LevelOne GEL-2060 Quick guide

GEL-2060
OAM Configuration

Table of Contents
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Table of Contents
OAM Configuration ............................................................................................................................................................... 1
Table of Contents .................................................................................................................................................................. I
Chapter 1 OAM Configuration .............................................................................................................................................. 1
1.1 OAM Overview ...................................................................................................................................................... 1
1.1.1 OAM Protocol’s Attributes ......................................................................................................................... 1
1.1.2 OAM Mode ................................................................................................................................................ 2
1.1.3 Components of the OAM Packet............................................................................................................... 3
1.2 OAM Configuration Task List ................................................................................................................................. 4
1.3 OAM Configuration Tasks...................................................................................................................................... 5
1.3.1 Enabling OAM on an Interface .................................................................................................................. 5
1.3.2 Enabling Remote OAM Loopback............................................................................................................. 5
1.3.3 Configuring OAM Link Monitoring ............................................................................................................. 6
1.3.4 Configuring the Trouble Notification From Remote OAM Entity................................................................ 8
1.3.5 Displaying the Information About OAM Protocol ....................................................................................... 9
1.4 Configuration Example .......................................................................................................................................... 9
1.4.1 Network Environment Requirements ........................................................................................................ 9
1.4.2 Network Topology.................................................................................................................................... 10
1.4.3 Configuration Procedure ......................................................................................................................... 10

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Chapter 1 OAM Configuration
1.1 OAM Overview
EFM OAM of IEEE 802.3ah provides point-to-point link trouble/performance
detection on the single link. However, EFM OAM cannot be applied to EVC and
so terminal-to-terminal Ethernet monitoring cannot be realized. OAM PDU cannot
be forwarded to other interfaces. Ethernet OAM regulated by IEEE 802.3ah is a
relatively slow protocol. The maximum transmission rate is 10 frames per second
and the minimum transmission rate is 1 frame per second.
1.1.1 OAM Protocol’s Attributes
Supporting Ethernet OAM devices and OAM attributes
The Ethernet OAM connection process is called as the Discovery phase
when the OAM entity finds the OAM entity of the remote device and a
stable session will be established. During the phase, the connected
Ethernet OAM entities report their OAM mode, Ethernet OAM configuration
information and local-node-supported Ethernet OAM capacity to each other
by interacting the information OAM PDU. If the loopback configuration,
unidirectional link detection configuration and link-event configuration have
been passed on the Ethernet OAM of the two terminals, the Ethernet OAM
protocol will start working on the link layer.
Link monitoring
The Ethernet OAM conducts the link monitoring through Event Notification
OAM PDU. If the link has troubles and the local link monitors the troubles,
the local link will transmits Event Notification OAM PDU to the peer
Ethernet OAM to report the normal link event. The administrator can
dynamically know the network conditions through link monitoring. The
definition of a normal link event is shown in table 1.
Table 1 Definition of the normal link event
Normal Link Event
Definition
Period event of error signal
Specifies the signal number N as the period. The number of
error signals exceeds the defined threshold when Nsignals are
received.
Error frame event
The number of error frames exceeds the defined threshold
during the unit time.
Period event of error frame
Specifies the frame number N as the period. The number of
error frames exceeds the defined threshold when Nframes are
received.
Second frame of error
frame
Specifies that the number of seconds of the error frame
exceeds the defined threshold in the designated Msecond.

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Remote trouble indication
It is difficult to check troubles in the Ethernet, especially the case that the
network performance slows down while physical network communication
continues. OAM PDU defines a flag domain to allow Ethernet OAM entity to
transmit the trouble information to the peer. The flag can stand for the
following emergent link events:
Link Fault: The physical layer detects that the reception direction of the
local DTE has no effect. If troubles occur, some devices at the physical
layer support unidirectional operations and allows trouble notification
from remote OAM.
Dying Gasp: If an irrecoverable local error occurs, such as OAM
shutdown, the interface enters the error-disabled state and then is
shut down.
Critical Event: Uncertain critical events occur (critical events are
specified by the manufacturer).
Information OAM PDU is continuously transmitted during Ethernet OAM
connection. The local OAM entity can report local critical link events to
remote OAM entity through Information OAM PDU. The administrator thus
can dynamically know the link’s state and handle corresponding errors in
time.
Remote loopback
OAM provides an optional link-layer-level loopback mode and conducts
error location and link performance testing through non-OAM-PDU
loopback. The remote loopback realizes only after OAM connection is
created. After the OAM connection is created, the OAM entity in active
mode triggers the remote loopback command and the peer entity responses
the command. If the remote terminal is in loopback mode, all packets
except OAM PDU packets and Pause packets will be sent back through the
previous paths. Error location and link performance testing thus can be
conducted. When remote DTE is in remote loopback mode, the local or
remote statistics data can be queried and compared randomly. The query
operation can be conducted before, when or after the loopback frame is
transmitted to the remote DTE. Regular loopback check can promptly
detect network errors, while segmental loopback check can help locating
these network errors and then remove these errors.
Round query of any MIB variables described in chapter 30 of 802.3.
1.1.2 OAM Mode
The device can conduct the OAM connection through two modes: active mode
and passive mode. The device capacity in different mode is compared in table 2.
Only OAM entity in active mode can trigger the connection process, while the
OAM entity in passive mode has to wait for the connection request from the peer
OAM entity. After the remote OAM discovery process is done, the local entity in
active mode can transmit any OAM PDU packet if the remote entity is in active
mode, while the local entity’s operation in active mode will be limited if the remote
entity is in passive mode. This is because the device in active mode does not
react on remote loopback commands and variable requests transmitted by the
passive remote entity.
Table 2 Comparing device capacity in active and passive modes

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Capacity
Active Mode
Passive Mode
Initializing the Ethernet OAM discovery process
Yes
No
Responding to the OAM discovery initialization
process
Yes
Yes
Transmitting the Information OAM PDU packet
Yes
Yes
Permitting to transmit the Event Notification OAM
PDU packet
Yes
Yes
Allowing to transmit the Variable Request OAM
PDU packet
Yes
No
Allowing to transmit Variable Response OAM PDU
packet
Yes
Yes
Allowing to transmit the Loopback Control OAM
PDU packet
Yes
No
Responding to Loopback Control OAM PDU
Yes，but the peer
terminal must be
in active mode.
Yes
Allowing to transmit specified OAM PDU
Yes
Yes
After the Ethernet OAM connection is established, the OAM entities at two
terminals maintain connection by transmitting the Information OAM PDU packets.
If the Information OAM PDU packet from the peer OAM entity is not received in
five seconds, the connection times out and a new OAM connection then requires
to be established.
1.1.3 Components of the OAM Packet
Figure 1 Components of the OAM packet
The following are the meanings of the fields of the OAM packet:

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Destination address: means the destination MAC address of the Ethernet
OAM packet.
Source address: Source MAC address of the Ethernet OAM packet
It is the MAC address of the transmitter terminal's port and also a unicast
MAC address.
Length/Type: Always adopts the Type encoding. The protocol type of the
Ethernet OAM packet is 0x8809.
Subtype：The subtype of the protocol for Ethernet OAM packets is 0x03.
Flags: a domain where the state of Ethernet OAM entity is shown
Code: a domain where the type of the OAMPDU packet is shown
Data/Pad: a domain including the OAMPDU data and pad values
FCS: checksum of the frame
Table 3 Type of the CODE domain
CODE
OAMPDU
00
Information
01
Event Notification
02
Variable Request
03
Variable Response
04
Loopback Control
05-FD
Reserved
FE
Organization Specific
FF
Reserved
The Information OAM PDU packet is used to transmit the information about the
state of the OAM entity to the remote OAM entity to maintain the OAM connection.
The Event Notification OAMPDU packet is used to monitor the link and report the
troubles occurred on the link between the local and remote OAM entities.
The Loopback control OAMPDU packet is mainly used to control the remote
loopback, including the state of the OAM loopback from the remote device. The
packet contains the information to enable or disable the loopback function. You
can open or shut down the remote loopback according to the contained
information.
1.2 OAM Configuration Task List
Enabling OAM on an interface
Enabling remote OAM loopback

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Configuring OAM link monitoring
Configuring the trouble notification from remote OAM entity
Displaying the information about OAM protocol
1.3 OAM Configuration Tasks
1.3.1 Enabling OAM on an Interface
Run the following command to enable OAM:
Proced
ure
Command
Purpose
Step1
config
Enters the global configuration mode.
Step2
interface intf-type intf-id
Enters the interface configuration mode.
Step3
ethernet oam
Enables Ethernet OAM on an interface.
Step4
ethernet oam [max-rate oampdus |
min-rate seconds | mode {active |
passive} | timeout seconds]
Configures optional OAM parameters:
The max-rate parameter is used to configure
the maximum number of OAMPDUs
transmitted per second. It ranges between 1
and 10 and its default value is 10.
The min-rate parameter is used to configure
the minimum transmission rate of OAMPDU.
Its unit is second. It ranges between 1 and 10
and its default value is 1.
The mode {active | passive} parameter is
used to set the mode of OAM. The OAM
connection can be established between two
interfaces only when at least one interface is
in active mode.
The timeout parameter is used to set the
timeout time of the OAM connection. It ranges
between 1 and 30 seconds and its default
value is 1 second.
You can run no Ethernet oam to shut down the OAM function.
The remote OAM loopback cannot be enabled on the physical interface that
belongs to the aggregation interface.
1.3.2 Enabling Remote OAM Loopback
The procedure to enable remote loopback on an interface is shown in the
following table:
Proced
ure
Command
Purpose

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Step1
config
Enters the global configuration mode.
Step2
interface intf-type intf-id
Enters the interface configuration mode.
Step3
ethernet oam remote-loopback
{supported | timeout seconds}
Configures optional loopback parameters from the
remote OAM:
The supported parameter is used to enable
an interface to support the remote loopback of
Ethernet OAM. Remote loopback is not
supported by default.
The timeout parameter is used to configure
the timeout time of remote loopback. It ranges
between 1 and 10 and its default value is 2.
Step4
exit
Exits from interface configuration mode.
Step5
exit
Exits from the global configuration mode.
Step6
ethernet oam remote-loopback
{start | stop} interface intf-type
intf-id
Enables or disables remote loopback on an
interface.
The remote OAM loopback cannot be enabled on the physical interface that
belongs to the aggregation interface.
1.3.3 Configuring OAM Link Monitoring
You can configure the low threshold and the high threshold of OAM link
monitoring.
The procedure to configure the OAM link monitoring on an interface is shown in
the following table:
Procedure
Command
Purpose
Step1
config
Enters the global configuration mode.
Step2
interface intf-type intf-id
Enters the interface configuration mode.
Step3
ethernet oam link-monitor
supported
Enables link monitoring on an interface. The link
monitoring is supported by default.
Step4
ethernet oam link-monitor
symbol-period {threshold {high
{ symbols |none} | low
{symbols}} | window symbols}
Sets the high and low threshold of the periodical
event of the error signal, which triggers the error
link events.
The threshold high parameter is used to configure
the high threshold. Its unit is signal number. It
ranges between 1 and 65535 and its default value
is none.
The threshold high parameter is used to configure
the low threshold. Its unit is signal number. It ranges
between 0 and 65535 and its default value is 1.
The window parameter is used to configure the
window size of the round-query period. The unit of
the window size is the number of the 100M signal.
The window size ranges between 10 and 600 on a

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1000M Ethernet interface and its default value is 10
in this case, while the window size ranges between
1 and 60 on a 100M Ethernet interface and its
default value is 1 in this case.
Step5
ethernet oam link-monitor
frame {threshold {high
{ symbols |none} | low
{symbols}} | window symbols}
Sets the high and low thresholds of the error frame
event, which triggers the link events of error frame.
The threshold high parameter is used to configure
the high threshold. Its unit is signal number. It
ranges between 1 and 65535 and its default value
is none.
The threshold high parameter is used to configure
the low threshold. Its unit is signal number. It ranges
between 0 and 65535 and its default value is 1.
The window parameter is used to configure the
window size of the round-query period. Its unit is
second. It ranges between 1 and 60 and its default
value is 1.
Step6
ethernet oam link-monitor
frame-period {threshold {high
{ symbols |none} | low
{symbols}} | window symbols}
Sets the high and low thresholds of the period event
of error frame, which triggers the link events of error
frame period.
The threshold high parameter is used to configure
the high threshold. Its unit is signal number. It
ranges between 1 and 65535 and its default value
is none.
The threshold high parameter is used to configure
the low threshold. Its unit is signal number. It ranges
between 0 and 65535 and its default value is 1.
The window parameter is used to configure the
window size of the round-query period. The unit of
the window size is the number of the 14881 frames.
The window size ranges between 100 and 6000 on
a 1000M Ethernet interface and its default value is
100 in this case, while the window size ranges
between 10 and 600 on a 100M Ethernet interface
and its default value is 10 in this case.
Step7
ethernet oam link-monitor
frame-seconds {threshold {high
{ symbols |none} | low
{symbols}} | window symbols}
Sets the high and low thresholds of the second
event of error frame, which triggers the link events
of error frame’s second.
The threshold high parameter is used to configure
the high threshold. Its unit is signal number. It
ranges between 1 and 900 and its default value is
none.
The threshold low parameter is used to configure
the low threshold. Its unit is signal number. It ranges
between 0 and 900 and its default value is 1.
The window parameter is used to configure the
window size of the round-query period. Its unit is

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second. It ranges between 10 and 900 and its
default value is 60.
Step8
ethernet oam link-monitor
receive-crc {threshold {high
{ symbols |none} | low
{symbols}} | window symbols}
Sets the high and low thresholds of the error CRC
frame event, which triggers the link events of CRC
checksum error.
The threshold high parameter is used to configure
the high threshold. Its unit is signal number. It
ranges between 1 and 65535 and its default value
is none.
The threshold high parameter is used to configure
the low threshold. Its unit is signal number. It ranges
between 0 and 65535 and its default value is 1.
The window parameter is used to configure the
window size of the round-query period. Its unit is
second. It ranges between 1 and 180 and its default
value is 10.
Step9
ethernet link-monitor on
Enables the local link monitoring. When the link
monitoring function is supported, the local link
monitoring is automatically enabled.
1.3.4 Configuring the Trouble Notification From Remote OAM Entity
You can configure an error-disable action on an interface. The local interface will
enter the errdisabled state in the following cases:
1.The high threshold of a normal link event on a local interface is exceeded.
2. The remote interface which connects the local interface enters the errdisabled
state.
3. The OAM function on the remote interface which connects the local interface is
shut down by the administrator. The procedure to configure the remote OAM
trouble indication on an interface is shown in the following table:
Proced
ure
Command
Purpose
Step1
config
Enters the global configuration mode.
Step2
interface intf-type intf-id
Enters the interface configuration mode.
Step3
ethernet oam remote-failure
{critical-event | dying-gasp |
link-fault} action
error-disable-interface
Configures the trigger action of a remote OAM
trouble on an interface:
The critical-event parameter is used to
enable an interface to enter the errdisabled
state when an undesignated critical event
occurs.
The dying-gasp parameter is used to enable
the local interface to enter the errdisabled
state if the high threshold of a normal link
event on a local interface is exceeded or if the
remote interface which connects the local
interface enters the errdisabled state or if the
OAM function on the remote interface which
connects the local interface is shut down by