From: Kenneth Wygand (KWygand@customonline.com)
Date: Mon May 03 2004 - 10:26:00 GMT-3
Bob,
Couldn't agree with you more about having to just do it and find things out for ourselves. Thanks for your efforts!
(By the way, I also check Cisco's DQOS book without a definitive result...)
Thanks!
Ken
-----Original Message-----
From: Bob Sinclair [mailto:bsinclair@netmasterclass.net]
Sent: Mon 5/3/2004 9:21 AM
To: Kenneth Wygand; Devi Mallampalli; GAD; ccielab@groupstudy.com
Cc:
Subject: Re: CBWFQ Question
Kenneth,
Yes, I saw that in the config guide. I also checked the Cisco DQOS and
Vegesna books, without getting a definitive answer. I did find the
following quote
quote:
If the user does not configure a default class, packets are still treated as
members of the default class. However, by default, the default class has no
enabled features. Therefore, packets belonging to a default class with no
configured features have no QoS functionality. These packets are then placed
into a FIFO queue and forwarded at a rate determined by the available
underlying link bandwidth. This FIFO queue is managed by tail drop.
end quote
This is from the modular QoS config guide at this link:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/fqcprt8/qcfmcli2.htm
Played with this last night, and it really seems like you only get
flow-based WFQ within the class-default if you enter the fair-queue command
on the class-default.
It certainly is challenging when you find different statements in different
parts of the docs. It may be that there have been changes over the IOS
versions, or it may be that the docs (one or the other) is wrong, or it may
be that I am misinterpreting them. In the end, I think we need to go to the
IOS itself and use the show and debug to figure this out.
Thanks,
Bob Sinclair
CCIE #10427, CISSP, MCSE
www.netmasterclass.net
----- Original Message -----
From: "Kenneth Wygand" <KWygand@customonline.com>
To: "Devi Mallampalli" <Devi.Mallampalli@chubb.com.au>; "Bob Sinclair"
<bsin@cox.net>; "GAD" <gad@gad.net>; <ccielab@groupstudy.com>
Sent: Monday, May 03, 2004 9:00 AM
Subject: RE: CBWFQ Question
> Devi,
>
> I understand what you are saying, however according to the Cisco
documentation Gad and myself found, the default queueing for the
class-default class is _not_ FIFO, but flow-based WFQ. It also explicitly
states that when you configure a defined amount of bandwidth for any
particular class (class-default included), this does _not_ support
flow-based WFQ, rather FIFO is the only queueing mechanism Cisco supports
when issuing the "bandwidth" command.
>
> <snip>
> If no default class is configured, then by default the traffic that does
not match any of the configured classes is flow classified and given
best-effort treatment.
> By default, the class-default class is defined as flow-based WFQ. However,
configuring the default class with the bandwidth policy-map class
configuration command disqualifies the default class as flow-based WFQ.
> </snip>
>
>
http://www.cisco.com/en/US/products/sw/iosswrel/ps1830/products_feature_guide09186a0080087a84.html#25297
>
> Any thoughts?
> Ken
>
> -----Original Message-----
> From: nobody@groupstudy.com on behalf of Devi Mallampalli
> Sent: Mon 5/3/2004 8:46 AM
> To: Bob Sinclair; GAD; ccielab@groupstudy.com
> Cc:
> Subject: RE: CBWFQ Question
>
>
>
> Hi GAD,
>
> I agree with Bob, the class of class-default will use "FIFO" as its
> default queuing mechanism. My understanding of CBWFQ's policy maps, even
> though class class-default will be activated as soon as you create a
> policy map for each kind of traffic as I have done at below example ,
> the default nature ( FIFO) will not be altered until , you "set" the
> condition with either "DSCP"/Ip precedence value or even "bandwidth
> command value".
>
> In other words, where I have defined "fair-queue" on class-default of
> WAN-EDGE-DATA policy, the queuing for all NON matching traffic other
> than "Class DATA" will be put under "class-default" and assign a flow
> based fair queue". And on the other hand , if I do not "set" the
> condition, under class-default, the default of "FIFO" will kick in.
>
> I tend to always define certain "set" condition under class-default of
> each "policy-map" with in CBWFQ so that "no single session or user can
> dominate the "wire" which can happen with in default "FIFO".
>
> Also please note that when you enable FRTS on serial interface , she
> will automatically "disable" the "fair queue" on the interface. So it is
> always a good idea to deploy some kind of congestion management queuing
> technique ( ex :CBWFQ , CQ ..etc)so that you are not allowing any single
> conversation on the link to consume the majority of the B/W.
>
> policy-map WAN-EDGE-VOICE
> class VOIP-RTP
> priority 70
> class VOIP-SIG
> bandwidth 8
> class class-default
> bandwidth 40
> policy-map WAN-EDGE-DATA
> class DATA
> priority 400
> class class-default
> fair-queue >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> random-detect
> policy-map LAN-EDGE
> class VOIP-RTP
> set cos 5
> class VOIP-SIG
> set cos 3
> class class-default >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>
> Router# sh frame pvc <dlci>
>
> PVC Statistics for interface Serial0/0 (Frame Relay DTE)
>
> DLCI = 200, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =
> Serial0/0.200
>
> input pkts 220815371 output pkts 260090287 in bytes 4092929658
> out bytes 1169002120 dropped pkts 114 in pkts dropped 0
> out pkts dropped 290002 out bytes dropped 432641264
> late-dropped out pkts 290002 late-dropped out bytes 432641264
> in FECN pkts 30 in BECN pkts 5 out FECN pkts 0
> out BECN pkts 0 in DE pkts 83264630 out DE pkts 0
> out bcast pkts 625444 out bcast bytes 50327356
> pvc create time 25w4d, last time pvc status changed 2w1d
> cir 1792000 bc 1792000 be 0 byte limit 7168 interval 32
> mincir 1792000 byte increment 7168 Adaptive Shaping none
> pkts 260090184 bytes 1168895936 pkts delayed 151016040 bytes delayed
> 243187049
>
> shaping active
> traffic shaping drops 289888
> service policy WAN-EDGE-DATA
> Serial0/0.200: DLCI 200 -
>
> Service-policy output: WAN-EDGE-DATA
>
> Class-map: DATA (match-any)
> 17897677 packets, 818527532 bytes
> 30 second offered rate 0 bps, drop rate 0 bps
> Match: access-group name ACL-DATA-TELNET
> 17897635 packets, 818521832 bytes
> 30 second rate 0 bps
> Match: protocol telnet
> 40 packets, 5612 bytes
> 30 second rate 0 bps
> Queueing
> Strict Priority
> Output Queue: Conversation 72
> Bandwidth 400 (kbps) Burst 10000 (Bytes)
> (pkts matched/bytes matched) 681512/30904515
> (total drops/bytes drops) 0/0
>
> Class-map: class-default (match-any)
> 202495162 packets, 174811720189 bytes
> 30 second offered rate 1791000 bps, drop rate 2000 bps
> Match: any
> Queueing
> Flow Based Fair Queueing
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> Maximum Number of Hashed Queues 64
> (total queued/total drops/no-buffer drops) 23/277209/0
> exponential weight: 9
>
>
>
>
>
> -----Original Message-----
> From: Bob Sinclair [mailto:bsin@cox.net]
> Sent: Monday, 3 May 2004 10:40 AM
> To: GAD; ccielab@groupstudy.com
> Subject: Re: CBWFQ Question
>
>
> Gad,
>
> Class-default can use FIFO or WFQ. I believe FIFO is the default.
>
> HTH,
>
> Bob Sinclair
> CCIE #10427, CISSP, MCSE
> www.netmasterclass.net
>
> ----- Original Message -----
> From: "GAD" <gad@gad.net>
> To: <ccielab@groupstudy.com>
> Sent: Sunday, May 02, 2004 8:13 PM
> Subject: CBWFQ Question
>
>
> > Question. If you do not specify the "class-default" class in a
> > policy-map, the class-default class appears, but it does not say
> > "Weighted fair queueing". Can someone tell me what it IS doing?
> >
> > ex:
> >
> > class-map match-all Prec-5
> > match ip precedence 5
> >
> > policy-map GAD
> > class Prec-5
> > bandwidth percent 90
> >
> > int s0
> > service-policy outbound GAD
> >
> > R3#sho policy-map interface s0
> >
> > Serial0
> >
> > Service-policy output: GAD
> >
> > Class-map: Telnet (match-all)
> > 0 packets, 0 bytes
> > 5 minute offered rate 0 bps, drop rate 0 bps
> > Match: ip precedence 5
> > Weighted Fair Queueing
> > Output Queue: Conversation 265
> > Bandwidth 90 (%) Max Threshold 64 (packets)
> > (pkts matched/bytes matched) 0/0
> > (depth/total drops/no-buffer drops) 0/0/0
> >
> > Class-map: class-default (match-any)
> > 1 packets, 13 bytes
> > 5 minute offered rate 0 bps, drop rate 0 bps
> > Match: any
> >
> > Difference when you add:
> >
> > class class-default
> > bandwidth percent 10
> >
> > To the policy map is:
> >
> > R3#sho policy-map interface s0
> >
> > Serial0
> >
> > Service-policy output: GAD
> >
> > Class-map: Telnet (match-all)
> > 0 packets, 0 bytes
> > 5 minute offered rate 0 bps, drop rate 0 bps
> > Match: ip precedence 5
> > Weighted Fair Queueing
> > Output Queue: Conversation 265
> > Bandwidth 90 (%) Max Threshold 64 (packets)
> > (pkts matched/bytes matched) 0/0
> > (depth/total drops/no-buffer drops) 0/0/0
> >
> > Class-map: class-default (match-any)
> > 38 packets, 494 bytes
> > 5 minute offered rate 0 bps, drop rate 0 bps
> > Match: any
> > Weighted Fair Queueing
> > Output Queue: Conversation 266
> > Bandwidth 10 (%) Max Threshold 64 (packets)
> > (pkts matched/bytes matched) 0/0
> > (depth/total drops/no-buffer drops) 0/0/0
> >
> > Notice the addition of the last 5 lines.
> >
> > So my question is, in the first example, what is the queuing
> > mechaninsm if not WFQ? Queueing for the interface is Weighted Fair as
> > shown in in a show
> > int:
> >
> > Serial0 is up, line protocol is up
> > Hardware is HD64570
> > Internet address is 208.28.1.2/29
> > MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
> > reliability 255/255, txload 1/255, rxload 1/255
> > Encapsulation FRAME-RELAY, loopback not set
> > Keepalive set (10 sec)
> > LMI enq sent 43526, LMI stat recvd 43527, LMI upd recvd 0, DTE LMI
> up
> > LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
> > LMI DLCI 1023 LMI type is CISCO frame relay DTE
> > FR SVC disabled, LAPF state down
> > Broadcast queue 0/64, broadcasts sent/dropped 2/0, interface
> > broadcasts 0
> > Last input 00:00:04, output 00:00:04, output hang never
> > Last clearing of "show interface" counters 5d01h
> > Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops:
> 0
> > Queueing strategy: weighted fair
> > Output queue: 0/1000/64/0 (size/max total/threshold/drops)
> > Conversations 0/1/256 (active/max active/max total)
> > Reserved Conversations 2/2 (allocated/max allocated)
> > Available Bandwidth 1158 kilobits/sec
> > 5 minute input rate 0 bits/sec, 0 packets/sec
> > 5 minute output rate 0 bits/sec, 0 packets/sec
> > 50821 packets input, 2826502 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
> > 43576 packets output, 570160 bytes, 0 underruns
> > 0 output errors, 0 collisions, 3 interface resets
> > 0 output buffer failures, 0 output buffers swapped out
> > 1 carrier transitions
> > DCD=up DSR=up DTR=up RTS=up CTS=up
> >
> > I'm sure the answer is obvious somehwere, but I'm fried and it's
> > eluding me.
> >
> > Thanks!
> >
> > GAD
> >
> > ______________________________________________________________________
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