Identifier The same value as that sent by the
LEX_RCMD_REQUEST packet
Length The same value as that sent by the
LEX_RCMD_REQUEST packet
Option-Type 0x02 (Filter MAC Address)
Option-Flags None
Option-Length The same value as that sent by the
LEX_RCMD_REQUEST packet
Option-Data The filter entries sent in the
LEX_RCMD_REQUEST packet
5.0 Set Priority
The host router sends a LEX_RCMD_ REQUEST with an Option-Type of 0x03
to the LAN extension interface unit to establish the sending priority
of different protocol type packets from the LAN extension interface
unit to host router. There are four levels of priority:
* High
* Medium
* Normal
* Low
Packets are classified according to protocol type and then are queued
to one of four output queues on the LAN extension interface unit that
correspond to the above priority levels. When the LAN extension
interface unit is ready to transmit a packet, it scans the priority
queues in order, from the highest to lowest, to find the highest
priority packet.
5.1 LEX RCMD_REQUEST - Set Priority
To establish priority queues for each protocol type, the host router
sends a Set Priority LEX_RCMD_REQUEST packet. Figure 8 shows a frame
format summary of such a LEX_RCMD_REQUEST packet. The host router
transmits the fields from left to right.
Figure 8 LEX_RCMD_REQUEST Packet Frame Format - Set Priority
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
LAN Extension Interface Remote Command Options
<--------------------------------
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option-Type | Option-Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1)
---------------------------------------------->
6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Option-Length | Option-Data |
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
(2)
Where the Option-Data field contains the following fields:
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol Type (16 bits) | Protocol Value (16 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Summary Field Descriptions
For a complete descriptions of the fields in the PPP Header, the LAN
Extension Interface Protocol Header, and the LAN Extension Interface
Remote Command Options, refer to the "Remote Command Options" section
earlier in this document. The following table provides a summary of
these fields when sending a LEX_RCMD_REQUEST packet that sets
priority queuing.
Table 6 Field Values for LEX_RCMD_REQUEST Packet - Set Priority
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code 0x40 (LEX_RCMD_REQUEST packet)
Identifier Valid values: 0x01-0xFF
Length Minimum length = 12 octets
Maximum length = 1028 octets
Option-Type 0x03 (Set Priority)
Option-Flags None
Option-Length Minimum length = 4 octets
Maximum length = 1020 octets
Option-Data Protocol Type and Priority Value. See the
following "Option-Data Field Description"
section for details.
Option-Data Field Descriptions
The following Option-Data fields set the priority queuing of
different protocol type packets.
* Protocol Type
The Protocol Type field contains a 16-bit number that is any Ethernet
type code. See the most recent "Assigned Numbers" RFCfor the correct
Ethernet type code.
* Priority Value
The Priority Value field specifies the priority queue for the
protocol type specified in the Protocol Type field. Valid values are
as follows:
- 0 - High priority queue
- 1 - Medium priority queue
- 2 - Normal priority queue
- 3 - Low priority queue
Sending a LEX_RCMD_REQUEST packet with an Option-Length of four (no
priority entries) disables priority queuing. When disabled, the LAN
extension interface unit transfers all packets at a normal (2)
priority level. When a new priority is specified, it overwrites the
previous setting.
5.2 Response Packets - Set Priority
The following packets are valid responses to the Set Priority
LEX_RCMD_REQUEST packet.
* LEX_RCMD_ACK - Set Priority
See the "Conditions for Sending PPP-LEX Packets" section earlier in
this document for more information on this packet type.
* LEX_RCMD_NAK - Set Priority
The LAN extension interface unit sends a LEX_RCMD_NAK packet in
response to the Set Priority LEX_RCMD_REQUEST packet when the request
contains an incorrect number of bytes in the message, when necessary
resources are not available, or when the specified priority is
invalid.
* LEX_RCMD-REJ - Set Priority
See the "Conditions for Sending PPP-LEX Packets" section earlier in
this document for more information on this packet type. Table 7
summarizes the field values of Set Priority LEX_RCMD_ACK,
LEX_RCMD_NAK, and LEX_RCMD_REJ packets.
Table 7 Field Values for Response Packets - Set Priority
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code Valid values:
* 0x41 (LEX_RCMD_ACK packet)
* 0x42 (LEX_RCMD_NAK packet)
* 0x43 (LEX_RCMD_REJ packet)
Identifier A randomly generated value that aids in
matching requests with replies
Length Minimum length = 12 octets
Maximum length = 1028 octets
Option-Type 0x03 (Set Priority)
Option-Flags None
Option-Length Minimum length = 4 octets
Maximum length = 1020 octets
Option-Data Protocol Type and Priority Value sent
in the LEX_RCMD_REQUEST packet
6.0 Disable LAN Extension Ethernet Interface
The host router sends a LEX_RCMD_ REQUEST with an Option-Type of 0x04
to the LAN extension interface unit to disable the LAN extension
Ethernet interface. This remote command option stops data traffic
from the LAN extension interface unit to the host router for
troubleshooting or for reconfiguring the LAN extension interface
unit. This remote command option only affects data traffic. PPP-LEX
control packets can still be transferred over the serial link.
6.1 LEX RCMD_REQUEST - Disable LAN Extension Ethernet Interface
Figure 9 shows a frame format summary of a LEX_RCMD_REQUEST packet
for the Disable LAN Extension Ethernet Interface remote command
option. The host router transmits the fields from left to right.
Figure 9 LEX_RCMD_REQUEST Packet Frame Format -
Disable LAN Extension Ethernet Interface
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
LAN Extension Interface Remote Command Options
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option-Type | Option-Flags | Option-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
Summary Field Descriptions
For complete descriptions of the fields in the PPP Header, the LAN
Extension Interface Protocol Header, and the LAN Extension Interface
Remote Command Option, refer to the "Remote Command Options" section
earlier in this document. The following table provides a summary of
these fields when sending a LEX_RCMD_REQUEST packet that disables the
LAN extension interface unit.
Table 8 Field Values for LEX_RCMD_REQUEST Packet -
Disable LAN Extension Ethernet Interface
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code 0x40 (LEX_RCMD_REQUEST packet)
Identifier Valid values: 0x01-0xFF
Length 12 octets
Option-Type 0x04 (Disable LAN Extension Ethernet
Interface)
Option-Flags None
Option-Length 4 octets
Option-Data None
6.2 Response Packets - Disable LAN Extension Ethernet Interface
LEX_RCMD_ACK, LEX_RCMD_NAK, and LEX_RCMD-REJ packets are valid
responses to the Disable LAN Extension Ethernet Interface
LEX_RCMD_REQUEST packet. Refer to the "Conditions for Sending PPP-LEX
Packets" section earlier in this document for more information on
when the LAN extension interface unit sends each of these response
packets. Note that the LAN extension interface unit sends the
LEX_RCMD_ACK packet after shutting down the interface.
Table 9 summarizes the field values of Disable LAN Extension Ethernet
Interface LEX_RCMD_ACK, LEX_RCMD_NAK, and LEX_RCMD_REJ packets.
Table 9 Field Values for Response Packets -
Disable LAN Extension Ethernet Interface
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code Valid values:
* 0x41 (LEX_RCMD_ACK packet)
* 0x42 (LEX_RCMD_NAK packet)
* 0x43 (LEX_RCMD_REJ packet)
Identifier The same value as that sent by the
LEX_RCMD_REQUEST packet
Length 12 octets
Option-Type 0x04 (Disable LAN Extension Ethernet
Interface)
Option-Flags None
Option-Length 4 octets
Option-Data None
7.0 Enable LAN Extension Ethernet Interface
The host router sends a LEX_RCMD_ REQUEST with an Option-Type of 0x05
to the LAN extension interface unit to enable the LAN extension
Ethernet interface. This remote command option allows LAN traffic to
flow into the LAN extension interface unit after the interface has
been disabled.
7.1 LEX RCMD_REQUEST - Enable LAN Extension Ethernet Interface
Figure 10 shows a frame format summary of a LEX_RCMD_REQUEST packet
for an Enable LAN Extension Ethernet Interface remote command option.
The host router transmits the fields from left to right.
Figure 10 LEX_RCMD_REQUEST Packet Frame Format - Enable LAN Extension
Ethernet Interface
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
LAN Extension Interface Remote Command Options
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option-Type | Option-Flags | Option-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
Summary Field Descriptions
For complete descriptions of the fields in the PPP Header, the LAN
Extension Interface Protocol Header, and the LAN Extension Interface
Remote Command Option, refer to the "Remote Command Options" section
earlier in this document. Table 10 provides a summary of these fields
when sending a LEX_RCMD_REQUEST packet that enables the LAN extension
Ethernet interface.
Table 10 Field Values for LEX_RCMD_REQUEST Packet -
Enable LAN Extension Ethernet Interface
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code 0x40 (LEX_RCMD_REQUEST packet)
Identifier Valid values: 0x01-0xFF
Length 12octets
Option-Type 0x05 (Enable LAN Extension Ethernet
Interface)
Option-Flags None
Option-Length 4 octets
Option-Data None
7.2 Response Packets - Enable LAN Extension Ethernet Interface
LEX_RCMD_ACK, LEX_RCMD_NAK, and LEX_RCMD-REJ packets are valid
responses to the Enable LAN Extension Ethernet Interface
LEX_RCMD_REQUEST packet. Refer to the "Conditions for Sending PPP-LEX
Packets" section earlier in this document for more information on
when the LAN extension interface unit sends each of these response
packets. Note that the LAN extension interface unit sends the
LEX_RCMD_ACK packet after enabling the interface.
The frame format of the response packets mirrors that of the request.
Table 11 summarizes the field values of Enable LAN Extension Ethernet
Interface LEX_RCMD_ACK, LEX_RCMD_NAK, and LEX_RCMD_REJ packets.
Table 11 Field Values for Response Packets -
Enable LAN Extension Ethernet Interface
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code Valid values:
* 0x41 (LEX_RCMD_ACK packet)
* 0x42 (LEX_RCMD_NAK packet)
* 0x43 (LEX_RCMD_REJ packet)
Identifier The same value as that sent by the
LEX_RCMD_REQUEST packet
Length 12 octets
Option-Type 0x05 (Enable LAN Extension Ethernet
Interface)
Option-Flags None
Option-Length 4 octets
Option-Data None
8.0 Reboot LAN Extension Interface Unit
The host router sends a LEX_RCMD_REQUEST packet with an Option-Type
of 0x06 to the LAN extension interface unit to cause the LAN
extension interface unit to reboot itself. The Option-Flags field
specifies the boot mode for the LAN extension interface unit. There
are two boot modes:
* The first boot mode (Option-Flag 0x00) is the default. The
default boot mode causes the LAN extension interface unit to
check for a valid Flash image and to boot from it if it exists.
If a valid Flash image does not exist, the default boot mode
causes the LAN extension interface unit to boot from the PROM
image. Similarly, if the Flash image is bad, then the LAN
extension interface unit recovers by booting from the PROM image.
* The second boot mode (Option-Flag 0x01) forces the LAN extension
interface unit to boot from the PROM image.
8.1 LEX RCMD_REQUEST - Reboot LAN Extension Interface Unit
Figure 11 shows a frame format summary of a LEX_RCMD_REQUEST packet
for a Reboot LAN Extension Interface Unit remote command option. The
host router transmits the fields from left to right.
Figure 11 LEX_RCMD_REQUEST Packet Frame Format -
Reboot LAN Extension Interface Unit
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
LAN Extension Interface Remote Command Options
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option-Type | Option-Flags | Option-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
Summary Field Descriptions
For complete descriptions of the fields in the PPP Header, the LAN
Extension Interface Protocol Header, and the LAN Extension Interface
Remote Command Option, refer to the "Remote Command Options" section
earlier in this document. Table 12 provides a summary of these fields
when sending a LEX_RCMD_REQUEST packet that instructs the LAN
extension interface unit to reboot.
Table 12 Field Values for LEX_RCMD_REQUEST Packet -
Reboot LAN Extension Interface Unit
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code 0x40 (LEX_RCMD_REQUEST packet)
Identifier Valid values: 0x01-0xFF
Length 12 octets
Option-Type 0x06 (Reboot LAN Extension Interface Unit)
Option-Flags Valid values:
* 0x00 - Reboot from Flash image if it
exists. If not, reboot from PROM. (This
value does not force the LAN extension
interface unit to reboot from PROM.)
* 0x01 - Reboot from PROM explicitly.
Option-Length 4 octets
Option-Data None
8.2 Response Packets - Reboot LAN Extension Interface Unit
LEX_RCMD_ACK, LEX_RCMD_NAK, and LEX_RCMD-REJ packets are valid
responses to the Reboot LAN Extension Interface Unit LEX_RCMD_REQUEST
packet. Refer to the "Conditions for Sending PPP-LEX Packets" section
earlier in this document for more information on when the LAN
extension interface unit sends each of these response packets. Note
that the LAN extension interface unit reboots after sending the
LEX_RCMD_ACK packet.
The frame format for the response packets mirrors that of the
request. Table 13 summarizes the field values for Reboot LAN
Extension Interface Unit LEX_RCMD_ACK, LEX_RCMD_NAK, and LEX_RCMD_REJ
packets.
Table 13 Field Values for Response Packets -
Reboot LAN Extension Interface Unit
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code Valid values:
* 0x41 (LEX_RCMD_ACK packet)
* 0x42 (LEX_RCMD_NAK packet)
* 0x43 (LEX_RCMD_REJ packet)
Identifier The same value as that sent in the
LEX_RCMD_REQUEST packet
Length 12 octets
Option-Type 0x06 (Reboot LAN Extension Interface Unit)
Option-Flags Valid values:
* 0x00 - Reboot from Flash image if it
exists. If not, reboot from PROM. (This
value does not force the LAN extension
interface unit to reboot from PROM.)
* 0x01 - Reboot from PROM explicitly.
Option-Length 4 octets
Option-Data None
9.0 Request Statistics
The host router issues a LEX_RCMD_REQUEST packet with an Option-Type
of 0x07 to obtain statistics information from the LAN extension
interface unit. The host router may want statistics information about
the following:
* Serial interface only
* LAN interface only
* Both the serial and LAN interfaces
The host router may also send a Statistics Request LEX_RCMD_REQUEST
packet to reset statistics in the LAN extension interface unit.
9.1 LEX RCMD_REQUEST - Request Statistics
Figure 12 shows a summary frame format of a LEX_RCMD_REQUEST packet
for a Statistics Request remote command option. The host router
transmits the fields from left to right.
Figure 12 LEX_RCMD_REQUEST Packet Frame Format - Request Statistics
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
LAN Extension Interface Remote Command Option
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 0 1 2
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option-Type | Option-Flags | Option-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
Summary Field Descriptions
For complete descriptions of the fields in the PPP Header, the LAN
Extension Interface Protocol Header, and the LAN Extension Interface
Remote Command Option, refer to the "Remote Command Options" section
earlier in this document. Table 14 provides a summary of these fields
when sending a LEX_RCMD_REQUEST packet that requests statistics of
the LAN extension interface unit.
Table 14 Field Values for LEX_RCMD_REQUEST Packet -
Request Statistics
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code 0x40 (LEX_RCMD_REQUEST packet)
Identifier Valid values: 0x01-0xFF
Length 12 octets
Option-Type 0x07 (Request Statistics)
Option-Flags Valid values:
* 0x01 - Resets serial statistics in the LAN
extension interface unit
* 0x02 - Returns serial statistics from the
LAN extension interface unit
* 0x04 - Returns LAN statistics from the LAN
extension interface unit
* 0x08 - Resets LAN statistics in the LAN
* extension interface unit
If both serial and LAN statistics are
desired, the corresponding bits of this
field should be set (that is, 0x06). The
serial interface statistics appear in the
response packet before the LAN statistics.
Option-Length 4 octets
Option-Data None
9.2 LEX RCMD_ACK - Request Statistics
The normal response to a Statistics Request LEX_RCMD_REQUEST packet
is a LEX_RCMD_ACK packet. This acknowledgment packet has an Option-
Type, an Option-Flags, and an Option-Length field followed by one or
two blocks of statistics data. The value in the Option-Flags field
indicates whether the packet has one or two blocks of statistics. For
more information on these values, see the following "Summary Field
Descriptions" section.
The frame format for the Statistics Request LEX_RCMD_ACK packet
follows. The LAN extension interface unit transmits the fields from
left to right.
Figure 13 LEX_RCMD_ACK Packet Frame Format - Request Statistics
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
LAN Extension Interface Remote Command Options
<--------------------------------
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option-Type | Option-Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1)
----------------------------------------------->
6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option-Length | Option-Data |
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2)
Where the Option-Data fields contains one or both of the following
statistics blocks:
Serial Interface Statistics Block:
(32 bits)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Packets Received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of CRC Erros |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Framing Errors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Overruns |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Packets Dropped |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Frame Aborts |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Packets in Error |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Packets Dropped Due to Lack of |
| Buffer Descriptors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Time of Last Packet Received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Average Data Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Average Packet Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Octets Received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Input, Number of Packets Dropped Due to No Buffers|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets Transmitted |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets with Error Transmissions|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Under-run Errors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets in Low Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Size of Low Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets Dropped in Low Priority |
| Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets in Normal Priority Queue|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Size of Normal Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets Dropped in Normal |
| Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets in Medium Priority Queue|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Size of Medium Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets Dropped in |
| Medium Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets in High Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Size of High Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Packets Dropped in High |
| Priority Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Time of Last Packet Transmitted |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Carrier Transitions |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Transmitted Data Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Serial Line Output, Number of Octets Transmitted |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Lan Interface Statistics Block:
(32 bits)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Packets Received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Packets Received with CRC Errors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Packets Received with Framing Errors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Overruns |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Packets Dropped Due to Congestion |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Frame Aborts |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Broadcast Packets Received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Packets Received with Errors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Packets Dropped Due to Lack of Buffer |
| Descriptors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Runts (Too Small Packets) Received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Time of Last Packet Received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Average Data Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Average Packet Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Octets Received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Input, Number of Packets Dropped Due to Lack of Buffers |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Number of Packets Transmitted |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Number of Packets Transmitted with Errors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Number of Under-runs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Number of Collisions (Ethernet) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Number of Packets in Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Queue Size |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Number of Packets Dropped in Queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Time of Last Packet Transmitted |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Transmit Data Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Transmit Packet Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN Output, Number of Octets Transmitted |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LAN, Number of Interface Resets |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note: Counts are cumulative since last counter reset. Time stamps
are in milliseconds since last given event. Packet rates are in
packets per second (averaged).
Summary Field Descriptions
For complete descriptions of the fields in the PPP Header, the LAN
Extension Protocol Header, and the LAN Extension Remote Command
Option, refer to the "Remote Command Options" section earlier in this
document. The following table provides a summary of these fields for
a LEX_RCMD_ACK packet that sends statistics to the host router.
Table 15 Field Values for LEX_RCMD_ACK Packet - Request Statistics
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code 0x41 (LEX_RCMD_ACK packet)
Identifier The same value as that sent by the
LEX_RCMD_REQUEST packet
Length Minimum length = 120 octets
Maximum length = 140 octets
Option-Type 0x07 (Request Statistics)
Option-Flags The LAN extension interface unit always sets
this field to reflect the actions taken in
response to the LEX_RCMD_ACK packet. Valid
values:
* 0x01 - Reset serial statistics in the LAN
extension interface unit
* 0x02 - Return serial statistics from the
LAN extension interface unit
* 0x04 - Return LAN statistics from the LAN
extension interface unit
* 0x08 - Reset LAN statistics in the LAN
extension interface unit
If both serial and LAN statistics are
returned, the corresponding bits of this
field should are set (that is, 0x06). The
serial interface statistics appear in the
response packet before the LAN statistics.
Option-Length Minimum length = 116 octets
Maximum length = 136 octets
Option-Data The Serial Interface Statistics Block, the
LAN Interface Statistics Block, or both the
Serial Interface and LAN Interface
Statistics blocks. When the Option-Data
contains both blocks, the Serial Interface
Block precedes the LAN Interface Block.
Statistics values that the LAN extension
interface unit does not collect/support
are retuned with a value of zero.
Implementation Notes
If the LAN extension interface unit does not implement the capability
of sending the serial and LAN interface statistics blocks separately,
the implementation may always return both statistics blocks (with the
Option-Flags and Option-Length fields containing the appropriate
corresponding values).
An implementation, such as a Token Ring LAN implementation, can
collect a different set of statistics than shown above by defining a
new statistics request type remote command option.
9.3 LEX RCMD_NAK/LEX RCMD_REJ - Request Statistics
The LAN extension interface unit sends a LEX_RCMD_NAK packet when the
Statistics Request LEX_RCMD_REQUEST packet did not specify the type
of statistics the host router wants. That is, the request's Option-
Flags field equals zero.
Refer to the "Conditions for Sending PPP-LEX Packets" section earlier
in this document for information on when the LAN extension interface
unit sends a Request Statistics LEX_RCMD_REJ packet.
The frame format for the LEX_RCMD_NAK and LEX_RCMD_REJ packets is the
same as that of the Statistics Request LEX_RCMD_REQUEST packet. Table
16 summarizes the appropriate field values for the Statistics Request
LEX_RCMD_NAK and LEX_RCMD_REJ packets.
Table 16 Field Values for LEX_RCMD_NAK/LEX_RCMD_REJ Packets -
Request Statistics
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code Valid values:
* 0x42 (LEX_RCMD_NAK packet)
* 0x43 (LEX_RCMD_REJ packet)
Identifier The same value as that sent by the
LEX_RCMD_REQUEST packet
Length 12 octets
Option-Type 0x07 (Request Statistics)
Option-Flags The same value as that sent by the
LEX_RCMD_REQUEST packet
Option-Length 4 octets
Option-Data None
10.0 Download Request
The host router sends a LEX_RCMD_REQUEST packet with an Option-Type
of 0x08 to alert the LAN extension interface unit that the host
router will be issuing a software download to Flash memory. When the
LAN extension interface unit acknowledges the command, the host
router starts sending download data.
10.1 LEX RCMD_REQUEST - Download Request
Figure 14 shows a summary frame format of a LEX_RCMD_REQUEST packet
for a Download Request remote command option. The host router
transmits the fields from left to right.
Figure 14 LEX_RCMD_REQUEST Packet Frame Format - Download Request
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
LAN Extension Interface Remote Command Option
<--------------------------------
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option-Type | Option-Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1)
----------------------------------------------->
6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option-Length | Option-Data |
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2)
Where the Option-Data field contains the following fields:
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Block Number (16 bits) | File Size (32 bits)....
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Filename (Max. 64 octets).......
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Summary Field Descriptions
For a complete description of the fields in the PPP Header, the LAN
Extension Interface Protocol Header, and the LAN Extension Interface
Remote Command Option, refer to the "Remote Command Options" section
earlier in this document. Table 17 provides a summary of these fields
when sending a LEX_RCMD_REQUEST packet that informs the LAN extension
interface unit of an upcoming software download to Flash memory.
Table 17 Field Values for LEX_RCMD_REQUEST Packet - Download Request
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code 0x40 (LEX_RCMD_REQUEST packet)
Identifier Valid values: 0x01-0xFF
Length Variable depending on size of filename in
the Filename field. Valid range:
Minimum length = 19 octets
Maximum length = 82 octets
Option-Type 0x08 (Download Request)
Option-Flags None
Option-Length Variable depending on size of filename in
the Filename field. Valid range:
Minimum length = 11 octets
Maximum length = 74 octets
Option-Data Block Number, File Size, and Filename of
the code/image to be downloaded. See the
following "Option-Data Field Descriptions"
section for details.
Option-Data Field Descriptions
The Option-Data field contains the following fields:
* Block Number
The Block Number field contains a value that identifies a contiguous
group of code bits to be downloaded to the LAN extension interface
unit. In the LEX_RCMD_REQUEST packet, the Block Number is always
zero.
* File Size
The File Size field contains the size (in octets) of the code to be
downloaded to the LAN extension interface unit.
* Filename
The Filename field contains the name of the image to be transferred
to the LAN extension interface unit.
10.2 Response Packets - Download Request
The following packets are valid responses to a Download Request
LEX_RCMD_REQUEST packet:
* LEX_RCMD_ACK - Download Request
Refer to the "Conditions for Sending PPP-LEX Packets" section earlier
in this document for more information on when the LAN extension
interface unit sends this packet.
* LEX_RCMD_NAK - Download Request
The LAN extension interface unit sends a Download Request
LEX_RCMD_NAK packet when the LAN Extension interface unit is
currently programming Flash, when the File Size field value in the
request is greater than the unit's available Flash bytes, when the
LAN extension interface unit is out of memory, or when the Block
Number field value in the request is not zero.
* LEX_RCMD_REJ - Download Request
Refer to the "Conditions for Sending PPP-LEX Packets" section earlier
in this document for more information on when the LAN extension
interface unit sends this packet.
Table 18 summarizes the field values of the Download Request
LEX_RCMD_ACK, LEX_RCMD_NAK, and LEX_RCMD_REJ packets.
Table 18 Field Values for Response Packets - Download Request
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code Valid values:
* 0x41 (LEX_RCMD_ACK packet)
* 0x42 (LEX_RCMD_NAK packet)
* 0x43 (LEX_RCMD_REJ packet)
Identifier The same value as that sent by the
LEX_RCMD_REQUEST packet
Length The same value as that sent by the
LEX_RCMD_REQUEST packet
Option-Type 0x08 (Download Request)
Option-Flags None
Option-Length The same value as that sent by the
LEX_RCMD_REQUEST packet
Option-Data Block Number, File Size, and Filename of
the code/image to be downloaded.
11.0 Download Data
Once the host router receives a Download Request LEX_RCMD_ACK packet
from the LAN extension interface unit, the host router downloads the
data to be written to Flash memory by sending a LEX_RCMD_REQUEST
packet with an Option-Type of 0x09. The host router sends multiple
Download Data LEX_RCMD_REQUEST packets, each with 512 octets of
Option-Data containing the binary data to be programmed into Flash
memory.
A packet containing Option-Data with less than 512 octets signals the
end of the download data (that is, the end of tile). If the size of
the file being downloaded is an even multiple of 512 bytes, then the
last packet transferred should have an Option-Length of 6. That is,
the last packet transferred should have Option-Data containing the
Block Number field value but no data. A Block Number field value
without data alerts the LAN extension interface unit that this is the
last block to be transmitted.
11.1 LEX RCMD_REQUEST - Download Data
The frame format for the Download Data LEX_RCMD_REQUEST packet is
similar to a TFTP frame format. Figure 15 shows a summary frame
format. The host router transmits the fields from left to right.
Figure 15 LEX_RCMD_REQUEST Packet Frame Format - Download Data
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1) (2)
LAN Extension Interface Remote Command Option
<--------------------------------
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option-Type | Option-Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) (1)
----------------------------------------------->
6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option-Length | Option-Data |
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2)
Where the Option-Data field contains the following fields:
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Block Number (16 bits) | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Binary Download Data (Max. 512 octets)..... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Summary Field Descriptions
For a complete descriptions of the fields in the PPP Header, the LAN
Extension Interface Protocol Header, and the LAN Extension Interface
Remote Command Option, refer to the "Remote Command Options" section
earlier in this document. The following table provides a summary of
these fields when sending a LEX_RCMD_REQUEST packet that download
software to the LAN extension interface unit.
Table 19 Field Values for LEX_RCMD_REQUEST Packet - Download Data
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code 0x40 (LEX_RCMD_REQUEST packet)
Identifier Valid values: 0x01-0xFF
Length Minimum length = 14 octets
Maximum length = 526 octets
Option-Type 0x09 (Download Data)
Option-Flags None
Option-Length Minimum length = 6 octets (signals end of
data transfer for a file with a file size
of an even multiple of 512 bytes)
Maximum length = 518 octets
Option-Data Block Number and Download Data. See the
following "Option-Data Field Descriptions"
section for details.
Option-Data Field Descriptions
The following Option-Data fields provide the LAN extension interface
unit with download data:
* Block Number
The Block Number identifies the contiguous group of code bits to be
downloaded. The host router automatically generates this number. The
first Download Data packet gets a block number of one. The host
router increments this Block Number value by one with every Download
Data LEX_RCMD_REQUEST packet sent to the LAN extension interface
unit. The maximum value of the Block Number is dependent on the
unit's Flash memory size.
* Download Data
The Download Data are the actual code bits being downloaded to the
LAN extension interface unit. A maximum of 512 octets of download
data can sent in one Download Data LEX_RCMD_REQUEST packet.
11.2 Response Packets - Download Data
The following packets are valid responses to a Download Data
LEX_RCMD_REQUEST packet:
* LEX_RCMD_ACK - Download Data
Refer to the "Conditions for Sending PPP-LEX Packets" section earlier
in the document for more information on this packet.
* LEX_RCMD_NAK - Download Data
The LAN extension interface unit sends a Download Data LEX_RCMD_NAK
packet when the LAN extension interface unit is not in the proper
state or when accepting the data will over-run the download buffer.
* LEX_RCMD_REJ - Download Data
Refer to the "Conditions for Sending PPP-LEX Packets" section earlier
in the document for more information on this packet.
Table 20 summarizes the field values of the Download Data
LEX_RCMD_ACK, LEX_RCMD_NAK, and LEX_RCMD_REJ packets.
Table 20 Field Values for Response Packets - Download Data
Field Value
Address/Control 0xFF03 (Broadcast address/Unnumbered
information)
Protocol-Type 0x8041 (Control packet)
Code Valid values:
* 0x41 (LEX_RCMD_ACK packet)
* 0x42 (LEX_RCMD_NAK packet)
* 0x43 (LEX_RCMD_REJ packet)
Identifier The same value as that sent by the
LEX_RCMD_REQUEST packet
Length 14 octets
Option-Type 0x09 (Download Data)
Option-Flags None
Option-Length 6 octets
Option-Data Block Number only
12.0 Download Status
Upon completion of a Download Data sequence, the host router issues a
LEX_RCMD_REQUEST packet with an Option-Type of 0x0A to request status
of the success or failure of the download. A bad checksum of the
image or a malfunctioning Flash memory could cause the download to
fail.
12.1 LEX RCMD_REQUEST - Download Status
Figure 16 shows the frame format summary of a LEX_RCMD_REQUEST packet
for a Download Status remote command option. The host router
transmits the fields from left to right.
Figure 16 LEX_RCMD_REQUEST Packet Frame Format - Download Status
PPP Header
<-------------------------------------------------------------->
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xFF03 | Protocol-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(2 octets) (2)
LAN Extension Interface Protocol Header
<-------------------------------------------------------------->