Re: FW: Two-octet bandwidth values

[Bora Akyol <akyol@pluris.com>]

So it looks like the right thing to do is to separate non-routing 
essential TLVs from the routing essential TLVs.

It seems to me that the IGPs are being used as a reliable multicast 
protocol to distribute mostly non-routing related information.

Is there anyway in which we can distribute this information in a 
separate packet not limited by 244 bytes?


Bora


On Monday, March 26, 2001, at 08:38 PM, Qingming Ma wrote:

> Hello everyone,
>
> Thanks for comments!  As Dean pointed out, the focus of this
> draft is on space, particular ISIS sub-TLV space,  which is
> limited to 244 bytes (255 - 11). As stated in Tony Li's ISIS-TE
> extensions draft that there is no defined mechanism for extending
> sub-TLV space and wasting sub-TLV space is discouraged.
>
> Considering the current situation, the total sub-TLV size for generic
> TE extensions, GMPLS extensions, and DiffServ TE extensions
> together is 222 bytes without taking into account of alignment.
> There is no enough sub-TLV space for the proposed LSP
> restoration draft if we want to go with them. More extensions related to
> TE and/or Optical Control may be proposed in future. New TLVs
> may have to be defined  to accommodate new extensions if we do not
> conserve sub-TLV space now. By using two-octet BW values, the
> total sub-TLV size for all three types of extensions mentioned above
> can be reduced to 138 bytes.
>
> For OSPF, the sub-TLV space is not a urgent issue at this time.
> But short LSAs are always encouraged to reduce routing overhead.
>
> For backward compatibility, we may define new types for BW
> sub-TLVs that use two octets. Since there are plenty of unused
> types, it should not be a problem.
>
> Thanks,
>
> Qingming
>
> At 03:26 PM 3/26/01 -0800, Cheng, Dean wrote:
>
>
>> Also, since the "draft-katz-yeung-ospf-traffic-03.txt"
>> may be going to a RFC soon, would it be necessary to
>> consult with the OSPF WG at this point as well ?
>>
>> -----Original Message-----
>> From: Kireeti Kompella [mailto:kireeti@juniper.net]
>> Sent: Sunday, March 25, 2001 8:06 PM
>> To: ccamp@ops.ietf.org
>> Subject: Two-octet bandwidth values
>>
>>
>> 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 think the point for the two-octet approach is to save
>> packet space (or link resource), not work complexity.
>>
>> 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?
>> Yes
>>    (b) for OSPF?
>> Yes
>>    (c) if the answers for ISIS and OSPF differ, is it acceptable to
>>        have different formats for the two protocols?
>>
>> Questions to vendors & carriers:
>> 1) Is 10 bits of dynamic range (0.1% accuracy) good enough?
>>
>> Yes
>> 2) Are you in favor of this draft, or against?
>>
>> Yes
>>
>> Kireeti.
>>
>> Dean
>
>