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New Member

Cisco 2960 and iptv (total output drops)

Hello everyone ,

We are using IPTV system and we have 4500 backbone and 2960 switches.

Sometimes I have packet losses, When I check it I saw that I have a lot of total output drops !

FastEthernet0/38 is up, line protocol is up (connected)

  Hardware is Fast Ethernet, address is 0018.73e9.eaa6 (bia 0018.73e9.eaa6)

  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,

     reliability 255/255, txload 16/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Full-duplex, 100Mb/s, media type is 10/100BaseTX

  input flow-control is off, output flow-control is unsupported

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input never, output 00:00:01, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 103262784

  Queueing strategy: fifo

  Output queue: 0/40 (size/max)

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 6562000 bits/sec, 609 packets/sec

     171553 packets input, 17987504 bytes, 0 no buffer

     Received 2210 broadcasts (1895 multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 1895 multicast, 0 pause input

     0 input packets with dribble condition detected

     82119787 packets output, 95934553563 bytes, 0 underruns

     5 output errors, 0 collisions, 1 interface resets

     0 unknown protocol drops

     0 babbles, 0 late collision, 0 deferred

     0 lost carrier, 0 no carrier, 0 pause output

     0 output buffer failures, 0 output buffers swapped out

Interface Fa0/38 TxQueue Drop Statistics

  Queue 0

    Weight 0 Frames 0

    Weight 1 Frames 0

    Weight 2 Frames 0

  Queue 1

    Weight 0 Frames 0

    Weight 1 Frames 0

    Weight 2 Frames 0

  Queue 2

    Weight 0 Frames 0

    Weight 1 Frames 0

    Weight 2 Frames 103914952

  Queue 3

    Weight 0 Frames 0

    Weight 1 Frames 0

    Weight 2 Frames 0

I have used this qos settings

mls qos map cos-dscp 0 8 16 24 34 46 48 56

mls qos srr-queue input bandwidth 9 1

mls qos srr-queue input threshold 1 90 100

mls qos srr-queue input threshold 2 90 95

mls qos srr-queue input buffers 95 5

mls qos srr-queue input priority-queue 2 bandwidth 5

mls qos srr-queue input cos-map queue 1 threshold 3 0 2 3 4

mls qos srr-queue input cos-map queue 2 threshold 2 5

mls qos srr-queue input cos-map queue 2 threshold 3 6 7

mls qos srr-queue input dscp-map queue 1 threshold 3 0 1 2 3 4 5 6 7

mls qos srr-queue input dscp-map queue 1 threshold 3 16 17 18 19 20 21 22 23

mls qos srr-queue input dscp-map queue 1 threshold 3 24 25 26 27 28 29 30 31

mls qos srr-queue input dscp-map queue 1 threshold 3 32 33 34 35 36 37 38 39

mls qos srr-queue input dscp-map queue 2 threshold 2 40 41 42 43 44 45 46 47

mls qos srr-queue input dscp-map queue 2 threshold 3 48 49 50 51 52 53 54 55

mls qos srr-queue input dscp-map queue 2 threshold 3 56 57 58 59 60 61 62 63

mls qos srr-queue output cos-map queue 1 threshold 3 5

mls qos srr-queue output cos-map queue 2 threshold 1 2 4

mls qos srr-queue output cos-map queue 2 threshold 2 3

mls qos srr-queue output cos-map queue 2 threshold 3 6 7

mls qos srr-queue output cos-map queue 3 threshold 3 0

mls qos srr-queue output cos-map queue 4 threshold 3 1

mls qos srr-queue output dscp-map queue 1 threshold 3 46

mls qos srr-queue output dscp-map queue 2 threshold 1 16 18 20 22 25 32 34 36

mls qos srr-queue output dscp-map queue 2 threshold 1 38

mls qos srr-queue output dscp-map queue 2 threshold 2 24 26

mls qos srr-queue output dscp-map queue 2 threshold 3 48 56

mls qos srr-queue output dscp-map queue 3 threshold 3 0

mls qos srr-queue output dscp-map queue 4 threshold 1 8

mls qos srr-queue output dscp-map queue 4 threshold 3 10 12 14

mls qos queue-set output 1 threshold 1 3100 3100 100 3200

mls qos queue-set output 1 threshold 2 70 80 100 100

mls qos queue-set output 1 threshold 3 3100 3100 100 3200

mls qos queue-set output 1 threshold 4 40 100 100 100

mls qos queue-set output 1 buffers 10 20 10 60

mls qos

interface FastEthernet0/38

switchport access vlan 20

switchport mode access

srr-queue bandwidth share 10 20 10 60

srr-queue bandwidth shape 0 0 0 0

queue-set 2

priority-queue out

mls qos trust dscp

spanning-tree portfast

spanning-tree bpduguard enable

!

  • LAN Switching and Routing
5 REPLIES
Super Bronze

Re: Cisco 2960 and iptv (total output drops)

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Sometimes I have packet losses, When I check it I saw that I have a lot of total output drops !

Yes, I would agree with your statement.

Did you have a question? 

PS:

You might want to read: https://supportforums.cisco.com/docs/DOC-8093 (2960s are similar)

New Member

Cisco 2960 and iptv (total output drops)

Yes !

Where I am doing mistake ! Could you help me about this subject !

I tried a lot of configuration and read a lot of document ! But I could not stop this total output drops  !

Could you send me a config file or tell me how could i solve this problem ?

Super Bronze

Re: Cisco 2960 and iptv (total output drops)

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

Could you send me a config file or tell me how could i solve this problem ?


Solving this kind of situation, will likely require some trial and error with the device's QoS settings.

In principle, and assuming drops are due to transient bursts, you need to provide additional buffer resources for the traffic that's being dropped.

This can require some complex "juggling" of QoS settings, as, for example, you may deprive other traffic of their buffer resources.

Ideally, you can take buffers resources from traffic that doesn't really need those buffer resources and provide those buffer resources to the traffic that does.

One size doesn't fit all.  So, I can't easily provide you a config file that will solve your problem.

If the complexity of this is beyond you (no shame in that - it can be surprising complex to get it "right"), you may want to buy some consulting time of a QoS expert.

As alternative, you might try just disabling QoS.

New Member

Cisco 2960 and iptv (total output drops)

I just want to see example of qos settings, if who using iptv with cisco 2960 switches...

I have packet losses if im disable qos too.

Super Bronze

Re: Cisco 2960 and iptv (total output drops)

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

 

The document reference I provided in my first posting has examples, although I don't know of any samples for IPTV in particular.  You might find something if you search Cisco's main site for QoS for streaming video (on devices other than 2960).

If you get drops with QoS disabled, either you have continuous oversubscription, which mean you need more bandwidth.  Or, you have a case of serious transient congestion where you need a device that has deeper buffers, such as the 4900 series.  (A 3650 series "uplink" port may offer deeper buffers too.)  Or you need to allow, possibly even more, drops against other traffic.  The latter, if there's some other less critical sharing the port with your IPTV traffic.

It's been a while since I've worked with IPTV.  Is it possible to encode your video streams so that they use less bandwidth?  I realize quality and/or screen size may be reduced, but too many drops on the traffic isn't good for its quality either.

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