We support V.90 at all sites
The rest of this page is general 56k dialup information.
ISDN dialup greatly improves your Internet access by improving the type of telephone service you use. It requires that you have ISDN digital telephone service from your telephone company.
You can use 56k without special phone service, but your Internet service provider needs digital phone service. Often the digital phone service the provider uses is ISDN phone service, and this is why there's some confusion about 56k dialup and ISDN.
A provider also can use a lower grade digital phone service to offer 56k dialup, with some sacrifice in connect rates. We use this option only where ISDN is not available.
A provider using ISDN for the digital phone service for 56k dialup can offer both 56k dialup and ISDN dialup with the same access number. This is another reason ISDN and 56k dialup are often confused.
56k can work over many normal phone lines, but it cannot work on some of them. See our page on why some calls can't connect at 56k.
The upstream direction is still limited to 33.6k. However, upstream speeds in the mid 40's have been demonstrated but not with any "56k" protocol now on the market.
V.90 is an amalgam of two 56k dialup technologies that preceded it, K56Flex and X2. These technologies do not work together, neither works with V.90), and they were at the center of a struggle for market dominance.
Also in the works is an all-digital standard V.91. This will allow users with digital phone lines, such as those at corporate installations with PBXs, to use "56k" dialup in both directions.