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From: forster@cisco.com (Jim Forster)
Newsgroups: comp.dcom.sys.cisco
Subject: Re: Sun <-> cisco PPP interoperability
Message-ID: <31754@boulder.Colorado.EDU>
Date: 24 Jan 91 04:58:48 GMT
Sender: daemon@boulder.Colorado.EDU
Lines: 23

Vince,

We put the same bits out on the V.35 or RS-449 line no matter what the
speed.  We neither off nor accept options.  Given that it works at 56k but
not T-1, possibilities that come to mind (which you've probably tried but
which are worth repeating) are:

	- CSU/DSU configuration: 1.54 vs. 1.35 mb/sec, inverted/non-inverted
	  data, SCTE signal usage
	- V.35 cable length
	- twisted pair cable length & twists per foot
	- run through the various loop back modes
	- cisco sending packets too quickly together.  Unlikely if not
          impossible during LCP bringup, but can be ruled out by
	  slowing us down with the "transmitter delay" command.

I hope someone with more Digital Telecom expertise will correct me or 
add on.

Have fun and good luck!


  -- Jim