router stats what do these things mean?

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Author: browolf PostPosted: Fri Dec 08, 2006 11:56 am    Post subject: router stats what do these things mean?
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trying to sort out some problems with my broadband; always wanting to see what I can find out myself. If would help if someone could explain what the following things in my router mean exactly:

near end indicator
far end indicator

Interleaved Path FEC Correction
Fast Path CRC Error
Interleaved Path CRC Error
Loss of Signal Defect
Fast Path HEC Error
Interleaved Path HEC Error

Author: minkata PostPosted: Tue Jan 09, 2007 8:18 am    Post subject: router jargon
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hi browolf ,
here are some info
> near end indicator: NEXT (Near End Cross Talk)
>far end indicator : FEXT (Far End Cross Talk) give an indication of signal degradation in physical circuits http://whatis.techtarget.com/definition/0,,sid9_gci1059969,00.html

> FEC Correction: (forward error correction) uses codes containing sufficient redundancy to prevent errors by detecting and correcting them at the receiving end without retransmission of the original message. The redundancy can vary from a small percentage of extra bits to complete redundancy ie: 100% so the error detecting bits more or less equal the number of data bits. FEC is commonly used in satellite transmission where data can easily be corrupted by distance , weather, solar flares etc
> CRC Error: (cyclical redundancy check )an error checking method www.ross.net/crc/crcpaper.html
(ethernet still add CRC to check paquets for errors but simply drops faulty ones , so TCP which uses ARQ (Automatic Repeat reQuest)as an error control will recognise any number of packets dropped by ethernet and retransmit them , effectively placing the responsibility between sender and receiver , thus freeing any computers along the way from ensuring a reliable delivery.)
>Loss of Signal Defect : www.ttc.or.jp/e/summary/inter-network/pdf/g775.pdf
> HEC Error: (Header Error Control) is part of the cell format used by ATM Asynchronous Transfer Mode http://ipoint.vlsi.uiuc.edu/abr/atmintro.html#ATM%20Cell%20Format
>Interleaved Packet switching: makes use of the fact that most communication of data consist of short burst of data which intervening spaces that usually last longer than bursts of data ; packet switching interleave bursts of data from many other users as to obtain maximum communication use. Of course it was necessary to mark each packets with a destination address and a sequence number for message reconstruction because the packets may use any available routes and arrive at the address in a jumbled sequence which is reordered at arrival.Two methods are used:> datagram and the more common:> method virtual circuit in which case the packet-switched-network establishes what appears to be one end-to-end circuit between sender and receiver. The consequences of this are that most common carriers will specify data rates such as CIR (Committed Information Rate)which is the guaranteed rate and the MAR ( Max Allowable Rate) which is the rate will attempt to provide over and above the CIR and will mark all theses packets as DE (Discard Eligible). This means that when a network becomes overloaded DE packets are discarded leaving the user with the CIR .
>Fast path: most embedded communications applications can be partitioned into fast-path and slow-path functions. Fast path operations are implemented in CPM (Communication Processor Module) and or QUICC (Quad Integrated Communications Controller)Engine microcode and aggressively optimized for maximum performance http://physics.usask.ca/~angie/ep414/labmanual/MotorolaDoc/MC68360UM/360UM-P2.pdf Arabella software , author of EFP (Expedited Fast Path) give some light on fast path functions and how the CPM can be made to handle only fast path operations www.analogzone.com/netp0808.htm
Source include readings : Business Data Communications and Networking by Jerry FitzGerald and Alan Dennis -eight edition.
I hope you will find this info helpful .
Minkata



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