Release Notes 93000221J
				   for
		      PORTSERVER II Operating System
				40001260H
			      Version 3.0.6
		       Product Manual P/N 90030500B
		    Command Reference Guide 92000246A
			       Mar 15, 1998


       Introduction
	   These release notes provide information on PortServer II
	   OS version 3.0.6.  Included are there following:
	   - Incompatibility between older versions of the
	     PortServer	II OS and this one, which can affect your
	     configuration.
	   - ROM limitations for those with Pre-Rev K Model
	     PortServer	IIs.
	   - Limitations for systems with fewer	than 2 Mb of
	     memory.
	   - Manual errata.
	   - Upgrading flash ROM.
	   - Changes to	the OS since it	went through beta testing.
	   - Bug fixes in this release.	 These include both bugs
	     reported in Problem Report	Numbers	as well	as some
	     that were not reported.

       Pre-3.0 Incompatibility Notice
	   This	version	(3.0) of the PortServer	II OS is
	   incompatible	with versions older than 3.0.  Certain
	   parts of the	non-volatile storage formats used to store
	   configuration information have been changed.
	   Consequently, if you	want to	use this version of the	OS
	   and preserve	your current configuration, you	must use
	   the cpconf command to save your configuration to a host
	   and then restore it once the	new version of the
	   PortServer II OS has	been installed.

       Pre-Rev K Model ROM Limitations
	   The addition	of Frame Relay to 3.0 and later	versions of
	   the OS causes the size of the boot image to exceed the
	   space available in the PortServer II	flash ROM for units
	   built prior to the Rev K models.  Consequently, you want
	   to use a 3.0	or later OS with these older units, you
	   must	do one of the following:
	   - Boot PortServer II	via TFTP over the ethernet port.
	   - Acquire a smaller version of the OS, which	does not
	     have Frame	Relay, this is available fro the Digi ftp
	     site.

       Limitations for Systems with 2 Mb of Memory
	   Testing has determined that the PortServer II's
	   previously standard 2 Mb of installed memory	is
	   inadequate in the following instances and is	likely to
	   require an expansion	to at least 4 Mb.

	   - Full 64 port configurations in which more than 50
	     asynchronous and/or TCP users are simultaneously using
	     PortServer	II.  This include users	accessing
	     PortServer	II via the ethernet connection or any type
	     of	connection using the serial ports.

	     Note: Exceeding this number of users is unlikely in
	     RealPort environments because each	RealPort connection
	     is	seen as	a single user.	This means that	while that
	     user may control more than	one port, if there is only
	     one host connected	to the PortServer II using
	     RealPort, it will use only	a little more memory than
	     someone making a telnet connection.  If more than one
	     host is using PortServer II as a RealPort server, each
	     host will have it's own TCP connection, and therefor
	     each is considered	a user.	 It is unlikely	that a site
	     will have enough RealPort connections to cause
	     problems.

	   - Sites with	heavy traffic on serial	ports.	Here the
	     problem is	simply throughput.  Degradation	of
	     performance may indicate that additional memory is
	     called for.

       Manual Errata
	   Page	47 of the PortServer II	User's Guide (90030500)
	   incorrectly states that a V.24 cable	is supplied with
	   the PortServer II.  This cable is not included.

	   Sync	parameters are automatically set when FrameRelay.
	   To ensure proper operation of the Synchronous Port the
	   port	must be	set to "dev=term" OR "dev=prn".	 It is
	   further recommended that all	setting	contained in "set
	   flow" be set	to "off".

       Upgrading Flash ROM
	   Should it be	necessary to update the	PortServer II OS
	   contained in	Flash ROM on your PortServer II, the
	   recommended procedure is:
	   1.  Obtain the new version of the software from Digi	and
	       place it	on your	TFTP server.
	   2.  Save your current configuration using cpconf.  This
	       should not be necessary,	but it is advisable to
	       maintain	a backup of your current configuration when
	       re-writing a sizable portion of flash.
	   3.  Boot your portserver with the new operating system
	       via TFTP, by using set config boothost=hostip
	       bootfile=filename tftpboot=yes, and then	rebooting
	       your portserver.	 See page 45 of	the User's Guide
	       and Reference Manual for	more details.  This step
	       ensures that you	have a good copy of the	new version
	       of the software,	and also that you can still boot
	       your PortServer II in the unlikely event	that your
	       flash image gets	corrupted in the process of writing
	       it.
	   4.  After booting your PortServer via TFTP, load the	new
	       version of the software into the	flash ROM by using
	       the command boot	load=host:filename.  If	all goes
	       well, the PortServer will reply "The image now in
	       flash memory appears valid."
	   5.  Now you can return your PortServer II to	booting
	       from its	flash ROM image	by entering the	command	set
	       config tftpboot=no.

       Bug Fixes
	   The bug fixes addressed by this release include:
	   1.  PR #190.00000 - The UARTs used by the 16	base ports
	       ( 1 - 16	) could	apparently be put in a state where
	       it had two interrupts pending when only one had been
	       posted.	The result of this was that all	four ports
	       on that quad would be "hung" waiting for	the non-
	       existant	interrupt to be	cleared.  The OS will now
	       clear the interrupt twice if this is the	case.
	   2.  PR #225.00000 - An unsuccessful rsh or rlogin to	the
	       PortServer could	cause a	reset when the connection
	       was terminated.
	   3.  PR #178.00000 - a problem with menuing found while
	       looking at a change request.  Arbitrary commands	may
	       now be run from any menu.