Hi Longwei,
I have a few questions:
#1:
3.1. Reliable transmission for confirmable LW-GRASP messages
...
If the LW-GRASP confirmable message does not get an acknowledgment within the
retransmission timeout, then the message MUST be retransmitted, but there is no
need to regenerate the Nonce, just keep it the same as the original message.
What happens if the recipient has accepted the message and processed it, but
the acknowledgment is lost? Some GRASP messages (especially M_NEGOTIATE) are
not idempotent, so simply repeating a message could be dangerous.
I think this requires some extra specification - the recipient must also cache
the nonce in order to detect repeats. I think a repeat needs to be
acknowledged, but not processed a second time.
#2:
I don't see a discussion of message integrity (i.e. the replacement for the TCP
checksum). Are you relying on the UDP checksum? Is there a negative
acknowledgment if there is a checksum error?
#3:
4.2.1. LW-Objective option
...
objective-num = 0..255
CBOR does not require you to limit this to 8 bits. So you could define it as
larger, e.g. 16 bits, but start assigning from zero; that would make no
difference on the wire unless you actually *needed* more than 256 values.
Also, do you expect the objectives to be standardised and registered like normal GRASP objectives, or will they be
local? This needs to be explained. For example, if you wanted to use "PrefixManager" and
"PrefixManager.Params" from RFC8992, would you give them numbers in addition? ("PrefixManager" =
10, "PrefixManager.Params" = 11)
#4:
7. Security Considerations
The security people insisted that in RFC 8990, we specified use of TLS even
over the ACP. This was for defence against internal attackers. (I did implement
an alternative, draft-carpenter-anima-quads-grasp, but it still needs a full
crypto library.)
Regards
Brian
On 05-Jul-24 01:29, 朱龙薇 wrote:
Dear ANIMA WG members,
We have proposed the draft “Lightweight GeneRic Autonomic Signaling
Protocol”(draft-zhu-anima-lightweight-grasp-00,
https://datatracker.ietf.org/doc/draft-zhu-anima-lightweight-grasp/).
The draft aims to design a lightweight version of GRASP, i.e., LW-GRASP, with
shortened messages and a message-oriented built-in reliability mechanism with
the acknowledgment and retransmission capability based on Nonce. The LW-GRASP
can work reliably over UDP, which avoids additional overhead caused by TCP，thus
can be more suitable for resource-constrained IoT nodes. Furthermore, the
possible IP-independent method for LW-GRASP is also discussed.
We would like to hear opinions from the WG. All kinds of comments are welcome.
Thanks
Longwei Zhu
_______________________________________________
Anima mailing list -- [email protected]
To unsubscribe send an email to [email protected]
_______________________________________________
Anima mailing list -- [email protected]
To unsubscribe send an email to [email protected]
