Re: Two-octet bandwidth values

[Bora Akyol <akyol@pluris.com>]

I believe the argument is over an accuracy of 67 Mbps (out of an OC768c) 
not 10s of bits/sec.

I am not convinced that this TLV is needed.

Bora

On Tuesday, March 27, 2001, at 07:03 PM, Frank Hujber wrote:

> I guess, if the need to specify down to the tesn of bits per second is
> critical, then the only way is to find a way to expand the IEEE floating
> point format. Ugly.
>
> Is the possibility of adding a sub-TLV for this all that objectionable?
>
> Frank
> fhujber@hotmail.com
>
> ----- Original Message -----
> From: "Bora Akyol" <akyol@pluris.com>
> To: "Frank Hujber" <fhujber@hotmail.com>
> Cc: "Kireeti Kompella" <kireeti@juniper.net>; "CCAMP List"
> <ccamp@ops.ietf.org>; "John Drake" <jdrake@calient.net>
> Sent: Tuesday, March 27, 2001 8:08 PM
> Subject: Re: Two-octet bandwidth values
>
>
>> Frank
>>
>> Bonds are not proprietary, our implementation (even though implemented
>> independently and without knowledge of the document) is quite a like 
>> the
>> PPP LBD draft in the PPP-EXT working group.
>>
>> The point is that 10 bits is not enough to represent large chunks of
>> bandwidth accurately.
>>
>> Bora
>>
>>
>> On Tuesday, March 27, 2001, at 01:44 PM, Frank Hujber wrote:
>>
>>> It occurs to me that the smallest increment of reservable bandwidth,
>>> from a
>>> practical perspective, is a DS1 (1.544 Mbps). If this is so, why do we
>>> need
>>> to be able to represent values to +/- 10bps?
>>>
>>> The builders of OXCs and PXCs can see down the road to OC-3072 even
>>> though
>>> there's not much being spent on it in the lab just yet, and some of
>>> aren't
>>> even looking much further back than OC-48. "Bonds" sound linke a
>>> proprietary
>>> implementation which no one will want to be beholden to.
>>>
>>> This ought to be considered further, even if it has to be put in a
>>> separate
>>> sub-TLV for backward compatibility reasons.
>>>
>>> Frank Hujber
>>> fhujber@hotmail.com
>>> ----- Original Message -----
>>> From: John Drake <jdrake@calient.net>
>>> To: 'Bora Akyol' <akyol@pluris.com>; Kireeti Kompella
>>> <kireeti@juniper.net>
>>> Cc: <ccamp@ops.ietf.org>; <OSPF@DISCUSS.MICROSOFT.COM>
>>> Sent: Monday, March 26, 2001 8:36 PM
>>> Subject: RE: Two-octet bandwidth values
>>>
>>>
>>>> ditto
>>>>
>>>> -----Original Message-----
>>>> From: Bora Akyol [mailto:akyol@pluris.com]
>>>> Sent: Monday, March 26, 2001 5:16 PM
>>>> To: Kireeti Kompella
>>>> Cc: ccamp@ops.ietf.org; OSPF@DISCUSS.MICROSOFT.COM
>>>> Subject: Re: Two-octet bandwidth values
>>>>
>>>>
>>>>
>>>> On Sunday, March 25, 2001, at 08:05 PM, Kireeti Kompella wrote:
>>>>
>>>>> Let's get the ball rolling.  Please send questions and comments to 
>>>>> the
>>>>> list.  Here are mine:
>>>>>
>>>>> Questions to vendors:
>>>>> 1) Is floating point arithmetic a burdensome requirement?  Is having
>>>>>    a new library of functions for the two-octet "floating point"
>>>>>    representation a burdensome requirement?
>>>>>
>>>>
>>>> I don't see what exactly is wrong with the present approach, we have 
>>>> no
>>>> problem working with the present TE TLVs and no problems with 
>>>> floating
>>>> point.
>>>>
>>>>> 2) Is halving the size of the bandwidth TLVs a big win (keep in mind
>>>>>    that more bandwidth TLVs are being proposed)?
>>>>>    (a) for ISIS?
>>>>>    (b) for OSPF?
>>>>>    (c) if the answers for ISIS and OSPF differ, is it acceptable to
>>>>>        have different formats for the two protocols?
>>>>>
>>>>
>>>> I think it is unacceptable to have OSPF and ISIS TE TLVs differ. I
>>>> think
>>>> halving the size of the bandwidth TLVs is not very useful. It causes
>>>> yet
>>>> another "transition" problem just as people are getting used to the
>>>> present scheme.
>>>>
>>>>
>>>>> Questions to vendors & carriers:
>>>>> 1) Is 10 bits of dynamic range (0.1% accuracy) good enough?
>>>>>
>>>> This depends a lot on the bandwidth, on an OC768c this will translate
>>>> to
>>>> a whopping 400 Mbps, which to me is inadequate.  Our routers also
>>>> support bundled links which we call "Bonds" that can achieve 
>>>> bandwidths
>>>> much larger than 40 Gbps. So my answer to 10 bits of dynamic range is
>>>> NO.
>>>>
>>>>> 2) Are you in favor of this draft, or against?
>>>>>
>>>>
>>>> Seems like we have more important stuff to focus on then this
>>>> particular
>>>> topic.
>>>>
>>>> Bora
>>>>
>>>>
>>>
>>
>>
>