Understanding QoS

Studying QoS and playing
with it ... quick dummy questions ..

Ok, I have
this policy

!

policy-map
QoS_Output_Policy

 class VoIP

  priority
percent
35

  set ip dscp ef

 class Video

  priority percent
25

  set ip
dscp af41

 class SIP

  bandwidth
remaining percent 25

  set ip dscp af31
class Data

  bandwidth
remaining percent 15

  set ip dscp af21

 class
class-default

  fair-queue

  set dscp default

!

!

interface
GigabitEthernet0/2

 duplex full

 speed 100

 service-policy
output
QoS_Output_Policy

!

* Is by default 75%
(75MB) of 1 GB bandwidth is
available for use?

* I can't apply
"max-reserved-bandwidth" to a gig
interface. How can I use the total
1GB bandwidth?

* "priority percent
35"
means LLQ and VoIP class gets 26MB (75MB * 35%)?

* "bandwidth
remaining
percent 25" SIP traffic gets 12MB (75MB - 26MB = 46MB * 25% =
12MB)?

* How
can I verify it
there is indeed a congestion happened?

DC1-3FL-RTR001#sh
policy-map int g0/2

 GigabitEthernet0/2

  Service-policy
output:
QoS_Output_Policy

    queue stats
for all priority classes:
Queueing

     
queue limit 64 packets

     
(queue depth/total
drops/no-buffer drops) 0/0/0

     
(pkts output/bytes output)
60579572/8599620493

    Class-map:
VoIP (match-any)

     
58813111
packets, 8056468225 bytes

      5
minute offered rate 0000 bps, drop rate
0000 bps

     
Match: ip dscp ef (46)

     
  1167959 packets, 86399962
bytes

     
  5 minute rate 0 bps

     
Match: protocol rtp audio
57632956 packets, 7968100335 bytes

     
  5 minute rate 0 bps

     
Match:
protocol rtcp

     
  12196 packets, 1967928 bytes

     
  5 minute rate 0
bps

     
Priority: 35% (35000 kbps), burst bytes 875000, b/w exceed drops: 0
QoS
Set

     
  dscp ef

     
    Packets marked 58813111

    Class-map:
Video (match-any)

     
1766463 packets, 543152268 bytes

      5
minute
offered rate 0000 bps, drop rate 0000 bps

     
Match: ip dscp af41 (34)
1653227 packets, 526896986 bytes

     
  5 minute rate 0 bps

     
Match:
protocol rtp video

     
  0 packets, 0 bytes

     
  5 minute rate 0 bps
Match: protocol video-over-http

     
  0 packets, 0 bytes

     
  5 minute
rate 0 bps

     
Match: access-group name video

     
  113236 packets,
16255282 bytes

     
  5 minute rate 0 bps

     
Priority: 25% (25000 kbps),
burst bytes 625000, b/w exceed drops: 0

      QoS
Set

     
  dscp af41
Packets marked 1766463

    Class-map:
SIP (match-any)

     
1125626
packets, 314867881 bytes

      5
minute offered rate 6000 bps, drop rate 0000
bps

     
Match: ip dscp af31 (26)

     
  572572 packets, 98559349 bytes
5 minute rate 3000 bps

     
Match: protocol sip

     
  553043 packets,
216307750 bytes

     
  5 minute rate 3000 bps

     
Match: ip dscp cs3 (24)
af31 (26)

     
  11 packets, 782 bytes

     
  5 minute rate 0 bps
Queueing

     
queue limit 64 packets

     
(queue depth/total
drops/no-buffer drops) 0/0/0

     
(pkts output/bytes output)
1125626/314867881

     
bandwidth remaining 25%

      QoS
Set

     
  dscp
af31

     
    Packets marked 1125626

    Class-map:
Data (match-any)
0
packets, 0 bytes

      5
minute offered rate 0000 bps, drop rate 0000 bps
Match: ip dscp af21 (18)

     
  0 packets, 0 bytes

     
  5 minute rate 0
bps

     
Queueing

     
queue limit 64 packets

     
(queue depth/total
drops/no-buffer drops) 0/0/0

     
(pkts output/bytes output) 0/0
bandwidth remaining 15%

      QoS
Set

     
  dscp af21

     
    Packets
marked 0

    Class-map:
class-default (match-any)

     
791611850
packets, 912546925544 bytes

      5
minute offered rate 16514000 bps, drop
rate 0000 bps

     
Match: any

     
Queueing

     
queue limit 64 packets
(queue depth/total drops/no-buffer drops/flowdrops) 0/5/0/5

     
(pkts
output/bytes output) 791611623/912502991512

     
Fair-queue: per-flow queue
limit 16 packets

      QoS
Set

     
  dscp default

     
    Packets
marked 791481954

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Received on Thu Jun 27 2013 - 16:47:26 ART