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HEC and RS errors, what are they?

jim306
Grafter
Posts: 75
Registered: 31-10-2007

HEC and RS errors, what are they?

My router reports a lot of rs errors and fewer HEC errors, what do these mean and how, if at all, do they affect broadband performance?
2 REPLIES
pcoventry76
Grafter
Posts: 950
Registered: 27-08-2007

Re: HEC and RS errors, what are they?

Evening Jim,
HEC (Full Name Header Error Checksum) is to do with cells that are sent from BT's ATM network
here's a good bit of info from Cisco
http://www.cisco.com/en/US/products/hw/modules/ps3909/products_tech_note09186a0080094160.shtml
and here's a god bit about the ATM network - which is basically what carries the IP Stream around and is also refered to as a MSiP ( Multi Service Intranet Platform)
http://www.kitz.co.uk/adsl/equip2.htm#clouATM stands for Asynchronous Transfer Mode and this carries packets and cells. which when corrupt goes right back to HEC's
i'll admit i'm not that hot on FS errors, but i'll do some surfing around it tommorow
To understand a better idea of how the ADSL network is put together - TBB do a very good diagram
http://www.thinkbroadband.com/guide/howitworks/
You may already know this - but it's useful for people reading this thread who don't and are curious.

decomplexity
Rising Star
Posts: 493
Thanks: 26
Registered: 30-07-2007

Re: HEC and RS errors, what are they?

RS is Reed-Solomon encoding. In ADSL (and on CDs where the variant used is called CIRC) it is used as a form of parity code which can detect and correct bit errors. 
What is transmitted is not, however, a simple parity check sequence but the definition of a curve (literally the coefficients of a polynomial) which has been 'fitted' to the original data. 
Zen from May 17. PN Business account from 2004 - 2017