[c-nsp] Pause Output on interface...

[Jonathan Charles]

We have a Cisco 2921 running 15.2(3T);

We are seeing PAUSE OUTPUT incrementing on the device, and every time it
does, our users experience pretty nasty jitter and silence on VOIP calls.

The link is 1000BaseLX with a 100MB committed rate; we rarely see more than
10-15MB of output or input traffic on the interface.

Two questions:

1 - Who is originating the Pause Outputs? Cisco documentation is silent on
the subject and TAC has given us conflicting answers.
2 - If generated locally, how can we stop them from doing so? The provider
is saying these are causing the issues we are experiencing.


ROUTER#sh int gi0/1
GigabitEthernet0/1 is up, line protocol is up
  Hardware is CN Gigabit Ethernet, address is 2894.0fbd.0091 (bia
2894.0fbd.0091)
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 13/255, rxload 17/255
  Encapsulation 802.1Q Virtual LAN, Vlan ID  1., loopback not set
  Keepalive set (10 sec)
  Full Duplex, 1Gbps, media type is LX
  output flow-control is XON, input flow-control is XON
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 16:53:34
  Input queue: 1/4096/0/1204 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: Class-based queueing
  Output queue: 0/1000/0 (size/max total/drops)
  30 second input rate 6684000 bits/sec, 3871 packets/sec
  30 second output rate 5105000 bits/sec, 2906 packets/sec
     87183773 packets input, 3179860385 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     60076680 packets output, 4290590647 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 1252219 pause output
     0 output buffer failures, 0 output buffers swapped out
ROUTER#

Thanks!



Jonathan