Networking

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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.

(warning) 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.

(информация) By default the PCI Ethernet adapters use first available PCI slot. If instead some particular slot is needed, refer to this section for details of specific placement of PCI peripherals on CHARON-AXP PCI bus.

(warning) Network booting is not currently supported.


Configuration steps

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

  1. Load network adapter (if required)

    Use the "load" command as shown below.

    Example:

    For DEC21040 adaptersFor Intel i8255x adapters
    load DE500BA/dec21x4x NIC
    load DE602/i8255x NIC

    (информация) By default each loaded virtual network adapter uses first available PCI slot. If instead some particular slot is neded, refer to this section for details of specific placement of PCI peripherals on CHARON-AXP PCI bus.

  2. 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"

               

  3. 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

Each virtual network controller has the following parameters that are specified with the "set" command:

interface

Parameterinterface
Type

Text String

Value

Name of the corresponding instance of the "packet_port" component

station_address

Parameterstation_address
Type

Text String

Value

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.

Format:

XX-XX-XX-XX-XX-XX

or

XX:XX:XX:XX:XX:XX

Example:

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

rx_fifo_size

Parameter

rx_fifo_size

TypeNumeric
Value

"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.

adapter_mode

Parameteradapter_mode
TypeText String
Value

Assigns the link speed and the duplex settings of the virtual network adapter (except for DE602/DE602AA - see below).

The values are:

ParameterDescription
"Auto"Auto-negotiate (default)
"10BaseT-HD"10Mbps half duplex
"10BaseT-FD"10Mbps full duplex
"100BaseT-HD"100Mbps half duplex
"100BaseT-FD"100Mbps full duplex

Example:

set EWA adapter_mode="100BaseT-HD"

Example

load packet_port/chnetwrk EWA0 interface = "connection:Charon"
set EWA interface = EWA0
set EWA station_address="0C:FE:35:AA:67:3B"

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DE602 and DE602AA network adapters link speed and duplex settings

Regardless of the "adapter_mode" setting in CHARON-AXP configuration file (see above), DE602 and DE602AA network adapters remains in "Auto-negotiation" mode, since the EIDRIVER of OpenVMS checks for EIx0_MODE environment variable when configuring the network card.

So mode propagation is implemented in CHARON-AXP via SRM console EIx0_MODE environment variable ("x" is A, B, C... depending on CHARON-AXP configuration), for example:

>>>help set

usage: set <variable-name> <value>
set <variable-name> ""

set eia0_mode { Twisted | Full | Fast | FastFD | Auto* }

>>>

(warning) The EIx0_MODE variable name is case insensitive, while its values are case sensitive! This is feature of OpenVMS EIDRIVER.

The values are:

ParameterDescription
"Auto"Auto-negotiate (default)
"Twisted"10Mbps half duplex
"Full"10Mbps full duplex
"Fast"100Mbps half duplex
"FastFD" 100Mbps full duplex

Example:

>>>set eia0_mode FastFD

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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 HP Alpha 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 NDIS

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

interface

Parameterinterface
Type

Text string

Value

This parameter identifies an Ethernet adapter of the host system dedicated to CHARON-AXP. The leading keyword "connection:" is mandatory.

Syntax:

set <name> interface="connection:<adapter>"

Example:

set NDIS interface="connection:Charon"

port_enable_mac_addr_change

Parameter

port_enable_mac_addr_change

TypeBoolean
Value

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

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

Example:

set NDIS port_enable_mac_addr_change=false

port_retry_on_tx

Parameter

port_retry_on_tx

TypeNumeric
Value

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 NDIS port_retry_on_tx=8

port_pending_rx_number

Parameter

port_pending_rx_number

TypeNumeric
Value

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 NDIS port_pending_rx_number=128

port_pending_tx_number

Parameter

port_pending_tx_number

TypeNumeric
Value

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 NDIS port_pending_tx_number=128

suspend_msg_on_mac_change

Parameter

suspend_msg_on_mac_change

TypeBoolean
Value

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 NDIS suspend_msg_on_mac_change=false

log

Parameter

log

TypeText string
Value

If this parameter is set to some valid file name or a directory where the log files for each individual session will be stored CHARON logs Recv and Xmit packets at the emulated port layer.

If an existing directory is specified, CHARON automatically enables creation of individual log files, one for each session using the same scheme as used for the generation of the rotating log files. If the "log" parameter is omitted, CHARON does not create log.

In certain situations enabling this parameter may help to detect loss of packets.

Example:

set NDIS log="ndis.log"
set NDIS log="C:\Charon\Logs"

legacy_mode

Parameterlegacy_mode
TypeBoolean
Value

If this parameter is set to "true" CHARON-AXP tries to use very first implementation of "packet_port" having certain restrictions such as inability to automatically change MAC address on given interface etc.

This setting may be needed if CHARON-AXP runs in VMware environment for example and you do not want to allow promiscuous mode.

In other situations please do not change its default value ("false").

Example:

set NDIS legacy_mode=true

Example

load DE500BA/dec21x4x EWA
load packet_port/chnetwrk EWA0 interface="connection:Charon"

set EWA interface=EWA0

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