Re: [Pce] FW: New Version Notification for draft-lee-pce-transporting-te-data-00.txt

[Ramon Casellas <[e-mail]>]

El 18/07/2014 7:39, Ramon Casellas escribió:
> El 17/07/2014 18:42, Leeyoung escribió:
>> Hi Jeff,
>>
>> I have a similar comment with Dhruv. I am wondering how BGP-LS 
>> packages together TE information. Wouldn't it require IGP-TE to give 
>> TE link-state information to BGP-LS speaker, then BGP-LS packages 
>> them into a summary TE-info? If this is the case, I am not sure how 
>> convergence time of BGP-LS can improve that of IGP-TE? Please correct 
>> me if my understanding is not wrong.
>
> Young, all
>
> As much as I am ok with the approach of using PCEP, I am not sure what 
> you say is always the case. I would guess that the common, 
> straightforward source of link-state information for BGP-LS is the 
> IGP-TE, but it does not preclude other sources, including, as per 
> draft-ietf-idr-ls-distribution direct, static and unknown.
>
That said, re-reading the draft again, the actual text still clearly 
shows a heavy dependency on the IGP, e.g.

* $3.2.1.4 "IGP Router ID: opaque value.  This is a mandatory TLV" lists 
IS-IS and OSPFv2/v3

* $3.2.2, "Although the encodings for 'Link Descriptor' TLVs were 
originally defined for IS-IS, the TLVs can carry data sourced either by 
IS-IS or OSPF"

* $3.5 "The main source of TE information is the IGP,"

etc. etc.

Of course, e.g. assigning a router ID to a node does not mean that an 
instance is actually running, so I guess BGP-LS could be decoupled from 
the IGP instance (although using similar encodings and modulo some text 
adjustments) thus mitigating convergence issues?

Thanks,
R.