Re: 10G ethernet and 802.1q

Hi Pavel,

Reza's question was about the likely intention behind two sentences
apparently taken from a larger document. From those two lines you have
formed a negative opinion of the author, but I wonder if it is fair to
judge them based on two lines taken in isolation.

You have suggested that they author may have had load balancing in mind,
and I also believe that is likely. We differ in that you believe the
author was confusing protocols, whereas I do not think the text supports
that conclusion.

Paul.

Pavel Bykov wrote:
> While we could probably continue to look into more more depth and in a
> court-hearing-style technicalities, we are still speculating on what did the
> original author mean by that statement. And that would also be a point
> against that author for not being specific enough.
>
> On Mon, Apr 6, 2009 at 2:34 PM, Paul Cosgrove <paul.cosgrove_at_gmail.com>wrote:
>
>
>> Thanks Pavel, the link helps to clarify my point. MST is defined in
>> 802.1Q, and it is likely that the quote is referring to that. With that in
>> mind perhaps your judgement of the author may be a little harsh. While the
>> last amendments were made to 802.1Q in 2005, that is now four years old.
>> There are various other draft amendments which are likely to be added in
>> the next version of the standard (see 802.1Qau, 802.1Qbb etc). As network
>> usage patterns and requirements change, the standards change to support
>> them.
>>
>> I do not think it is correct to say that 802.1w replaced 802.1d. 802.1w
>> was the name of the proposed ammendment to 802.1d. 802.1d-2004 amended
>> 802.1d so that STP was removed from the spec, and RSTP replaced STP. See
>> http://www.ieee802.org/1/pages/802.1w.html
>> "This supplement to ISO/IEC 15802-3:1998 (IEEE Std 802.1D-1998) defines the
>> changes necessary to the operation of a MAC Bridge in order to provide rapid
>> reconfiguration capability."
>>
>> Proposed amendments, such as 802.1s or 802.1w, are defined separately
>> before they are incorporated into the standard and I think that is where the
>> confusion is arising here.
>>
>> Paul.
>>
>>
>>
>> Pavel Bykov wrote:
>>
>>
>>> Paul, to be extremely technical, the current state of .1Q is 802.1Q-2005,
>>> which is available here:
>>> http://standards.ieee.org/getieee802/download/802.1Q-2005.pdf and it
>>> incorporates all of the most recent amendments, including 802.1s, 802.1v,
>>> etc. And it is one of the most recent standards out there.
>>>
>>> In tech talk, I have always heard 802.1Q referring primarily to tagging
>>> mechanism and it's properties, not it's manipulation, like spanning trees,
>>> classification, management, etc.
>>>
>>>
>>> P.S.: 802.1d was not improved per se, but instead replaced by more
>>> advanced
>>> 802.1w
>>>
>>>
>>>
>>> On Sun, Apr 5, 2009 at 9:34 PM, Paul Cosgrove <paul.cosgrove_at_gmail.com
>>>
>>>> wrote:
>>>>
>>>
>>>
>>>> The standards are not static if course. There are often proposals to
>>>> update
>>>> existing standards, or to introduce new ones to replace them. TCP
>>>> extensions for high performance were published in 1992; ECN and the
>>>> authentication option being more recent examples Changes to 802.1d mean
>>>> that it is not as slow as it once was, RSTP having replaced the older STP
>>>> in
>>>> 2004.
>>>>
>>>> There have also been various changes to 802.1Q protocol. It was
>>>> originally
>>>> specified according to the old 802.1d standard, but MSTP was included in
>>>> the
>>>> ammendments added to the specification in 2003.
>>>>
>>>> The full context would make it clearer, but perhaps the author is using
>>>> layer 3 links with dynamic routing, instead of Layer 2 with MSTP.
>>>> Paul.
>>>>
>>>>
>>>> Pavel Bykov wrote:
>>>>
>>>>
>>>>
>>>>
>>>>> TRILL is the way to go, so is the OTV. but it only builds upon 802.1q,
>>>>> and
>>>>> does not replace it in any sense.
>>>>> Whoever said that "the 802.1q...is old and does not support the high
>>>>> bandwidth requirements for new services / applications." is a moron.
>>>>> First of all, the sentence does not makes sense. TCP is really old, like
>>>>> 30
>>>>> years old, but we are not in a hurry to replace it. OLD does not mean
>>>>> BAD.
>>>>> Second, it does not mention why it does not support the high bandwidth.
>>>>>
>>>>> What author may have meant, if he had any network experience, is that
>>>>> 802.1D
>>>>> (notice how .1D is not .1Q) is a protocol with many shortcomings,
>>>>> including
>>>>> slow convergence and absence of load balancing, which has to be provided
>>>>> by
>>>>> other standards, like 802.1AX, PVST, etc. And that routing will be used.
>>>>>
>>>>> But 802.1Q has no equal at this time. If you just want to use routing
>>>>> then
>>>>> that's fine, but it is substantially different than L2 service
>>>>> enablement
>>>>> which 802.1Q provides.
>>>>>
>>>>> P.S. forget ISL.
>>>>>
>>>>>
>>>>> On Wed, Apr 1, 2009 at 9:57 AM, Evan Weston <evan_weston_at_hotmail.com>
>>>>> wrote:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> I went to a Cisco event yesterday and one of the presenters mentioned
>>>>>> TRILL
>>>>>> https://cisco.hosted.jivesoftware.com/message/2747 thought it was
>>>>>> interesting...
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf
>>>>>> Of
>>>>>> Shahid Ansari
>>>>>> Sent: Wednesday, 1 April 2009 4:54 PM
>>>>>> To: Hash Aminu
>>>>>> Cc: Reza Toghraee; ccielab_at_groupstudy.com
>>>>>> Subject: Re: 10G ethernet and 802.1q
>>>>>>
>>>>>> Hash,
>>>>>>
>>>>>> worked with ISP and havent used ISL ,dot1q is best to go(q in q tunnel)
>>>>>> 1q also a standard across different vendors and guaranteed to work
>>>>>> between
>>>>>> different vendor equipments whereas ISL fails :)
>>>>>> regarding the VLANS ,who want to create more than 1K/4k Vlans?
>>>>>>
>>>>>> Thanks
>>>>>> Shahid
>>>>>>
>>>>>> On Tue, Mar 31, 2009 at 3:11 PM, Hash Aminu <hashng_at_gmail.com> wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>> Reza/Shahid,
>>>>>>>
>>>>>>> while i will agree with you that most of them are implying to cisco
>>>>>>> solution, I am aware of using 802.1q in cisco Gears can be less
>>>>>>> scalable
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> as
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>> the # of VLANs grows..hence you will run out of virtual ports (total #
>>>>>>> of
>>>>>>> Vlans passing thru a .1q trunk X the number of ports)..mostly the
>>>>>>> limits
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> is
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>> 6k per any line card.
>>>>>>>
>>>>>>> HTH
>>>>>>>
>>>>>>> Hash
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
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Received on Mon Apr 06 2009 - 15:38:28 ART