Four of the five (well, FR in some new specs for things like inverse multiplexing) deal with the physical layer. Do remember, however, that the original OSI definitions of layering came from a telephony/WAN perspective, and did not consider LANs. Their physical layer specification is, indeed, a protocol. Most physical layer specifications do not actually define the characteristics of the medium, although they do make assumptions about the medium. But specifying the pulse shapes, clocking, etc., certainly is a protocol about how to use the medium. Data link protocols, among other things, deal with the interactions of multiple devices on a shared medium. Physical protocols deal with the interactions of single devices with a medium. For example, RS-232, RS-422/423, V.35, 10BaseT, 10Base5... Medium specifications deal with the medium itself. Media are less likely to be standardized by the same bodies that generate higher-layer protocol specifications. >From: "Ed Moss" <[EMAIL PROTECTED]> >Reply-To: "Ed Moss" <[EMAIL PROTECTED]> >To: [EMAIL PROTECTED] >Subject: Re: a ccna question-help >Date: Fri, 28 Jul 2000 14:15:49 -0500 > >It may be how you look at it... looking at "select the best answer" - I say >ATM, Token Ring and FDDI. These require single point-to-point connections. > >I believe Ethernet and Frame Relay (NBMA) are multiaccess mediums. > >The question it self may be a bit confusing as well since it says >"protocols". these are all physical mediums and not specifically >protocols. > >Ed > > > > I find a confused question on an exam guide which is: > > select the connect-oriented protocols: > > 1.ATM > > 2.TOKEN RING > > 3.FDDI > > 4.Ethernet > > 5.FrameRelay > > ___________________________________ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
