies the modem is capable of sending and receiving both low and high resolution facsimile with a variety of page sizes; supports sig- nalling rates 0-3 (2400 bps through 9600 bps); supports only 1D-encoded data compression; and does not support error correction or binary file transfer. A modem's ability to support polled retrieval of facsimile is specified separately with the -p and -P options. -p Specify the modem is not capable of polling for remote documents. -P Specify the modem is capable of polling for remote documents (default). -q dir Use a spooling area other than /var/spool/hylafax. -u priority Assign the specified priority to the modem when scheduling it for outbound use. Modem priorities are numbers in the range [0..255] with lower numbers meaning higher priority. Modems are initially assigned priority 255. FILES
/var/spool/hylafax default spooling area /var/spool/hylafax/FIFO fifo for contacting faxq Consult hylafax-server(5) for a complete discussion of the structure and content of the spooling area. SEE ALSO
hylafax-server(5), faxgetty(8), faxq(8). Oct 27, 1995 FAXMODEM(8)
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