Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!nrl-cmf!cmcl2!rutgers!aramis.rutgers.edu!athos.rutgers.edu!hedrick From: hedrick@athos.rutgers.edu (Charles Hedrick) Newsgroups: comp.dcom.lans Subject: Re: Ethernet bridges and T1-izers Message-ID: Date: 27 Jul 88 00:57:15 GMT References: <9392@dartvax.Dartmouth.EDU> <24058@bu-cs.BU.EDU> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 15 Many T1-izers have options to select how much encoding is needed. Generally the specs tell you exactly what clock rate they present for each combination of options. E.g. there are options to say whether your telco well let you get away with bipolar violations (one specific kind of bipolar violation can be used to provides ones density more efficiently), and whether your signal has any known properties that will allow more bit-efficent processing (e.g. ours will do a better job if the signal is known to be HDLC). I think in some you can specify whether it has to worry about ones density, whether the signal already has T1 framing, etc. Typically you can get from something like 1.528Mbps to 1.544Mbps depending upon the kind of coding the box can do and what options you set. I haven't seen any that do compression. We're talking about slightly jazzed-up CSU's here (the official product name is normally "clear-channel CSU"). I think compression (particularly at this data rate) takes a bit more processing power than they have.