Fastpath

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Fastpath (also FastPath ) is a feature for reducing the latency of ADSL connections. The advantages are better response times for online games or terminal connections (e.g. SSH ), lower speech delay and better echo suppression for Internet telephony, and slightly smoother web usage. In rare cases this can affect the effective transfer rate.

technology

Fastpath is implemented by switching off interleaving , an aid for error correction, on the route between the DSL modem and the transfer point at the telephone network operator ( DSLAM or MSAN ). With interleaving, the data blocks are transmitted in an interleaved manner in order to be able to better correct certain data errors, so-called burst errors , which arise from brief electrical disturbances on the telephone line. Due to this interleaving, it is necessary to wait until a data block is completely available before its transmission can begin. As a result, the return time of the data packets (so-called ping time ) is relatively high with an average of 60 milliseconds . With the FastPath option, the data packets are transmitted without interleaving and the latency drops to around 15 to 25 milliseconds, depending on the location of both network devices.

Transmission errors that may occur more frequently can be detected and corrected with TCP- based protocols (by retransmitting the affected packets); with connectionless protocols (e.g. using UDP ), incorrect packets are inevitably lost. Switching off interleaving can become problematic if the DSL connection, depending on the quality and length of the line, is already at the limit of its performance (see also signal-to-noise ratio ). This is checked by the telephone network operator before FastPath is activated .

Some DSL providers allow Fastpath to be paid a monthly fee, although this involves switching off an existing technology.

Others

Since 2009, the Deutsche Telekom - unlike other providers - no longer advertises Fastpath to private customers. For business customers, T-Systems offers the “Low Delay” option as a quality of service to reduce the signal delay .

Web links

Individual evidence

  1. ↑ Ralf Trautmann: Telekom: Fastpath still available (updated) . ( teltarif.de [accessed on February 13, 2018]).
  2. ↑ Ralf Trautmann: Telekom: Fastpath still available (updated) . ( teltarif.de [accessed on February 13, 2018]).
  3. ↑ Order Fastpath - that's how it works. Accessed February 13, 2018 .