Hi Linda,

>> Therefore, I think it is better to have a flag indicating if the VNs are
>> listed individually, Upper/Lower ranges, or bit mapped.
>>
>I wouldn't use a flag for that, it's probably cleaner to define
>another TLV type that gives a list of VNIDs. Either the list or
>bit-map can be used interchangeably.

I also think separate TLVs should be specified. Thus we will have three types 
of TLV to encode the VNID list: 
(1) VNIDs listed individually; 
(2) Ranges with Upper/Lower bounds; 
(3) One or *multiple* bit-maps of VNIDs.

Since it's still possible that a single TLV is too large by using any of the 
TLVs so fragmentation should be specified as well. 

Thanks,
Mingui




>-----Original Message-----
>From: nvo3 [mailto:[email protected]] On Behalf Of Tom Herbert
>Sent: Friday, January 30, 2015 6:27 AM
>To: Linda Dunbar
>Cc: [email protected]; [email protected]
>Subject: Re: [nvo3] is it resonsable that
>draft-dunbar-nvo3-nva-mapping-distribution-01 suggests NVE using bit-map to
>represent its supported VNs?
>
>On Thu, Jan 29, 2015 at 1:53 PM, Linda Dunbar <[email protected]>
>wrote:
>> When a NVE is initialized or re-started, it uses Virtual Network scoped
>> instances of the IS-IS to announce all the Virtual Networks in which it is
>> participating.
>>
>>
>>
>> The  current draft-dunbar-nvo3-nva-mapping-distribution-01 suggests using
>> the bit map to represent the supported VNs.
>>
>>    +-+-+-+-+-+-+-+-+
>>
>>    |     Type      |                  (1 byte)
>>
>>    +-+-+-+-+-+-+-+-+
>>
>>    |   Length      |                  (1 byte)
>>
>>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>
>>    | RESV  |  Start VN ID          |  (2 bytes)
>>
>>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>
>>    | VNID bit-map....
>>
>>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>
>> Figure 2. Enabled-VN TLV
>>
>Hi Linda,
>
>First a couple of meta comments on the draft:
>
>- Sizes of type and lengths in TLVs are inconsistent (some 16 bits,
>some 32 bits). It might be just as well to make all of them 16 bits.
>- For the above, I think the Start VNID field is 4 bytes not 2 bytes.
>- Please avoid implicitly setting constraints on the data plane in the
>definition of control plane. For instance, I've already made arguments
>that VN ID might be thirty-two bits, and there's little cost to
>defining thirty-two bit VN IDs in the control plane.
>
>>
>>
>>
>>
>> For 24-bits VN ID, there could be 16million VNs. Even with the “Start VN ID”
>> listed, the number of bytes for the bitmap can be very large.
>>
>>
>>
>> Therefore, I think it is better to have a flag indicating if the VNs are
>> listed individually, Upper/Lower ranges, or bit mapped.
>>
>I wouldn't use a flag for that, it's probably cleaner to define
>another TLV type that gives a list of VNIDs. Either the list or
>bit-map can be used interchangeably.
>
>Tom
>
>>
>>
>> Any other suggestions?
>>
>>
>>
>> Linda
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> nvo3 mailing list
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>> https://www.ietf.org/mailman/listinfo/nvo3
>>
>
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