Hi Wojciech,

two comments on the 3gpp sections of draft-dec-stateless-4v6-02.

First, the definition of "Rx" is missing in section 4.2.1.

Second, the table in section 4.2.2 claims "No discernible impact" for
"AF Application Function" for the 4V6 translation mode. This is not
fully correct.
The PCC architecture support a plurality of AFs communication over Rx
with the PCRF, and most of them "interact" in some way with the end
user payload.
An AF might terminate, proxy or transparently inspect a subset of the
UE traffic (for instance control signalling, like SIP).
An AF might also terminate, proxy or transparently inspect all UE
traffic (application server acting as AF, deep packet inspection
device, ...).
And the most important point: An AF might located in different
locations inside the operators networks, or even outside the operators
network.
Referring to your own "Figure 2" in the draft, this means that for
IPv4 traffic an AF might "intercept" traffic between the "PDN-Gw" and
the "S46 Gateway", i.e. with an IPv6 header, BUT it might also
intercept traffic behind the "S46 Gateway", i.e., with an IPv4 header.

I propose to change the impact to "No impact for IPv6. Feature to map
IPv4-IPv6 addresses may be needed only in case of  IPv4-only
applications".

I'm aware that it would be theoretically possible to "hide" this
impact from an AF by using a more complex PCRF implementation that
"translates" IPv4 addresses in Rx message (including TFTs) into the
mapped IPv6, but this would imply limitations, and would just be one
implementation possibility. I believe that this draft should not
assume a specific implementation, unless clearly documented.

br,
  Paco
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