Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cs.utexas.edu!sm.unisys.com!csun!lkw From: lkw@csun.edu (Larry Wake) Newsgroups: comp.dcom.lans Subject: cisco-to-cisco over 1.5M serial? Keywords: T1, cisco, CSU/DSU, is this trip really necessary? Message-ID: <1751@csun.edu> Date: 7 Dec 88 20:48:47 GMT Reply-To: lkw@csun.edu (Larry Wake) Organization: California State University, Northridge Lines: 29 We have pretty much settled on using a high-speed serial connection to bridge Ethernet segments located in two buildings on campus. Our proposed method is to use a cisco gateway server on each end, with what they call their "T1" interface (for reasons that may become clearer, I would like to avoid the term T1, though). The cable between the two buildings is T1-quality twisted pair (22 gauge dual D-screen), owned by the university, not the phone company; the run is about 2800'. Each cisco board has a V.35 connector, and they will talk HDLC. After talking with many, many vendors, we are still confused as to what we need to drive the serial line. Some (including cisco) say we need a CSU/DSU, others say only the DSU portion is necessary, and still others say only the CSU. Prices range from $1500 to $5000 a side. So, we still need to know what the technological difference between the different types of equipment is to justify the wide price range. In a nutshell, our main concern is: what is the most cost effective way to get a high speed (T1 or T1-C rate) connect between the two cisco boxes? If anyone has any direct experience and/or product recommendations, we would love to hear from them. More general questions include: what is a CSU? What is a DSU? Which of these is required only for telco connects, and which can be eliminated in a private setup such as ours? Thanks in advance, -- Larry Wake lkw@csun.edu CSUN Computer Center uucp: {hplabs,rdlvax}!csun!lkw Mail Drop CCAD BITnet: LKW@CALSTATE Northridge, CA 91330