Subject: [BEHAVE] Handling of fragmented UDP packets with zero checksum

From: Simon Perreault <[email-masked]>
Date: Fri, 04 Dec 2009 09:54:25 -0500

Hello,

In draft-ietf-behave-v6v4-xlate-04, section 2.2, we have the following:

   When a stateful translator receives fragmented UDP IPv4 packets and
   the checksum field is zero, if the translator has enough resource to
   reassemble the packets, the stateful translator SHOULD reassemble the
   packets and SHOULD calculate the checksum.  Otherwise, the stateful
   translator MAY drop the packets.

- Any reason the second SHOULD in the second paragrah ("SHOULD calculate the
checksum") isn't a MUST?

- In the second paragraph, doesn't the first SHOULD ("SHOULD reassemble")
conflicts with the MAY ("MAY drop")?

Suggestion: Change to the following:

   When a stateful translator receives fragmented UDP IPv4 packets and
   the checksum field is zero, if the translator has enough resource to
   reassemble the packets, the stateful translator SHOULD reassemble the
   packets. In that case, it MUST calculate the checksum.  Otherwise, the
   stateful translator MUST drop the packets.

Thanks,
Simon
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