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ATM Switch Router Software Configuration Guide
OL-7396-01
Chapter11 Configuring ATM Routing and PNNI
PNNI Connection Trace
Note It is not possible to initiate traces from CES interfaces.
Figure 11-2 shows an SVC transiting switches 1, 2, and 3. This could happen when NPI-1 and NPI-2 are
ATM UNI interfaces connecting the switches to routers. When a trace is initiated on this SVC from
interface I1 of SW-1, in a direction going out from the switch, then the following information is obtained
in the trace.
Note In this section, incoming refers to an interface through which the TC message enters the switch and
outgoing refers to the interface through which the TC message leaves the switch, or the
trace-destination-interface.
Figure11-2 SVC with Connection Trace Initiated from I1 on Switch 1
In Figure 11-2, the following information is obtained from the trace:
Switch 1
Outgoing Interface I1
Switch 2
Outgoing Interface I2
Switch 3
Outgoing Interface NPI-2
If the option to collect VPI or VCI information is specified for the example in Figure11-2, the following
information is obtained from the trace connection:
Switch 1
Outgoing: Interface I1
Switch 2
Incoming: VPI value on NNI-A; VCI value on NNI-A
Outgoing: Interface I2
Switch 3
Incoming: VPI value on NNI-B; VCI value on NNI-B
Outgoing: VPI value on NPI-2; VCI value on NPI-2; zero port -ID for non-PNNI interface;
interface NPI-2.
If however, the trace is initiated from interface I2 on switch 2, different results are obtained, depending
on the direction in which the trace is initiated. Figure11-3 shows the same SVC as Figure 11-2, but with
the trace initiated from I2 on switch 2.
NPI-1 NPI-2
SW-1 SW-2 SW-3
I1 I2
NNI-A NNI-B
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