IPv4 Traffic Offload Selector Option for Proxy Mobile IPv6
Note: This ballot was opened for revision 07 and is now closed.
Brian Haberman Yes
(Ron Bonica) No Objection
Comment (2012-11-28 for -07)
The draft was much harder to read than it needed to be. Maybe rework would be a good idea.
(Stewart Bryant) No Objection
(Gonzalo Camarillo) No Objection
Benoit Claise (was Discuss) No Objection
Comment (2013-02-24 for -11)
Thanks for addressing my DISCUSS and COMMENT. Regards, Benoit
(Ralph Droms) (was Discuss) No Objection
Comment (2013-02-15 for -11)
Discuss position cleared 2013-02-15. While technically non-blocking, I would like the authors, the shepherd and the WG to consider them carefully as the document is revised. In my opinion, the document overspecifies some aspects of the protocol and includes redundant or otherwise unnecessary text. For example, sections 3.1 and 3.2 go into far more detail than required, and include unnecessary and untestable implementation details. Those two sections could be simply specified by text like: If the MAG is configured for offload, it includes an IPv4TS in its PBU sent to the LMA and installs the policy received in the IPv4TS in the PBA from the LMA. The MAG may provide a suggested policy in the IPv4TS it sends to the LMA. The MAG MUST install the policy received in the IPv4TS from the LMA, even if that policy is different from a suggested policy. The MAG MAY install a policy received in the IPv4TS in the PBA from the LMA if the MAG did not include an IPv4TS in the PBU. If the LMA receives a PBU that includes an IPv4TS, it determines the offload policy for the MN and returns it in an IPv4TS the PBA. The LMA MAY include an IPv4TS if the PBU does not include an IPv4TS. As another example, the discussion of how IPv6 offload might work is distracting. Simply say it's out of scope for this document. A nit in section 3: The parameters in the IP traffic selectors can be used to match against the header fields in the data packets. "are used by the MAG"? Otherwise, what's the point?
(Wesley Eddy) (was Discuss) No Objection
(Adrian Farrel) No Objection
Comment (2012-11-27 for -07)
Slightly puzzled... In the IPv4 Traffic Offload Selector Option you have The traffic selector sub-option includes the parameters used to match packets for a specific flow binding. This is an optional field when this option is used only a capability hint. There is only one other field in the IPv4 Traffic Offload Selector Option and that is the M bit which describes how to interpret the traffic selector sub-option. So, it the traffic selector sub-option is optional, then what is the purpose of the whole IPv4 Traffic Offload Selector Option?
Stephen Farrell (was Discuss) No Objection
Comment (2013-02-11 for -09)
comments not updated for -09 so may be fixed already (or wrong;-) - 3.1 and elsewhere, it seems wrong to talk about configuration variables like EnableIPTrafficOffloadSupport since that's implementation specific. That would be better changed to say e.g. "If the LMA is configured to turn on offloading..." or similar. - 3.1, last para: why is this only a SHOULD NOT and when would it be ok to send back the selection option if it wasn't requested by the MAG? Given that the MAG SHOULD ignore this anyway (last para of 3.2) this seems to add complexity for no real benefit. - sections 3 & 4, "M" flag - why are these SHOULDs? Wouldn't all MUSTs be cleaner? - section 4: repeating text from rfc 6089 is fine, but shouldn't you say whether that or the text here takes precedence in the event that e.g. 6089 is updated or obsoleted? (And which is the repeated text anyway, that's not clear to me at least.) - Some examples would be good, esp. for something a bit complex but likely to be wanted, e.g. offload all HTTP except these servers on port 443, if that's supported. (Its not clear to me to be honest.)
(Russ Housley) No Objection
Barry Leiba No Objection
Comment (2012-11-26 for -07)
This was a difficult read. I have to strongly agree with the document shepherd, who says in the writeup, "The readbility of the document could be improved. As part of the chair review this has been suggested to the authors." That said, I think the RFC Editor can deal with the situation, and I have no objection to approving this document. Just some non-blocking comments that I'd like the authors to consider: -- Section 1 -- A given operator may choose to offload all traffic except that which requires QoS services (Ex: Voice over IP traffic), or may choose to offload all HTTP traffic. It's not clear whether VoIP is an example of what the operator *would* offload, or of what they wouldn't. I gather it's the latter. It's also possible to read this as having to choose one of these options or the other (everything except QoS traffic, or HTTP traffic). In fact, you're just giving examples. Why not try this?: NEW One operator might choose to offload everything except traffic (such as Voice over IP) that requires QoS services. Another might choose to offload only HTTP traffic. -- Section 1 -- This approach has one limitation with respect to identifying encrypted traffic. IPsec encrypted traffic with no visibility into the application payload cannot be selected for offload. The first sentence introduces the second, and the second specifies what's said in the first (they're not two independent things). In this case, it's better to write them as one sentence with a colon, rather than as two sentences: NEW This approach has one limitation with respect to identifying encrypted traffic: IPsec encrypted traffic with no visibility into the application payload cannot be selected for offload. -- Section 1, Last paragraph -- Is there a reference you can cite for prefix coloring work? -- Section 3 -- You should refer to Figure 1 somewhere in the text. -- Section 5 -- I recommend adding a second paragraph, to make sure this isn't forgotten: RFC Editor: please replace "<IANA-1>" in Section 4 with the assigned value, and remove this paragraph.
(Pete Resnick) (was Discuss) No Objection
Comment (2013-02-12 for -09)
This version removes the really egregious uses of 2119 to impose particular implementation style. Thanks for that. There are some remaining silly ones in 3.2 and 3.3 that I hope you will fix: 3.2: OLD o If the mobile access gateway is configured to support IPv4 Traffic Offload support, then it SHOULD include the IPv4 Traffic Offload Selector option (Section 3.1) in the Proxy Binding Update message that it sends to the local mobility anchor. NEW o If the mobile access gateway is configured to support IPv4 Traffic Offload support, then it includes the IPv4 Traffic Offload Selector option (Section 3.1) in the Proxy Binding Update message that it sends to the local mobility anchor. I don't really understand what the SHOULD was doing there in the first place. Are there circumstances where the MAG wouldn't include the selector? Either way, this is simply a description of actions to be taken, not a warning to implementers about what the MUST or SHOULD do. OLD In this scenario, the IPv4 Traffic Offload Selector option that is carried in the Proxy Binding Update message MUST NOT include the Traffic Selector sub-option (Section 3.1) and the (M) flag Section 3.1 in the option MUST be set to value of (0). NEW In this scenario, the IPv4 Traffic Offload Selector option that is carried in the Proxy Binding Update message does not include the Traffic Selector sub-option (Section 3.1) and the (M) flag Section 3.1 in the option is set to value of (0). As above. 3.3: OLD o If the Proxy Binding Update message includes the IPv4 Traffic Offload Selector option, but if the local mobility anchor is not configured to support IPv4 Traffic Offload support, then the local mobility anchor MUST ignore the option and process the rest of the message as per [RFC5213]. NEW o If the Proxy Binding Update message includes the IPv4 Traffic Offload Selector option, but the local mobility anchor is not configured to support IPv4 Traffic Offload support, then the local mobility anchor will ignore the option and process the rest of the message as per [RFC5213]. The LMA doesn't have to make a choice whether to ignore the option. It always ignores the option because it's not configured to support it. So telling it that it MUST ignore the option is silly. OLD o If the Proxy Binding Update message has the IPv4 Traffic Offload Selector option and if the local mobility anchor is configured to support IPv4 Traffic Offload support, then the local mobility anchor MUST enable IPv4 Traffic Offload support for that mobility session. The Proxy Binding Acknowledgement message that will be sent in response MUST include the IPv4 Traffic Offload Selector option. NEW o If the Proxy Binding Update message has the IPv4 Traffic Offload Selector option and the local mobility anchor accepts the request, then the local mobility anchor enables IPv4 Traffic Offload support for that mobility session and sends a Proxy Binding Acknowledgement message in response that includes the IPv4 Traffic Offload Selector option. The first MUST worries me. You are not telling me that I can't build an LMA that ignores offload requests from certain MAGs, are you? I can't believe that this would be a protocol violation. The second MUST is just unnecessary.
(Robert Sparks) No Objection
Martin Stiemerling No Objection
(spt) No Objection
Comment (2012-11-28 for -07)
Updated I'd echo this draft was a bit of a challenge to follow. if you look at the protocol flow in f2, I'd have expected to read about the MAG first since it starts the protocol instead you went with the LMA. Then in the LMA section instead of going with what it has to deal with when it receives something from the MAG you go with what the LMA must not send. Just a bit backward for me - but this is just a comment so do with it what you will. If the definition for IP Flow from 5101 can't be used maybe the one from 3917? I also didn't follow how you handle a case where an LMA overrides what the MAG tries to set up and the MAG doesn't support it. drafts says: "This option is carried like any other mobility header option as specified in [RFC5213] and does not require any special security considerations." It's misleading IMHO. This option does require security considerations since an attacker, by sending fake signaling messages, may prevent a mobile network from offloading traffic which may lead to a DoS. You'd better say something like: "This option is carried like any other mobility header option as specified in [RFC5213]. Therefore it inherits from [RFC5213] its security guidelines and does not require any additional security considerations." Typos: Section 1: s/its only about IPv4/it is only about IPv4/