Merging with Block check character

Against :

FCS is a term that is used in Data link layer protocols in particular, while BCC is used in another world. - DéRahier 12:38, 1 October 2007 (UTC)[reply]

Strongly Against as per DéRahier. FCS appears at the end of Ethernet frames at layer 2, but BCC appears periodically within IBM bisync communications with a mainframe at layer 5. If the bisync com were contained in Ethernet frames across a LAN or MAN or WAN, then there would be a BCS at layer 5 within the payload of the Ethernet frame and then an FCS at layer 2 in the trailer of the Ethernet frame. The FCS in the Ethernet trailer is 4 bytes and uses the polynomial x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1. The BCC in the IBM terminal HDLC stream is 16 bits and uses the polynomial X^16+X^15+X^2+1. Ethernet frames are not an HDLC stream nor vice versa. I must admit that I am annoyed with people who do nontechnical "copy editing" such as merging articles that shouldn't be merged and deleting articles that shouldn't be deleted without doing the necessary homework. Simple Google searches on "Ethernet FCS polynomial" and "IBM BCC polynomial" pulled up this information quite easily in the first few search results. I am afraid that I see little commonality at all between FCS and BCC other than they are a bunch of ones and zeros. Perhaps we should merge all teledatacom and computer articles into one article called Ones and zeros. Please do some of the obvious Google searches to see if topics are synonymous *before* suggesting that their articles be merged. —optikos 11:31, 4 October 2007 (UTC)[reply]

I agree. I have found too much recent merging and simplification of wikipedia articles, which eliminates useful information. I gave up helping. I came here searching for relevance for fcs errors (when you find them) I know you tend to see them with a duplex mismatch, but forgot which side shows the fcs errors.--128.196.164.121 (talk) 19:58, 26 November 2007 (UTC)[reply]

For They're both the same thing with different names, and should be described (and understood) together. Protocols get encapsulated within others all the time; there's no limit on the number of checksums you can have in a single packet if you count all the different layers of encapsulation.

The complaint above seems somewhat ridiculous to me. Ethernet and HDLC checksums not just both bits, they're both fixed-length CRC trailers protecting variable-length data frames. (Even a simple longitudinal XOR is actually a CRC with a polynomial of x⁸+1 (8 bits) or x⁸+1 (7 bits).) The only difference is the polynomials used and the terminology used to describe them. This is not "nontechnical copy editing", it's good pedagogy recognizing multiple instances of the same basic principle and explaining them together. I expect harmonic oscillator to explain both the mechanical and electrical forms, and I expect one unified article to explain checksum trailers. 71.41.210.146 (talk) 13:35, 12 January 2008 (UTC)[reply]