Bytes are not part of the OSI model until at least the presentation layer (I can't remember whether there is an ASN1 byte datatype). Comms engineers talk about octets but note that by the time we get down to layer 2 we start to encounter techniques such as bit-stuffing, so a frame may not even have a multiple of eight bits in it. So from this we must assume that there is no conversion from bits to bytes or vice-versa. rgds Marc
Pierre-Alex Guanel wrote: > > This is clear. Thank you! > > Pierre-Alex > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of > Priscilla Oppenheimer > Sent: Tuesday, February 26, 2002 8:27 PM > To: [EMAIL PROTECTED] > Subject: Re: Bit / bytes [7:36562] > > Layer 1 just understands bits. Hardware, in general, understands voltage > and no voltage (one or zero). I guess it could understand high voltage and > low voltage. In fact, there's even ternary systems that understand high, > kinda high, and low. > > Back in the early days, software engineers got kind of sick of having to > deal with long streams of numbers and decided to aggregate them. An 8-bit > byte worked out for many systems. (There used to be systems that used a > 12-bit byte). > > So anything that is implemented in software (or software that has become > firmware) uses bytes or perhaps nibbles or words. Most NICs that handle > data-link-layer processes have some software (driver) or firmware (chip > set). Thus, I would say that they deal with bytes or nibbles or words or > floating integers or arrays or link lists or symbol tables or at least > something of a higher order than voltage being present or not. > > Priscilla > > At 07:12 PM 2/26/02, you wrote: > >Is conversion of bits into bytes and vice versa a function of Layer 1 or > >Layer 2? > > > >I have seen contradictory info. > > > >(I would say it is a layer 2 function because Layer 1 is only physical > >matters like voltage etc... but some one may have a logic to prove me > wrong) > > > > > >thanks, > > > >Pierre-Alex > ________________________ > > Priscilla Oppenheimer > http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=36750&t=36562 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
