IP-ID of ROHCv2

Dear ROHC WG,

Today I want to raise a concern and learn your comments about one section of RFC 5225. I see a potential violation of transparency and integrity concept of compression in red colored sentence.

Basically IP-ID of tunneling headers is decided by the tunnel ingress/egress nodes but not by a compressor/decompressor pair in the middle of transit.  Does the red colored sentence require the overwriting of IP-ID field?

I guess it shouldn't. Otherwise it may cause non-conformance to security protocols.

Thank you,
Jiwoong


6.3.3.  IP-ID Behavior
   ...
   ROHCv2 profiles MUST NOT assign a sequential behavior (network byte
   order or byte-swapped) to any IP-ID but the one in the innermost IP
   header when compressing more than one level of IP headers.  This is
   because only the IP-ID of the innermost IP header is likely to have a
   sufficiently close correlation with the MSN to compress it as a
   sequentially changing field.  Therefore, a compressor MUST assign
   either the constant zero IP-ID or the random IP-ID behavior to
   tunneling headers.

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