Re: Two-octet bandwidth values

[Bora Akyol <akyol@pluris.com>]

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
>>
>>
>