Cisco Systems Cisco MGX 8850 addchanloop

9-6
Cisco MGX 8850 Routing Switch Command Reference
Release 2.0, Part Number 78-10467-04 Rev C0, October 2001
Chapter9 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 me ssage if the connection is broken or inco rrect data arrives at the
end of the loopback. The max imum 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 req u ir es s o me form of a testing device to g en er ate a cell stream. The
parameters for such a stre am are the number of cells transmitted through the lo op, 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. Thes e 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 rem ains 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 dir ec ti on of cell flow within the loop (see Figure 9-1):
•In the ingress direction, the cel ls travel from the tester to the qu eu ei ng e ngine on the AXSM; then
back to the tester.
•In the egress direction, the cell s travel from the tester to the l oc al A XS M ; th en a c ros s th e n etwork
to the remote AXSM. At the far end, t he cells go to the queueing engine t hen return back across the
network to the tester.
The maximum number of loopbacks that can exist on an AXSM is 256.
Figure9-1 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 1AXSM
Tester Egress: mode 2AXSM 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 r an g e i s 0 –4095.