Path: utzoo!attcan!uunet!ncrlnk!emdeng!mmeier From: mmeier@emdeng.Dayton.NCR.COM (Marlin.Meier) Newsgroups: comp.protocols.ibm Subject: Token-ring FCS question Keywords: Token-ring, token ring Message-ID: <549@emdeng.Dayton.NCR.COM> Date: 22 Sep 88 12:58:04 GMT Organization: E&M Dayton, NCR Corporation, Dayton, Ohio Lines: 24 Could someone please explain what this means: The frame check sequence is generated using the following standard generator polynomial: G(X) = 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 + X^0. The frame check sequence is one's complement of the sum (modulo 2) of the following: 1. The remainder of X**k(X^31 + X^30 + ... + X^2 + X + 1) divided (modulo 2) by G(X), where k is the number of bits in the frame control field, destination and source addresses, optional routing information field, and information field. 2. The remainder after multiplication by X^32 and then division (modulo 2) by G(X) of the content (treated as a polynomial) of the frame control field, destination and source addresses, optional routing information field, and information field. Any explaination especially with an example would be greatly appreciated. Thanks in advance. Marlin Meier