Re: [OSPF] draft-ietf-ospf-segment-routing-extensions-03

[Peter Psenak <[e-mail]>]

Shraddha,

please see inline:

On 12/2/14 17:50 , Shraddha Hegde wrote:
> Authors,
> Some  comments on the draft.
>
>  1. The draft refers to the various use cases in the use case document
>     in I-D.filsfils-rtgwg-segment-routing. It’s useful to mention the
>     section of the use case draft which is applicable for each reference
>     instead of giving generic reference.

sure, we can add that.

>  2. Section 7.2 LAN Adj-sid sub TLV:
>
> Based on the description of the text it appears that the LAN AdjSID Sub
> TLV can contain multiple neighbor-ID /SID pairs based on the nodes
> attached to a broadcast network. The TLV diagram should depict carrying
> multiple such pairs.

no. LAN AdjSID Sub TLV only advertises a adj-SID for a single neighbor. 
If you have more non-DR neighbors, you need to advertise multiple LAN 
Adj-SID Sub-TLVs.


>         “It is used to advertise a SID/Label for an
>     adjacency to a non-DR node on a broadcast or NBMA network.”
> Does the above statement mean only DR originates the LAN-Adj SIDand
> advertises label to non-DR nodes?

no.

>        Shouldn’t each node in broadcast link originate LAN adj-SID and
> advertise label to all other nodes on the link?

For the adjacency to DR, Adj-SID Sub-TLV is used. For the adjacency to 
non-DR LAN Adj-SID Sub-TLV is used. It's done all all nodes on the LAN.

>
>  3. Adj-Sid sub TLV section 7.1:
>
> Description of V-flag mentions Prefix-SID,  it should be changed to Adj-SID.

good catch, will correct.

>
>  4. Section 4: Extended prefix range TLV is very similar to Extended
>     prefix TLV just that it has additional range associated with it.

yes, that is correct.

>
> I would think that we should have "route type" as in Extended prefix TLV
> instead of just having a bit indicating "inter area"

route-type would be misleading for range, as single range can include 
prefixes of various types (intra, inter, external). We have discussed 
this between authors and we agreed route-type is not the right way.

thanks,
Peter

> Rgds
> Shraddha