From: mihai (mihai@ngnpath.com)
Date: Thu May 31 2007 - 08:14:31 ART
Thank you very much for your time!!!
I missed the tx ring issue and I was under the impression that no matter
what, everything else stops once there is a priority command, nothing
else gets through to the tx ring (i used 1000 - 5000 pings to make sure
everything else which was on the tx ring before gets transmitted and
after that if I stay below the bandwidth specified in priority command
then only my icmp will be put on the tx ring)
I'll test your idea, thank you again.
Gavin Lawson wrote:
> Hi mihai
>
> The reason for this is the Hardware Queues.
> When ever you apply the software queue's (i.e the LLQ) the router will
> shorten the hardware queue to 2 packets.
> This hardware queue will act in a FIFO fashion.
>
> Since your background traffic is using 1500 byte packets (12000 bits)
> there will most likely be 2 of these packets in the hardware queue in
> front of each "priority icmp" packet.
> To put the 2 1500 byte packets on the line, it will take about 360 ms,
> then your "priority icmp" packet will be put on the line.
> The same will apply in the reverse direction. i.e another 360 ms - then
> your "priority icmp" packet.
> All up about 720ms :-)
> All this even though the priority queue is configured for the interface.
>
> The way you would alleviate this delay in a voice network would be to
> use LFI (Link fragmentation and Interleaving)
> The protocols to do LFI, is either Frame Relay or Multilink PPP.
>
> I hope this helps.
>
> GL
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> mihai
> Sent: Thursday, 31 May 2007 8:58 AM
> To: ccielab@groupstudy.com
> Subject: Re: QoS test
>
> Going further I added two more routers R1 - R5 - R3 - R6 - R4 Traffic
> generator on R5, test ping from R1 to R4, link between R3 and R6 100%
> usage.
>
> Just plain and simple priority command for icmp traffic and I would like
> to see same RTT time from ping with that serial link flooded.
>
> Is this how u guys would practice QoS commands?
> Bandwidth command seems to be working ... shape average command seems to
> be working ... I got stuck with this priority :))
>
> I mean all it looks nice in the workbooks but I would like to see it
> working live on my 26xx routers.
>
> Let me know even if this question of mine is the most stupid question
> asked :))) ... I'll take the heat!
>
> Thx for your time,
>
> Mihai
>
>
>
>
> mihai wrote:
>> Here is what I can see on R3 and is similar to all the routers
>> involved in this small test.
>>
>> r3#sh access-lists
>> Extended IP access list 100
>> 10 permit icmp any any echo (65 matches)
>> 20 permit icmp any any echo-reply (40 matches) r3#
>>
>> Before flooding the s1/3:
>>
>> r5#ping 6.6.6.6
>>
>> Type escape sequence to abort.
>> Sending 5, 100-byte ICMP Echos to 6.6.6.6, timeout is 2 seconds:
>> !!!!!
>> Success rate is 100 percent (5/5), round-trip min/avg/max = 28/31/32
>> ms r5#
>>
>> Flooding started:
>>
>> r3#sh int s1/3
>> Serial1/3 is up, line protocol is up
>> Hardware is CD2430 in sync mode
>> Internet address is 155.1.36.3/24
>> MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
>> reliability 255/255, txload 255/255, rxload 239/255
>> Encapsulation HDLC, loopback not set
>> Keepalive set (10 sec)
>> Last input 00:00:00, output 00:00:00, output hang never
>> Last clearing of "show interface" counters 00:01:26
>> Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops:
> 0
>> Queueing strategy: Class-based queueing
>> Output queue: 7/1000/64/0 (size/max total/threshold/drops)
>> Conversations 3/8/16 (active/max active/max total)
>> Reserved Conversations 0/0 (allocated/max allocated)
>> Available Bandwidth 28 kilobits/sec
>> 30 second input rate 60000 bits/sec, 15 packets/sec
>> 30 second output rate 64000 bits/sec, 16 packets/sec
>> 1288 packets input, 661412 bytes, 0 no buffer
>> Received 11 broadcasts, 0 runts, 0 giants, 0 throttles
>> 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
>> 1406 packets output, 696106 bytes, 0 underruns
>> 0 output errors, 0 collisions, 0 interface resets
>> 0 output buffer failures, 0 output buffers swapped out
>> 0 carrier transitions
>> DCD=up DSR=up DTR=up RTS=up CTS=up r3#
>>
>>
>> r3#sh policy-map int s1/3
>> Serial1/3
>>
>> Service-policy output: p-icmp
>>
>> Class-map: icmp (match-all)
>> 59 packets, 6136 bytes
>> 30 second offered rate 2000 bps, drop rate 0 bps
>> Match: access-group 100
>> Queueing
>> Strict Priority
>> Output Queue: Conversation 24
>> Bandwidth 20 (kbps) Burst 500 (Bytes)
>> (pkts matched/bytes matched) 59/6136
>> (total drops/bytes drops) 0/0
>>
>> Class-map: class-default (match-any)
>> 3040 packets, 1510159 bytes
>> 30 second offered rate 69000 bps, drop rate 3000 bps
>> Match: any
>> r3#sh policy-map int s1/3
>> Serial1/3
>>
>> Service-policy output: p-icmp
>>
>> Class-map: icmp (match-all)
>> 74 packets, 7696 bytes
>> 30 second offered rate 2000 bps, drop rate 0 bps
>> Match: access-group 100
>> Queueing
>> Strict Priority
>> Output Queue: Conversation 24
>> Bandwidth 20 (kbps) Burst 500 (Bytes)
>> (pkts matched/bytes matched) 74/7696
>> (total drops/bytes drops) 0/0
>>
>> Class-map: class-default (match-any)
>> 3098 packets, 1539943 bytes
>> 30 second offered rate 69000 bps, drop rate 3000 bps
>> Match: any
>> r3#
>>
>> r3#sh access-lists
>> Extended IP access list 100
>> 10 permit icmp any any echo (185 matches)
>> 20 permit icmp any any echo-reply (175 matches) r3#
>>
>>
>> Tarun Pahuja wrote:
>>> Mihai,
>>> What does the show output of Policy-Map say, do you see any
>
>>> packets being matched and being put in the prority queue?
>>>
>>> Thanks,
>>> Tarun
>>>
>>>
>>>
>>>
>>> On 5/29/07, mihai <mihai@ngnpath.com> wrote:
>>>> Hi all,
>>>>
>>>> Not sure what's going on ...
>>>> Here is what I have:
>>>>
>>>> R5 --Eth--R3--Serial with clock rate 64k--R6
>>>>
>>>> IP connectivity ok and ping from R5 to R6 ~ 6x ms Start rtr on R5 to
>
>>>> bring the serial between R3 and R6 to 100% usage.
>>>> Ping from R5 to R6 ~ 800 ms
>>>>
>>>> I would like to test priority command with MQC for ping traffic
>>>> (icmp) My expectation is to get RTT around 6x ms with priority
>>>> command in place.
>>>>
>>>> This is not happening ... and I can't figure out what I'm doing
> wrong.
>>>> MQC related config:
>>>>
>>>> class-map match-all t1
>>>> match access-group 100
>>>> !
>>>> policy-map p-t1
>>>> class t1
>>>> priority 16
>>>>
>>>> access-list 100 permit icmp any any echo access-list 100 permit icmp
>
>>>> any any echo-reply
>>>>
>>>> Service policy output p-t1 on R5,R3 and R6.
>>>>
>>>> Any idea what's wrong with this test of mine?
>>>> Thx.
>>>>
>>>> Mihai
>>>>
>>>> ____________________________________________________________________
>>>> ___ Subscription information may be found at:
>>>> http://www.groupstudy.com/list/CCIELab.html
>>> _____________________________________________________________________
>>> __ Subscription information may be found at:
>>> http://www.groupstudy.com/list/CCIELab.html
>> ______________________________________________________________________
>> _ Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Fri Jun 01 2007 - 06:55:23 ART