9-6
Cisco MGX 8850 Routing Switch Command Reference
Release 2.0, Part Number 78-10467-04 Rev C0, October 2001
Chapter 9
Troubleshooting Commands
addchanloop
addchanloop
Add Channel Loopback—add a loopback to a specific channel in a network test configuration.
The channel loopback tests the integrity of the connection (channel) at the local UNI or across the
network. The system returns an error message if the connection is broken or incorrect data arrives at the
end of the loopback. The maximum number of connection loopbacks that can exist on an AXSM is 256.
The addchanloop command applies to a network that is not carrying live traffic because the test is
totally intrusive. The test requires some form of a testing device to generate a cell stream. The
parameters for such a stream are the number of cells transmitted through the loop, the cell transfer rate,
and so on. (To test connection integrity in a non-destructive way while the connection carries user data,
use tstdelay on the ingress or tstconseg on the egress. These commands generate one OAM cell for each
command execution.)
A connection can have only one loopback at a time. Therefore, you cannot add a loopback for both
directions at the same time. The loopback remains until you delete it by executing delchanloop. To see
the presence of connection loopbacks on a per-port basis, use dspchanloop.
The addchanloop command lets you specify the direction of cell flow within the loop (see
Figure 9-1
):
•
In the ingress direction, the cells travel from the tester to the queueing engine on the AXSM; then
back to the tester.
•
In the egress direction, the cells travel from the tester to the local AXSM; then across the network
to the remote AXSM. At the far end, the cells go to the queueing engine then return back across the
network to the tester.
The maximum number of loopbacks that can exist on an AXSM is 256.
Figure 9-1
Connection (Channel) Loopbacks on the Ingress and Egress
Cards on Which This Command Runs
AXSM
Syntax
addchanloop <ifNumber> <vpi> <vci> <loopback mode>
Syntax Description
Tester
Ingress: mode 1
AXSM
Tester
Egress: mode 2
AXSM
AXSM
Rx
Tx
ATM
cloud
49469
ifNumber
The logical port number. The range for AXSM is 1–60.
vpi
The VPI of the connection. The range is 0–4095.