mike@BRL.ARPA (Mike Muuss) (11/15/85)
1822L is the "logical addressing" feature, which is not implemented (or at least never used) on any of the popular IMP networks (ARPANET, MILNET, BRLNET, etc). To review the different IMP access methods: 1822 Local Host: fast TTL serial i/f, 5Meter limit, not often used any more in favor of... 1822 Distant Host: fast bipolar serial i/f, 2000 foot limit, rates up to 5 Mbps (burst). Currently the most common ARPANET host interface. 1822 Very Distant Host (VDH): no longer supported. Don't ask. 1822 HDLC Distant Host (HDH): HDLC-style serial line interface to an IMP, RS-232 up to 19.2Kbps, RS-422 up to 76Kbps. 1822 X.25 (Standard Mode): X.25 host-to-IMP access protocol, using ordinary X.25 link hardware. Sends traffic to IMP using X.25; no end-to-end X.25 significance. 1822 X.25 (Basic Mode): MILNET's "attract mode", allows IMPs to pretend to be a Public Data Net (PDN) offering X.25-only service. Intended to be used as a stepping stone to Standard Mode. No interoperability with TCP/IP portion of the network. Further discussion of these issues should be moved to the TCP-IP@SRI-NIC.ARPA list (net.tcp-ip ?) -Mike