56K Modem Information

Requirements
All protocols assume the phone line is part of a modern Public Switched Telephone Network (PSTN), which most areas now have. The protocols work by taking advantage of the digital connections that ISPs like Texas.Net use to connect to the PSTN. Typically, the only analog connection between your modem and Texas.Net is the one between your home and the phone's switching office. If there is more than one analog-to-digital conversion in the loop from your house to the ISP (if the phone company has some extra analog switch), then neither protocol will achieve the increased performance.

Phone Lines
The X2, K56Flex, and v.90 protocols depend on high quality phone lines between your modem and the local phone company's digital switch. Any noise on this portion of the lines will result in deteriorated performance. This 'noise' is not necessarily audible sound. All phone lines carry some degree of 'noise'.

Unfortunately, local telephone companies offer no guarantee of line quality, where data communications are involved. The 'official' policy, depending on who you talk to at the phone company, is that they only support something between 2.4K and 9.6K connections. Some of our customers have reported that they have contacted the local phone company and requested a "data line conditioning kit", which is something installed at the phone company's switch, and has improved their connection. Other customers have requested this and been told it doesn't exist.

If you suspect that line noise might be giving you problems with your connection, Texas.Net recommends that you do try contacting your local telephone company. If you hear any audible noise on the phone line, they should take measures to eliminate that. The phone company seems to also respond better if they get reports of problems sending faxes.

Checking Your Lines
Texas.Net recommends that all customers check their phone lines before they purchase a 56K modem since not all phone lines will support them. To do so, simply use a 28.8K or 33.6K modem to dial the US Robotics test line with a standard terminal program (eg. Windows Terminal, Windows 95/98 HyperTerminal, Macintosh MacComCenter). Follow the instructions at 3Com/US Robotics' web site. Then you should receive a response as to whether or not your line is 56k capable. Please note that this line test will not work if done with a 14.4K modem, and will return false 'positives' with a 56K modem.

Alternatively, if you have a Courier V.Everything modem, you can open up a communications program and type ati11. If you see a line that says Multiple CODECs, your line is not 56k-capable. We're not sure yet whether this works with other US Robotics modems. If you have a Sportster class modem and get this message, please e-mail helpdesk@texas.net.

About 56K Modems and Connect Speeds By FCC regulation, the 56k modems cannot connect above 53K. A full 56K is theoretically possible, but we have not been able to verify that any of our customers have reached this speed. Our experience is that most connections made with 56K modems will be in the range of 40K to 50K.

If you use Windows 95/98, Dialup Networking will report either an initial connect speed or a port speed. Neither of these are particularly meaningful. Both 56K protocols continually 'renegotiate' the connection, adjusting the current speed up or down to compensate for line conditions, which do not remain constant. The new speed is not reported through Win95 Dialup Networking (or most other operating systems).

The true test of a connection is the actual data transfer rate. This can be checked by downloading a large file from a Texas.Net server, timing the download, and calculating the rate. This can be accomplished by going to our software page and downloading the Macintosh install disks with your web browser. All files are about 2.0 megabytes (simply discard the files when finished). What works even better, is to open an FTP program, connect to rsuftp.texas.net, change to the /pub directory, then download the file msie302r.exe. The WS_FTP will report a current transfer rate in Kbps (kilobits per second).

Unstable Connections and Poor Transfer Speeds
Modem manufacturers were very eager to get their new high speed modems on the market. Both the X2 and the K56Flex modems were initially released in a very problematic state. Both offered unstable connections and put transfer rates. Almost all modem manufacturers now have firmware upgrades available for these early versions to upgrade them to v.90. Check our Modems Page for details on checking 56K modem versions.

If you have any questions about this information, please call one of our offices or fill out a Trouble Ticket.