Throttle Bandwidth

Unanswered Question
May 6th, 2010

Hello all,

I have recently implemented a disaster recovery solution at my headquarters site. I am running an mpls network and have several branch offices connected via the mpls.

The datacenter which hosts our disaster recovery equipment has a 3Mbps circuit link to our head quarters site which also has a 3Mbps circuit as part of the mpls backbone. Once I begin to push data up to the disaster recovery site all of our other branch offices connected to our mpls network experience latency. My branch office sites have standard 1.54 Mbps circuits.

We previously had a 1.54Mbps circuit at our datacenter but that was not enough bandwidth to properly synchronize data so we upgraded it to the current 3Mbps circuit. Once the upgrade took place that is when latency began to occur.

My question then is how can I find the proper balance for bandwidth?

The software vendor of the disaster recovery solution recommended we need at least 2.6mbps to properly replicate data. Therefore we upgraded to 3Mbps. Now we have latency with our other branch offices.

When I look at the multilink for our headquarters mpls router it is showing the outbound traffic to be at 95% utiliziation. Any recommendations would be appreciated.

Multilink1 is up, line protocol is up
  Hardware is multilink group interface
  Internet address is
  MTU 1500 bytes, BW 3072 Kbit, DLY 100000 usec,
     reliability 255/255, txload 247/255, rxload 161/255
  Encapsulation PPP, LCP Open, multilink Open
  Listen: CDPCP
  Open: IPCP, loopback not set
  Keepalive set (10 sec)
  DTR is pulsed for 2 seconds on reset
  Last input 00:00:26, output never, output hang never
  Last clearing of "show interface" counters 3w0d
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 4168243
  Queueing strategy: fifo
  Output queue: 32/40 (size/max)
  5 minute input rate 1951000 bits/sec, 735 packets/sec
  5 minute output rate 2976000 bits/sec, 604 packets/sec
     437054691 packets input, 107970992 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     477672571 packets output, 209632198 bytes, 0 underruns
     0 output errors, 0 collisions, 5 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions


I have this problem too.
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Paolo Bevilacqua Thu, 05/06/2010 - 13:31

You have too little bandwidth.

Add more, or try to alleviate the symptoms using QoS. To configure that properly, you will need to engage a reputable network professional, or certified cisco partner.


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