Re: Frame-relay VAF and VATS not kicking it

From: Petr Lapukhov <petr_at_internetworkexpert.com>
Date: Sat, 9 Jan 2010 16:00:58 -0800

Hi,

As far as VAF and VATS are concerned, the features are not very
"deterministic" or stable. The reason for this seems to be connected
to MQC-based FRTS, which I found to sometimes behave strangely too.
This might vary from one IOS version to another, but personally I had
to reload a router in order to get VAF/VATS working. You seem to be
referring to the example from our IEWB-RS VOL1 QoS sections, and this
is exactly the case that caused me troubles when I was testing it.

In real life, I would probably opt to go with legacy FRTS or
class-based traffic shaping and classic fragmentation. Although VATS
seems attractive on oversubscribed connections, it does not seem to be
a reliable feature :) As for the exam, the verification procedure will
most likely check your setting using the "show" commands and will not
simulate any real traffic flows to check for fragmented/delayed
packets.

HTH

-- 
Petr Lapukhov, petr_at_INE.com
CCIE #16379 (R&S/Security/SP/Voice)
Internetwork Expert, Inc.
http://www.INE.com
Toll Free: 877-224-8987
Outside US: 775-826-4344
2010/1/9 Jorge Cortes <jorge.cortes.cano_at_gmail.com>:
> Thanks for looking into this email. Here are my comments:
>
> 1. "frame-relay traffic-shaping" is not needed when  using MQC FRTS
> 2. I am not using shape peak and shape average for the same class,
> those are mutually exclusive just as you said. I am using shape peak
> with shape adaptive so the shaper BW is reduced from PIR to CIR should
> any packets are in the LLQ
>
> On the other hand I tried this again first thing in the morning
> without doing any changes (maybe the rack was reloaded in the night,
> or my configs were loaded to a whole new rack, but I didn't change
> anything) and it worked nicely. This really concerns me since this is
> the second time something like this happens to me (last time it was an
> issue with multicast though) where something is not working and when I
> try the next day everything works fine, which makes think the issues
> are fixed with a reboot. What are the chances of this happening at the
> exam?
>
> Thanks again,
>
> Jorge
>
> On Sat, Jan 9, 2010 at 1:50 PM, Derrick Kea <dekea_at_cisco.com> wrote:
>> Hi Jorge,
>>
>> I think you just need to turn on frame-relay traffic-shaping on the
>> interface.
>>
>> int s0/0/0
>> frame-relay traffic-shaping
>>
>>
>> Best,
>>
>> Derrick
>>
>>
>>
>>
>> On 1/8/10 7:25 PM, "Jorge Cortes" <jorge.cortes.cano_at_gmail.com> wrote:
>>
>>> Hi Team,
>>>
>>> I am not able to get VAF and VATS to work properly. Both show as
>>> inactive even when there are packets in the LLQ. I don't know what I
>>> am doing wrong, so I would appreciate any help with this issue.
>>>
>>> This is the output of command "show frame-relay pvc 305"
>>>
>>> Rack1R5#sh frame-relay pvc 503
>>>
>>> PVC Statistics for interface Serial0/0/0 (Frame Relay DTE)
>>>
>>> DLCI = 503, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/0/0
>>>
>>>   input pkts 10882         output pkts 10403        in bytes 897945
>>>   out bytes 2068873        dropped pkts 0           in pkts dropped 0
>>>   out pkts dropped 0                out bytes dropped 0
>>>   in FECN pkts 0           in BECN pkts 0           out FECN pkts 0
>>>   out BECN pkts 0          in DE pkts 0             out DE pkts 0
>>>   out bcast pkts 270       out bcast bytes 125360
>>>   5 minute input rate 12000 bits/sec, 24 packets/sec
>>>   5 minute output rate 13000 bits/sec, 24 packets/sec
>>>   pvc create time 02:22:58, last time pvc status changed 00:12:02
>>>   fragment type end-to-end fragment size 480 adaptive inactive
>>> =======================> VAF is configured but inactive
>>>   service policy DLCI503
>>>  Serial0/0/0: DLCI 503 -
>>>
>>>   Service-policy output: DLCI503
>>>
>>>     Class-map: class-default (match-any)
>>>       5206 packets, 395428 bytes
>>>       30 second offered rate 13000 bps, drop rate 0 bps
>>>       Match: any
>>>       Traffic Shaping
>>>            Target/Average   Byte   Sustain   Excess    Interval  Increment
>>>              Rate           Limit  bits/int  bits/int  (ms)      (bytes)
>>>             56000/32000     1400   6400      4800      200       1400
>>>
>>>         Adapt  Queue     Packets   Bytes     Packets   Bytes     Shaping
>>>         Active Depth                         Delayed   Delayed   Active
>>>         BECN   0         0         0         0         0         no
>>>         Voice Adaptive Shaping inactive
>>> ======================================>VATS is configured but inactive
>>>
>>>       Service-policy : VOICE
>>>
>>>         Class-map: VOICE (match-all)
>>>           5049 packets, 323136 bytes
>>>           30 second offered rate 12000 bps, drop rate 0 bps
>>> ===========================> There is traffic in the LLQ
>>>           Match:  dscp ef (46)
>>>           Queueing
>>>             Strict Priority
>>>             Output Queue: Conversation 24
>>>             Bandwidth 32 (kbps) Burst 800 (Bytes)
>>>             (pkts matched/bytes matched) 0/0
>>>             (total drops/bytes drops) 0/0
>>>
>>>         Class-map: class-default (match-any)
>>>           157 packets, 72292 bytes
>>>           30 second offered rate 0 bps, drop rate 0 bps
>>>           Match: any
>>>   Output queue size 0/max total 600/drops 0
>>>
>>>
>>> These are the relevant configurations:
>>>
>>> interface Serial0/0/0
>>>  ip address 155.1.0.5 255.255.255.0
>>>  ip rip advertise 10
>>>  encapsulation frame-relay
>>>  load-interval 30
>>>  frame-relay fragmentation voice-adaptive deactivation 30
>>>  frame-relay map ip 155.1.0.1 501 broadcast
>>>  frame-relay map ip 155.1.0.2 502 broadcast
>>>  frame-relay map ip 155.1.0.3 503 broadcast
>>>  frame-relay map ip 155.1.0.4 504 broadcast
>>>  frame-relay interface-dlci 502
>>>   class DLC502
>>>  frame-relay interface-dlci 503
>>>   class DLC503
>>>  no frame-relay inverse-arp
>>>
>>> map-class frame-relay DLC502
>>>  frame-relay fragment 480
>>>  service-policy output DLCI502
>>>
>>> map-class frame-relay DLC503
>>>  frame-relay fragment 480
>>>  service-policy output DLCI503
>>>
>>> policy-map DLCI503
>>>  class class-default
>>>   shape peak 32000 6400 4800
>>>   shape adaptive 32000
>>>   shape fr-voice-adapt deactivation 30
>>>   service-policy VOICE
>>>
>>> policy-map DLCI502
>>>  class class-default
>>>   shape peak 256000 12800 12800
>>>   shape adaptive 256000
>>>   shape fr-voice-adapt deactivation 30
>>>   set fr-de
>>>   service-policy VOICE
>>>
>>> policy-map VOICE
>>>  class VOICE
>>>   priority 32
>>>
>>>
>>> Thanks,
>>>
>>> Jorge
>>>
>>>
>>> Blogs and organic groups at http://www.ccie.net
>>>
>>> _______________________________________________________________________
>>> Subscription information may be found at:
>>> http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
Blogs and organic groups at http://www.ccie.net
Received on Sat Jan 09 2010 - 16:00:58 ART

This archive was generated by hypermail 2.2.0 : Thu Feb 04 2010 - 20:28:41 ART