DIGITAL ATMswitch 900 Firmware Release Notes
Firmware Version 2.0
April 1998



These release notes provide information about the DIGITAL ATMswitch 900 Version 2.0 firmware.  
This release supports both the ATMswitch 900F and the ATMswitch 900T modules.   

NOTE
ATMswitch 900 Version 2.0 firmware includes a new command line interpreter (CLI).  See the
ATMswitch 900 Management (EK-DAHSF-MG. B01) manual for descriptions of the commands and options
 of the CLI.

Important: Read This First

You should check that your ATMswitch 900 firmware release is the latest version by checking the
latest firmware release notes that are available online from the DIGITAL FTP site and the Network
Product Business Web Site.  If it is not the latest version, you should upgrade it immediately as 
described in the Installation and Configuration book.  To determine the current firmware versions,
use the versions command at the ATMswitch-> console prompt.  

Introduction

This document contains important notes for the ATMswitch 900 module, including information about: 
 
	Firmware locations and upgrades 
	Configuration guidelines 
	Support for modular PHY loop timing 
	Known problems 
	Unsupported features 
	Online information access 

How to Get a Copy of ATMswitch 900 Firmware
The latest firmware kit is located in a release area at the DIGITAL FTP site (ftp.digital.com). 
Copy the image to your system using these commands:  

# ftp ftp.digital.com
username: anonymous 
password: (your Internet address)
ftp> cd /pub/DEC/GIGAswitchATM 
ftp> bin 
ftp> get file-name file-name  
ftp> bye

where file-name is the name of any file that you are copying.  
For example, if you are using a UNIX system, you might copy the A900Rn_n.tar file where  n_n 
indicates the version number (for example, V2.0 would be 2_0).  To unpack the new image, use the
following UNIX command:
 
# tar -xvf A900Rn_n.tar 

This command creates a subdirectory named A900Vn_n within your current working directory.  
The following files are unpacked into the A900Vn_n subdirectory:  

A900Rnn.CTL 	Sample control file 
A900Rnn.BIN 	Application image 
A900Rnn.ROM 	Kernel image 

If you are using another operating system, you might want to copy the files listed in the 
above table.  

Upgrading the Firmware

For more detailed instructions about the firmware upgrade procedure, see the Upgrading the 
Firmware section of the Installation and Configuration book.  

Configuration Guidelines

Slot Restrictions for the DIGITAL MultiSwitch 900

If you are using a DIGITAL MultiSwitch 900 (formerly DEChub 900 MultiSwitch), the ATMswitch
900T module does not have any slot restrictions.  

However, the ATMswitch 900F module can only be configured in slots 7 or 8 of the 
DIGITAL MultiSwitch 900.   If the module is not in an appropriate slot, you will see the 
following LED indications:  

	Module OK LED is off.   
	PHY3 and PHY6 LEDs are amber. 
	FRU4 and FRU5 LEDs are amber. 

Port Restrictions for the DIGITAL MultiSwitch 900

If you are directing ports 5 through 8 of the ATMswitch 900 module to the backplane of 
a DIGITAL MultiSwitch 900 for interconnection to other ATMswitch 900 modules, the ports 
must be connected to the same numbered port on the connected modules.  For example, port 5 
on one ATMswitch 900 module must be connected to port 5 on an interconnected 
ATMswitch 900 module.  

LAN Emulation

If you are using LAN Emulation (LANE), you should be aware of the following guidelines: 
 
	To allow access from other switches to the LECS, create a static route between 
	the switch that has the LECS enabled and the well-known LECS address.  The static 
	route's forwarding slot should be set to 1 and the forwarding port should be set to 0.  
	This route must be exported.  
	When using LANE over an E1 link, the BUS rate limit must be set to less than 500 kb/s. 
	12 emulated LANs (ELANs) is the maximum number supported.  The BUS rate for each ELAN 
	should not exceed 500 kb/s.  
	80 LANE clients is the maximum number supported.	

Constant Bit Rate Circuits

When configuring constant bit rate (CBR) circuits for E1, E3, T1, or T3 links, set the 
CBR link rate to a value that is less than 70% of the total allowable link rate.  

The maximum CBR bandwidth is 400 Mb/s.  

Maximum Sustained Throughput

800 Mb/s is the maximum sustained throughput supported.  Traffic might be discarded when 
this value is exceeded.  

Virtual Circuit Range Support

The ATMswitch 900 module supports 2000 switched virtual circuits and 2000 permanent virtual
circuits total.  These virtual circuits can be distributed across all ports in any fashion.  
If you are using ports 7 or 8, these ports only support up to 1700 virtual circuit 
identifiers (VCIs).   

Maximum VCI Ranges for a Link
If the remote node has a limited virtual circuit identifier (VCI) range and the VCI ranges
are not exchanged with the switch using ILMI link-up procedures, you might have to configure
the maximum VCI range with the link command.  The maximum VCI value should be the maximum VCI
of the remote node.  Refer to the ATMswitch 900 Management manual for more information about
the link command.

Setting the Module Startup Mode

To set the module startup mode, use the setStartupMode('mode') command.  The value for mode 
can be one of the following:  

	0 (zero) indicates normal startup mode with self-test.  
	F indicates normal startup mode without self-test. 
	L indicates image load.  If you use this startup mode, you must reset the startup 
	mode to 0 or F and reboot the switch.  Do not use this mode with the 
	DIGITAL MultiSwitch 900.

Slot Designations When Using ATM Commands or MIBs

When using ATM commands or MIBs, the slot value is always 1 and does not indicate the 
slot in the DIGITAL MultiSwitch 900 into which the module is plugged.  

Support for Modular PHY Loop Timing
The ATMswitch 900 firmware supports the selection of the transmit timebase.  SNMP already 
supports read-write access of the transmit timebase for DS3, DS1, E3, and E1.  The 
menu interface also supports read-write access to the transmit timebase for all interfaces
with menu option 3.8 (Modify Transmit Clock Generation Source). 
  
Supported modPHY Types

The following modular PHY (modPHY) cards are supported for this release:  

modPHY Type 				Part Number 
E1 (2 Mb/s) short reach TP 		DAGE1-AA 
E3 (34 Mb/s) coaxial 			DAGGE-AA
DS1/T1 (1.54 Mb/s)  short reach TP	DAGT1-AA 
DS3/T3 (44 Mb/s) coaxial		DAGGT-AA
STS-3c (155 Mb/s) UTP/ScTP		DAGGU-AA
OC-3 (155 Mb/s) MMF			DAGGM-AA 
OC-3 (155 Mb/s) SMF 			DAGGS-AA
 
Transmit Timebase Selection and Nonvolatile Parameter Storage
Transmit timing sources are established for each link.  Each physical link can be 
configured to derive its transmit timing from either a local oscillator or the recovered 
receive clock.  Local timing specifies that the transmit timing is derived from the local 
oscillator.  Loop timing specifies that the transmit timing is derived from the recovered 
receive clock.  

System Behavior at Switch Reboot and Across modPHY Hotswap

When the switch is rebooted, the nonvolatile records for each populated link are examined.  
If a record is found for the PHY type detected, the stored setting is used.  If a record 
is not found, local timing is used.  This implies that if a PHY type is changed while the 
switch is powered down, switch initialization will not necessarily yield the default setting.  
The same sequence of actions occurs if a link is unpopulated at switch powerup, but is populated 
later.  

When modPHY hotswap yields a PHY type change, the new link is initialized with the default 
setting (local timing).  When modPHY hotswap does not result in a PHY type change, the link is 
reinitialized with its last known setting (if it is not overridden by a condition described in 
the next section).  Note that hotswap does not trigger a nonvolatile record update.  So, a subsequent 
switch reboot might, by virtue of a previously stored record for that link and type, change the 
timing setting.  

Effect of Port Conditions on the Transmit Timebase Setting
Two conditions, loss of signal and loss of frame, will force a loop-timed link to revert to 
local timing.  Subsequent clearing of the condition will force such a port back to loop timing.  
Neither of these forced transitions will cause a nonvolatile record update.  

Known Problems

Documentation Errata

On page 5-2 of the ATMswitch 900 Management hardcopy manual, under Displaying the Current 
Date and Time, the example is invalid. The example should read:

ATMswitch-> date
Time since last initialization: 118 hrs, 17 mins, 50 secs

UNI Version and IISP Links

When there is an IISP link between two DIGITAL ATM switches, the UNI version is specified 
as UNI 3.1 by default.  Do not specify any UNI version other than UNI 3.1.  

Telnet Session on Existing Connection

Invoking a Telnet session to a switch that is already used by a serial line connection 
causes the initial session to be locked out until the Telnet session is terminated.  
Unsupported Features in This Release

The following features are not supported in this release:  

	IP switching 
	Rate-based flow control 
	EFCI 
	SLIP/OBM port 

Note that running CLIP client and Redundant Lane services may result in intermittent problems.

Accessing Online Information

Further information on this network product or topic is available on the Network Product 
Business Web Site.  The Web Site maintains a common, rich set of up-to-date information 
about DIGITAL networking products, technologies, and programs.  The Web Site can be reached 
at geographic locations via the following URLs:

Americas Network Product Business Home Page
http://www.networks.digital.com/ 

Europe Network Product Business Home Page
http://www.networks.europe.digital.com/ 

Australia Network Product Business Home Page
http://www.networks.digital.com.au

Digital Equipment Corporation Home Page
http://www.digital.com/ 

To get firmware and MIB information, choose the "Technical Information" link, and from 
there choose the "Technical Information (Drivers, Manuals, Tech Tips, etc.)" link.















 Digital Equipment Corporation 1998. All rights reserved. Printed in U.S.A.
DEC, DIGITAL, and the DIGITAL logo are trademarks of Digital Equipment Corporation.
