Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!thumper!ulysses!andante!mit-eddie!bbn!uwmcsd1!ig!agate!ucbvax!PANDA.PANDA.COM!MRC From: MRC@PANDA.PANDA.COM.UUCP Newsgroups: comp.protocols.tcp-ip Subject: Re: Linking LAN's via Public X.25 Message-ID: <12403803889.8.MRC@PANDA.PANDA.COM> Date: 4 Jun 88 18:09:46 GMT References: <12403549643.58.LYNCH@A.ISI.EDU> Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 27 Dan - I'm responsible for one of the TCP/IP implementations used on a 9600 baud link in Canada. The system is a DEC-2065 running a TOPS-20 with a heavily modified TCP. It has two IP interfaces; a NIA20 to the local Ethernet and an AN20 to a C/30 PSN using 1822. This TCP lacks RFNM counting which is a serious deficiency, but in the case of this link it doesn't really matter all that much since (at least the last I read) there is only one place for the 1822-grams to go to. If you're RFNM blocked to the friendly not-so-local gateway, you can't do anything anyway. What makes the burden worse, this machine is the only path between the local Ethernet (which talks TCP/IP and DECnet) and the rest of the world. It has a rudimentary EGP-speaker that babbles updates to Friend Gateway. I've seen no indication of a bottleneck at the DEC-20. Instead, it seems to be more that the DEC-20 (and the Symbolics Lisp machines behind it on the Ethernet) are communicating almost exclusively with the Internet in the US, across two gateways over a long long wire. There isn't all that much traffic to begin with, so any latency in a connection can easily stop the line...because there is no other traffic! -- Mark -- -------