Hi Mrinmoy, I will give authors some time to respond and confirm (and spin a new update). I have noted this in the PCE WG wiki [ https://trac.ietf.org/trac/pce/wiki/WikiStart ] to make sure we could track this to closure.
Thanks! Dhruv On Tue, Mar 24, 2020 at 7:11 PM Mrinmoy Das <[email protected]> wrote: > > Hi Dhruv, > > Thanks for your quick reply. > > I have added PCE WG in this mail. More inline. > > Thanks & Regards, > Mrinmoy > > On Tue, Mar 24, 2020 at 6:00 PM Dhruv Dhody <[email protected]> wrote: >> >> Hi Mrinmoy, >> >> I was suggest you to also include [email protected]; WG could benefit from >> the discussion in future. More inline. >> >> On Tue, Mar 24, 2020 at 5:08 PM Mrinmoy Das <[email protected]> wrote: >> > >> > Respected Authors and Contributors, >> > >> > Hope you all are doing well and safe in this tough times of Corona Virus >> > Outbreak. >> > >> > I like to draw your attention regarding some parts of >> > draft-ietf-pce-binding-label-sid-02 which I didn't able to understand >> > properly. >> > >> > 1. BT = 0: The binding value is an MPLS label carried in the format >> > >> > specified in [RFC5462] where only the label value is valid, and >> > other fields (TC, S, and TTL) fields MUST be considered invalid. >> > The Length MUST be set to 7. >> > >> > >> > Previous versions of private draft uses 4 byte to store MPLS 20 Bit >> > label and ignores TC, S & TTL fields. >> >> The length in the previous version was 6, which was incorrect. The TLV >> length is as per https://tools.ietf.org/html/rfc5440#section-7.1 >> Which didnt make sense and your calculation below is correct! >> >> > But in IETF draft after TLV structure redefinition, total length of >> > the TLV becomes 7, i.e. BT(1 Byte)+Reserved(3 Byte)+MPLS 20bit Label(3 >> > Byte) = 7 Byte >> >> Yes >> >> > So, now MPLS 20 Bit Labelwill be stored in 3 byte. Is it correct? >> >> You can consider it a case of rounding up 20 bits to 3 bytes. >> >> >> > If this is correct then I feel the wording of the above paragraph >> > needs to be more specific, meaning in 3 Byte Label there will be no space >> > for TTL, so >> > my suggestion is to make below correction: >> > >> > BT = 0: The binding value is an MPLS label carried in the format >> > >> > specified in [RFC5462] where only the label value is valid, and >> > other fields (TC, S, and TTL) fields MUST be considered invalid. >> > The Length MUST be set to 7. >> > >> >> My suggestion would be not mention any of the other fields and talk >> only of 20 bits of Label. I see other SR RFCs take similar approach. > > > Sounds Good. I'm agree with you. > >> >> > >> > 2. In some cases, a stateful PCE can request the PCC to allocate a >> > >> > binding value. It may do so by sending a PCUpd message containing an >> > empty TE-PATH-BINDING TLV, i.e., no binding value is specified >> > (making the length field of the TLV as 2). A PCE can also make the >> > request PCC to allocate a binding at the time of initiation by >> > sending a PCInitiate message with an empty TE-PATH-BINDING TLV. >> > >> > >> > As per new Binding TLV Structure below, BT is of 1 Byte and there will >> > be 3 Byte Reserved. >> > >> > 0 1 2 3 >> > >> > 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 >> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >> > | Type | Length | >> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >> > | BT | Reserved | >> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >> > ~ Binding Value (variable length) ~ >> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >> > >> > >> > Now, an empty Binding TLV should have length of BT(1 Byte) + Reserved >> > (3 Byte) = 4 Byte instead of 2 Byte. >> > >> > So, I do not understand how in the draft it is calculated as 2 Byte. >> > Could you please give me some clue? >> >> >> This seems to be an error IMHO. 4 seems to be correct. > > > Okay. So what would be your suggestion to developer who is implementing this > draft? Should it be taken as 4? If draft needs correction > when will that be published? >> >> >> Thanks! >> Dhruv >> >> > >> > Thanks & Regards, >> > Mrinmoy _______________________________________________ Pce mailing list [email protected] https://www.ietf.org/mailman/listinfo/pce
