Uncapping, in the context of
cable modem
A cable modem is a type of network bridge that provides bi-directional data communication via radio frequency channels on a hybrid fibre-coaxial (HFC), radio frequency over glass (RFoG) and coaxial cable infrastructure. Cable modems are primaril ...
s, refers to a number of activities performed to alter an
Internet service provider
An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise private ...
's
modem
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulati ...
settings. It is sometimes done for the sake of
bandwidth
Bandwidth commonly refers to:
* Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range
* Bandwidth (computing), the rate of data transfer, bit rate or thr ...
(i.e. by buying a 512kbit/s access modem and then altering it to 10Mbit/s), pluggable interfaces (as by using more than one public ID), or any configurable options a
DOCSIS
Data Over Cable Service Interface Specification (DOCSIS) is an international telecommunications standard that permits the addition of high-bandwidth data transfer to an existing cable television (CATV) system. It is used by many cable televisio ...
modem can offer. However, uncapping may be considered an illegal activity, such as
theft of service.
Methods
There are several methods used to uncap a cable modem, by hardware, software, tricks, alterations, and modifications.
One of the most popular modifications is used on
Motorola
Motorola, Inc. () was an American Multinational corporation, multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent p ...
modems (such as the SB3100, SB4100, and SB4200 models); by
spoofing the Internet service provider's
TFTP
Trivial File Transfer Protocol (TFTP) is a simple lockstep File Transfer Protocol which allows a client to get a file from or put a file onto a remote host. One of its primary uses is in the early stages of nodes booting from a local area netwo ...
server, the modem is made to accept a different
configuration file
In computing, configuration files (commonly known simply as config files) are computer file, files used to configure the Parameter (computer programming), parameters and Initialization (programming), initial settings for some computer programs. T ...
than the one provided by the TFTP server. This configuration file tells the modem the download and upload caps it should enforce. An example of spoofing would be to edit the configuration file, which requires a DOCSIS editor, or replacing the configuration file with one obtained from a faster modem (e.g. through a
Gnutella
Gnutella is a peer-to-peer network protocol. Founded in 2000, it was the first decentralized peer-to-peer network of its kind, leading to other, later networks adopting the model.
In June 2005, Gnutella's population was 1.81 million computer ...
network).
An alternate method employs DHCPforce. By flooding a modem with faked
DHCP
The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) networks for automatically assigning IP addresses and other communication parameters to devices connected to the network using a cli ...
packets (which contain configuration filename, TFTP, IP, etc.), one can convince the modem to accept any desired configuration file, even one from one's own server (provided the server is routed, of course).
Another more advanced method is to attach a
TTL
TTL may refer to:
Photography
* Through-the-lens metering, a camera feature
* Zenit TTL, an SLR film camera named for its TTL metering capability
Technology
* Time to live, a computer data lifespan-limiting mechanism
* Transistor–transistor lo ...
to the modem's
RS-232
In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such a ...
adapter, and get access to the modem's console directly to make it download new firmware, which can then be configured via a simple web interface. Examples include SIGMA, a
firmware
In computing, firmware is a specific class of computer software that provides the low-level control for a device's specific hardware. Firmware, such as the BIOS of a personal computer, may contain basic functions of a device, and may provide h ...
add-on that expands the current features of an underlying firmware, and others.
See also
*
Bandwidth cap
A data cap, often erroneously referred to as a bandwidth cap, is an artificial restriction imposed on the transfer of data over a network. In particular, it refers to policies imposed by an internet service provider in order to limit customers' u ...
References
{{reflist
External links
Fibercoax Group
TCNiSO Embedded Development Assembly Experts
Broadband
Internet terminology