The Use of Entropy Labels in MPLS Forwarding
RFC 6790
Yes
No Objection
Note: This ballot was opened for revision 06 and is now closed.
(Adrian Farrel; former steering group member) Yes
(Stewart Bryant; former steering group member) Yes
I am voting Yes on this useful and mainly well written document, however
I do have some comments that I would request that the authors and
responsible AD consider.
In section 4.1
"If an ingress X chooses"
I think that is an ingress LSR (although you define it later
this is the first time we meet "X")
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"This is to avoid jitter, latency and re-ordering issues for the flow."
Re-order for sure, but I don't see how jitter and latency come into
play.
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"1. at the ingress LSR, MPLS encapsulation hasn't yet occurred, so
deep inspection is not necessary;"
Some people would consider a network layer device looking
at the transport headers to do ECMP as a DPI.
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"On the other hand, an ingress LSR (e.g., a PE router) has detailed
knowledge of an packet's contents, typically through a priori
configuration of the encapsulation(s) that are expected at a given
PE-CE interface, (e.g., IPv4, IPv6, VPLS, etc.). They also have more
flexible forwarding hardware."
The last sentence is disputable because it is highly implementation
dependent. There are ASIC and even Network Processor based
PEs that will not be able to push as the extra labels. I would delete
the last sentence.
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3. Entropy Labels and Their Structure
Entropy labels are generated by an ingress LSR, based entirely on
load balancing information. However, they MUST NOT have values in
the reserved label space (0-15) [IANA MPLS Label Values].
Did I miss this reference to [IANA MPLS Label Values]?
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"for multicast LSPs will be specified in a companion document."
Companion or future? I don't think it is yet a WG draft
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Section 8.1, 8.2 and 8.3 are quite hard to follow. They are only
informational, so it would probably be better if they were in
an appendix, so that any errors will not impact the protocol
definition.
It would also really help the reader if some text were
provided in each case explaining what is happening. Once
the first example has been explained in detail, many of the others
just need text describing the delta.
(Barry Leiba; former steering group member) No Objection
(Benoît Claise; former steering group member) No Objection
(Brian Haberman; former steering group member) No Objection
(Gonzalo Camarillo; former steering group member) No Objection
(Martin Stiemerling; former steering group member) No Objection
(Pete Resnick; former steering group member) No Objection
(Ralph Droms; former steering group member) No Objection
(Robert Sparks; former steering group member) No Objection
(Ron Bonica; former steering group member) No Objection
(Russ Housley; former steering group member) No Objection
(Sean Turner; former steering group member) No Objection
(Stephen Farrell; former steering group member) No Objection
Security considerations: if the EL value is calculated only based on packet headers then a relatively efficient wiretapping interface could be added depending on the function used to generate the EL value. If a network didn't want that to be possible or too easy then it could add some other input to the generation of the EL values that'd make it harder to build a table of EL values to tap given knowledge of the keys from the packet. For example the ingress LSR could generate a random input to the EL generation process every so often. I've no idea if that's practical nor worth inclusion but thought I'd mention it anyway just in case.
(Wesley Eddy; former steering group member) No Objection