There are a number of factors which can hinder or outright prevent you from getting a 56K (X2, K56flex, V.90, or V.92) connection:
- Your modem is using an older driver or firmware or is not installed correctly, especially if the modem is sharing an IRQ (most Windows systems do not properly handle IRQ sharing with modems!). Visit our Analog Faxmodem Support Files to download the latest files for your modem.
- If you have over a certain degree of interference or line noise on your phone lines (i.e., line noise as it affects data calls, not voice calls -- voice calls are notably less sensitive to being hindered by line noise than data calls are), this will cut back what connect speeds you achieve. Higher-speed connections are more affected by line noise than lower-speed connections. Call waiting and caller ID can also cause problems with modems.
- Your dialing location must be located within 3.5 miles of your local phone company's switching office. Even if you are WITHIN 3.5 miles of the switching office, you may or may not achieve 56K-range (34,000 - 53,333 bps) connect speeds -- but you certainly never will being over 3.5 miles from the switching office.
- There could be server problems or other issues on your ISP's end (i.e., it could be the firmware version that the ISP is using, it could be server setup problems or malfunctions on their end, it is could be that the ISP's servers respond better to certain modem chipsets (Rockwell/Conexant vs. Lucent vs. Texas Instruments [TI]) than other chipsets).
- Somewhat related to #4, your connect speed results may vary with the namebrand of remote access servers (e.g., Cisco, Lucent Livingston, Ascend, 3Com) your ISP uses, what model (e.g., USR/3Com Total Control, Livingston PortMaster 3, Ascend Max), and what firmware version they have at the moment. And, as stated in #4, some servers may respond better to certain modem chipsets (Rockwell/Conexant vs. Lucent vs. Texas Instruments [TI]) than to other modem chipsets (this might vary with what firmware version both ends of the connection are using).
- Of course, depending on what 56K protocols your modem supports (K56Flex-only, Dualmode K56Flex-V.90, V.90-only, or Dualmode V.90-V.92). We have only made K56Flex-only modems (which can be flash-upgraded to become V.90-only modems), Dualmode K56Flex-V.90 modems, and Dualmode V.90-V.92 modems (which handle both protocols). Dialing into an X2-only or V.34 server with your modem will not achieve any faster than 33.6 and, if your ISP supports V.90 but there are problems with your ISP's implementation of V.90 and they have Dualmode X2-V.90 servers, the modem can't fallback on K56Flex mode (being that the ISP's server is not Dualmode K56Flex-V.90 but rather Dualmode X2-V.90) -- so the modem will have no choice but to fallback to V.34 or lower rates. Then Rockwell/Conexant-chipset Dualmode modems (depending upon when you got your modem or if you are using the latest driver and firmware or not), by default, first tried to connect in K56Flex mode before V.90 mode (so if the ISP's servers did not support K56Flex, then such modems have no choice but to connect at V.34 or lower rates -- even your the other environmental factors were favorable to getting 56K-range connections); if your ISP doesn't support K56Flex but supports V.90, you have to explicitly tell the modem to operate in V.90 mode to have any chance of achieving 56K-range connect speeds. Then Lucent-chipset Dualmode modems, by default, first try to connect in V.90 mode and then K56Flex mode (so if the ISP's servers do not support V.90 but are X2-only, the modem will have no choice but to fallback to V.34 or lower rates; or if they support V.90 but there are problems with your ISP's implementation of V.90 and they have Dualmode X2-V.90 servers, such servers do not support K56flex, so the modem can't use K56Flex mode with such a server and therefore the modem will have no choice but to fallback to V.34 or lower rates -- even your the other environmental factors were favorable to getting 56K-range connections). If your ISP doesn't support V.90 but supports K56Flex, you have to explicitly tell the modem to operate in K56Flex mode to have any chance of achieving 56K-range connect speeds.
- Problems with phone company lines or switches or other equipment (coming in or out of your dialing location or in nearby switchboxes or junctions or at their switching office which serves your dialing location). Also, if the modem's signal has to pass through two or more analog-to-digital conversions at your phone company's central switching office and/or the phone lines in your dialing area are multiplexed, this will defeat achievability of 56K-range connect speeds.