The ATM interface does not support sending F4 segment
loopback cells, but it does respond to F4 segment loopback cells that
it receives.
F4 OAM flows need their own channel, and they are
identified by the VCI on which they are sent or received. The following
VCIs are reserved for F4 OAM flows for each virtual path, and you
cannot open PVCs on them:
VCI 3—For segment F4 flows
VCI 4—For end-to-end F4 flows
Note:
You cannot enable both loopback cells and CC cells at the same
time.
To set up F4 OAM:
Enable F4 OAM on an interface or VP. The router enables
F4 OAM at the interface level unless you specify a VPI. This example
opens both segment and end-to-end F4 OAM circuits on VPI 10.
host1(config-if)#atm oam 10
(Optional) Enable only segment or end-to-end loopback.
host1(config-if)#atm oam 10 seg-loopback
host1(config-if)#atm oam 10 end-loopback
(Optional) To cause the interface to generate end-to-end
loopback cells in addition to receiving and responding to them, set
the loopback timer.
host1(config-if)#atm oam 10 seg-loopback cc
source
atm oam
Use to configure F4 OAM on an interface or circuit. F4
OAM is configured at the interface level unless you specify a VPI.
To open F4 OAM on either a segment or end-to-end basis,
use the following keywords:
seg-loopback—Enables
F4 segment OAM
end-loopback—Enables
F4 end-to-end OAM
Note:
If you do not specify either segment or end-to-end loopback,
the command applies to both end-to-end and segment F4 OAM circuits.
To configure CC cell flow on the PVC, use the following
keywords:
both—Enables the PVC
as both the source and the sink endpoints.
sink—Enables the PVC
as the sink endpoint.
source—Enables the PVC
as the source endpoint.
loopback-timer—When
F4 OAM is enabled, the interface or circuit accepts and responds to
F4 OAM cells. However, to generate F4 loopback cells, you must configure
the loopback timer in the range 1–600 seconds. This timer represents
the frequency with which F4 loopback cells are transmitted. You can
set the loopback timer only for end-to-end loopback.
Example 1—Opens both F4 end-to-end and segment OAM
circuits for VPI 8
host1(config-if)#atm oam 8
Example 2—Opens the F4 end-to-end OAM circuit for
VPI 10 and enables sending F4 end-to-end loopback cells on the circuit
at a frequency of 20 seconds
Example 3—Opens both F4 end-to-end and segment OAM
circuits on all VPs on this interface
host1(config-if)#atm oam
Example 4—Opens F4 segment OAM circuits on all VPs
on this interface
host1(config-if)#atm oam seg-loopback
Example 5—Opens F4 end-to-end loopback on VPI 12
host1(config-if)#atm oam 12 end-loopback
Example 6—Opens an F4 segment OAM circuit for VPI
8 and enables CC cell generation on the segment
host1(config-if)#atm oam 8 seg-loopback cc
source
Use the no version to delete
F4 OAM circuits. Using the options, you can delete all F4 OAM circuits
on the interface, segment or end-to-end F4 OAM circuits, or F4 OAM
circuits on a specific VPI.
Example 1—Deletes all F4 OAM circuits on the interface
host1(config-if)#no atm oam
Example 2—Deletes all F4 segment OAM circuits on
the interface
host1(config-if)#no atm oam segment
Example 3—Deletes the F4 end-to-end OAM circuit
on VPI 8
F5 OAM flows run over existing PVCs. The ATM interface
does not support sending F5 segment loopback cells, but it does respond
to F5 segment loopback cells that it receives.
Note:
You cannot enable both loopback cells and CC cells at the same
time.
To set up F5 OAM:
To enable VC integrity, which causes the ATM interface
to periodically send F5 end-to-end loopback cells over a VC, use the oam keyword with the atm pvc command.
You can include the frequency (in seconds) with
which the router sends F5 end-to-end loopback cells.
(Optional) To enable CC cell flows on a circuit, use the cc keyword with the atm pvc command. You can enable cell flows on a segment or end-to-end basis,
and you can enable the PVC as a sink, source, or both a sink and a
source.
host1(config-if)#atm pvc 50 0 50 aal5snap
oam cc end-to-end sink
When you issue the appropriate shutdown command to change the administrative status of the corresponding
ATM interface, ATM AAL5 interface, or ATM 1483 subinterface from
enabled to disabled, the router automatically disables all F5 OAM
services configured on the associated VC. For more information, see Automatic Disabling of F5 OAM Services.
atm pvc
Use the atm pvc command with
the oam keyword to set up the PVC to periodically
transmit F5 end-to-end loopback cells over a VC.
You can use the oam keyword
only if you specify one of the following encapsulation types:
aal5snap
aal5mux ip
aal5autoconfig
The oam keyword is not available
with the aal5all, aal0, or ilmi
Optionally, you can configure the time interval in the
range 1–600 seconds between transmissions of OAM F5 end-to-end
loopback cells.
Use the following keywords to enable and configure CC
cell flows:
end-to-end—Opens an
end-to-end CC cell flow
segment—Opens a segment
CC cell flow
sink—Enables this VC
as a sink point (cell receiver)
source—Enables this
VC as the source point (cell generator)
both—Enables this VC
as both a sink point and a source point
Example 1—Enables F5 end-to-end loopback cells
host1(config-if)#atm pvc 20 20 20 aal5snap
oam
Example 2—Enables end-to-end CC cell flow and enables
the PVC as the sink
host1(config-if)#atm pvc 5 0 5 aal5autoconfig
oam cc end-to-end sink
Use the no version of the atm pvc command without the oam keyword to disable F5 OAM on the PVC and without the cc keyword to disable
CC cell flows on the PVC. For example, the following command disables
CC cell flow configured in Example 2.
Note:
Because the router is a connection endpoint, the default loopback
location ID is all 1s (ones). This command enables you to specify
a nondefault value.
atm oam loopback-location
Use to set the location ID of the ATM interface. The location
ID is a 4-octet field, and the default value is all 1s (ones).
You can set a specific value to identify this ATM interface
as the intended recipient of OAM loopback cells.
You can also set the location ID to all 0s (zeros).
For information about how the router handles
loopback cells based on location ID, see Table 6.
You can use the atm oam flush command to enable the OAM flush feature for an ATM interface. When
OAM flush is enabled, the router ignores all OAM cells received on
the interface, and stops sending OAM cells on this interface.
You can also issue the atm oam flush command with the optional alarm-cells keyword to cause the router to ignore only AIS and RDI cells and
to accept all other OAM cells. This is useful in diagnostic situations
when you might want to exclude alarm conditions.
Note:
The OAM flush feature is supported on all E Series ATM module
combinations.
atm oam flush
Use to configure the router to ignore all OAM cells received
on an ATM interface, and to stop sending OAM cells on this interface.
To cause the router to ignore only AIS and RDI cells and
to accept all other OAM cells, use the alarm-cells keyword.
Example
host1(config-if)#atm oam flush
Use the no version to disable
OAM flush on the interface.
Before you can run ATM ping, you need to add a PVC for
the VPI and VCI over which you run the ping.
Because ATM ping requires the receipt of OAM cells, make
sure that the receipt and transmission of OAM cells is not disabled
(using atm oam flush ). To reenable the receipt and
transmission of OAM cells, enter no atm oam flush.
Disabling receipt of OAM cells during a ping operation
stops all outstanding ping operations. You need to manually restart
the ping operation after receipt of OAM cells for the interface is
enabled.
Because ATM ping is a dynamic (on-demand) operation, none
of the configuration related to ATM ping is saved. To avoid acquiring
excessive bandwidth for OAM, the number of outstanding ping operations
on each interface is limited to 12.
ping atm interface atm
Use to send loopback cells from an ATM interface or circuit.
The VPI and VCI fields determine the type of loopback
cells used for the ping operation. By default F5 end-to-end loopback
OAM cells are used.
To send F4 segment loopback cells, set the VCI to 3.
To send F4 end-to-end loopback cells, set the VCI to 4.
Use the end-loopback keyword
to send the ping to the connection endpoint.
Use the seg-loopback keyword
to send the ping to the first segment point (for example, the next
neighbor switch).
Use the destination option to specify
the value of the location ID included in the loopback cell. The location
ID is a 16-octet field, and the destination portion is 4 octets. You
can set the location ID to a specific destination or to 0s (zeros)
or 1s (ones).
If you set the destination to 0, the loopback location
ID in the loopback cell is initialized to all 0s, and each segment
point in the network responds to the ping.
If you set the destination to 1s, the loopback location
ID in the loopback cell is initialized to all 1s, and only the connection
endpoint responds to the ping.
If you use the default value of 0xFFFFFFFF, the loopback
location ID in the loopback cell is initialized to all 1s.
For information about how the router handles loopback
cells based on location ID, see Table 6.
The count keyword sets the
number of OAM loopback cells to send to the destination. The default
value is 5. The maximum is 32.
The timeout keyword sets the
amount of time to wait for a response to the sent OAM loopback cell.
The default value is 5 seconds.
The following characters can appear in the display after
the ping command has been issued:
!—Each exclamation point indicates that a reply
was received
.—Each period indicates that the ping timed out
while waiting for a reply
Example 1—This example generates end-to-end loopback
cells for VPI=0 and VCI=105 on ATM interface 2/0. The count value
is 5 OAM loopback cells, and the timeout value is 2 seconds.
Success rate = 100% (5/5), round-trip min/avg/max = 0/4/10
ms
Example 2—This example generates segment loopback
cells for VPI=0 and VCI=105 on ATM interface 2/0. The destination
is set to 0xFFFFFFFF, the count value is 3 OAM loopback cells, and
the timeout value is 1 second.
