Networking

General description

CHARON-AXP supports emulation of the following network adapters:

DE435
DE450
DE500AA
DE500BA
DE602
DE602AA

Each of them is a PCI Ethernet adapter (based on the DEC21040 (DE435, DE450, DE500AA and DE500BA) and the Intel i8255x (DE602 and DE602AA) PCI Ethernet adapter chips) for the HP Alpha.

CHARON-AXP maps the virtual adapter to a dedicated Ethernet adapter in the Windows host system.

All the emulated controllers are loaded and configured in the same way.

The Ethernet adapter in the Windows host system must support dynamic changes of its MAC address (i.e. no reboot of the host system is required to change the MAC address), which is the case with nearly all modern Ethernet adapters.

Configuration steps

To configure CHARON-AXP networking, follow these 3 steps:

Load network adapter (if required)
Use the "load" command as shown below.

Example:
For DEC21040 adapters For Intel i8255x adapters
load DE500BA/dec21x4x NIC
load DE602/i8255x NIC
Load "packet_port"
Load "packet_port" to connect network adapter to the host hardware network card (or to a virtual network interface).

Example:
load packet_port/chnetwrk NDIS interface = "connection:Charon"
Connect the loaded "packet_port" to the loaded virtual network adapter
Connect the network adapter to the "packet_port" by setting the interface name.

Example:
set NIC interface = NDIS

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Configuration parameters

The built-in SGEC controller emulator ("EZA") has the following parameters that are specified with the "set" command:

Parameter

Type

Value

interface

Text String

Name of the corresponding instance of the "packet_port" component

station_address

Text String

The "station_address" provides the ability to configure the adapter’s permanent address. By default the adapter’s permanent address is read from the host system’s NIC.

Set the "station_address" when you need to configure a satellite (remotely booted) system that will run DECnet or when the migrated software uses the permanent address on the network adapter.

Format:

XX-XX-XX-XX-XX-XX

or

XX:XX:XX:XX:XX:XX

Example:

set eza station_address="AF:01:AC:78:1B:CC"

rx_fifo_size

Numeric

"rx_fifo_size" sets the receive FIFO size.

The value is specified in Kb and, by default, is pre-calculated from the connected port’s size of the receive queue.

Typically, you do not need to change the "rx_fifo_size" parameter. It is available for extended tuning and debugging purposes.

Example:

load packet_port/chnetwrk EZA0 interface = "connection:Charon"
set EZA interface = EZA0
set EZA station_address="0C:FE:35:AA:67:3B"

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Packet Port

The CHARON-specific "packet_port" interface establishes a connection between an Ethernet adapter in the Windows host system and a network adapter in the virtual VAX/PDP11 system.

For every virtual adapter instance loaded, one dedicated host Ethernet physical adapter is required.

To create instances of the "packet_port", use the “load” command in the configuration file as follows:

load packet_port/chnetwrk <instance-name>

Example:

load packet_port/chnetwrk pp_1

"packet_port" uses several configuration parameters to control its behavior.

Parameter

Type

Value

interface

Text string

This parameter identifies an Ethernet adapter of the host system dedicated to CHARON-AXP.

Syntax:

set <name> interface="<adapter>"

Example:

set pp_1 interface="eth0"

port_enable_mac_addr_change

Boolean

If "true" is specified (default value), CHARON sets the appropriate Ethernet address automatically.

If "false" is specified, set the Ethernet address manually.

Example:

set pp_1 port_enable_mac_addr_change=false

port_ignore_on_rx

Numeric

The "port_ignore_on_rx" parameter provides the ability to shutdown the port when a specified number of sequential "on receive" errors is exceeded.

Typically, errors "on receive" indicate serious (unrecoverable) errors.

By default, the value is set to the value of the "port_pending_rx_number" parameter. A value of ‘0’ means infinite.

Example:

set pp_1 port_ignore_on_rx=16

port_retry_on_tx

Numeric

The "port_retry_on_tx" parameter controls the number of times a port will attempt to transmit a packet before giving up.

By default, the value is 3.

Increasing this value may introduce problems in carrier loss logic, because not all NIC drivers support a carrier status query.

Typically, you do not need to increase the value.

Example:

set pp_1 port_retry_on_tx=8

port_pending_rx_number

Numeric

The "port_pending_rx_number" parameter sets the number of pending receive buffers.

The default value is 63. The maximum value allowed is 195.

You may want to increase the "port_pending_rx_number" when you have very busy networking and experience problems like losing connections not related to the carrier loss.

Typically, you do not need to change this parameter.

Example:

set pp_1 port_pending_rx_number=128

port_pending_rx_number

Numeric

The "port_pending_tx_number" parameter sets the number of buffers the port uses to transmit.

The default value is 62.

You may want to increase the "port_pending_tx_number" value if the log file indicates dropped TX packets due to TX queue overflow.

Typically, you do not need to change this parameter.

Example:

set pp_1 port_pending_rx_number=128

suspend_msg_on_mac_change

Boolean

To avoid confusion arising from non critical errors during a MAC address change, logging is by default suppressed (default value is "true").

To enable tracing during a MAC address change set this parameter to "false"

Example:

set pp_1 suspend_msg_on_mac_change=false

Example:

load DEQNA/DEQNA XQA

load packet_port/chnetwrk XQA0 interface="connection:Charon"

set XQA interface=XQA0

CHARON supports VLAN adapters. If for some reasons you are going to use them, proceed with their installation and configuration according to the network adapter's vendor's User's Guide and then use the resulting VLAN interface the same way as the regular network interface.

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Supported Ethernet Q-bus Adapters for DECnet OSI (DECnet Plus)

The only supported Q-bus device is the DELQA adapter model.

During DECnet OSI installation or DECnet OSI interface reconfiguration, DEQNA and DESQA models are not recognized as valid devices. (DECnet OSI SPD).

The integrated SGEC Ethernet "EZA" on a MicroVAX 3100 & VAX 4000-106/108 is supported by DECnet OSI.

The integrated ESA (AMD Lance 7990) device is not currently implemented in CHARON-VAX.

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Ethernet Q-bus Adapter and Cluster configuration rules

In a VMS Cluster using VMS version 5.5 and above, use only DELQA and DESQA Ethernet adapters that are supported (VMS Cluster SPD).

The default DEQNA device is not supported for SCS Cluster protocol and the emulated VAX will fail with a CLUEXIT Bugcheck.

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