Troubleshooting Using Frame Relay Congestion Control
Now let’s say all your users are whining that their Frame Relay connection to the corporate
site is super slow. Because you strongly suspect that the link is overloaded, you verify (see
Table 11.9) the Frame Relay congestion control information with the show frame-relay pvc
command and get this:
RouterA#sh frame-relay pvc
PVC Statistics for interface Serial0/0 (Frame Relay DTE)
Active Inactive Deleted Static
Local 1 0 0 0
Switched 0 0 0 0
Unused 0 0 0 0
DLCI = 100, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0
input pkts 1300 output pkts 1270 in bytes 21212000
out bytes 21802000 dropped pkts 4 in pkts dropped 147
out pkts dropped 0 out bytes dropped 0 in FECN pkts 147
in BECN pkts 192 out FECN pkts 147
out BECN pkts 259 in DE pkts 0 out DE pkts 214
out bcast pkts 0 out bcast bytes 0
pvc create time 00:00:06, last time pvc status changed 00:00:06
Pod1R1#
What you want to look for is the in BECN pkts 192 output because this is what’s telling
the local router that traffic sent to the corporate site is experiencing congestion. BECN means
that the path that a frame took to “return” to you is congested.
TABLE 1 1 . 9 Verifying your PVC
Command Meaning
show frame-relay pvc Provides you with a list of all configured PVCs and DLCI numbers. It
provides the status of each PVC connection and traffic statistics too.