Re: [radext] Mirja Kühlewind's Discuss on draft-ietf-radext-ip-port-radius-ext-11: (with DISCUSS)

[<[e-mail]>]

Dear Mirja, 

Please see inline. 

Cheers,
Med

> -----Message d'origine-----
> De : radext [mailto:[e-mail]] De la part de Mirja
> Kuehlewind
> Envoyé : mercredi 17 août 2016 16:04
> À : The IESG
> Cc : [e-mail]; MORAND Lionel IMT/OLN;
> [e-mail]; [e-mail]
> Objet : [radext] Mirja Kühlewind's Discuss on draft-ietf-radext-ip-port-
> radius-ext-11: (with DISCUSS)
> 
> Mirja Kühlewind has entered the following ballot position for
> draft-ietf-radext-ip-port-radius-ext-11: Discuss
> 
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> The document, along with other ballot positions, can be found here:
> https://datatracker.ietf.org/doc/draft-ietf-radext-ip-port-radius-ext/
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> 
> 
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
> 
> I fully support Alissa's discussion points and have two more to add:
> 
> 1) IP-Port-Type TLV only covers UDP, TCP and ICMP. This is not very
> future-proof: there are other transport protocols that have ports or
> identifiers that may want to be supported in future.

[Med] This is a fair comment. FWIW, only TCP/UDP/ICMP are covered initially in the draft because those are currently the only ones supported by widely deployed CGNs. 

 Also it is not clear
> to me from the document why this information is needed at all in the
> described use cases.

[Med] Because ports are bound to a transport protocol (e.g., of the port forwarding in Section 4.1.3). In modern NATs, when an (explicit/implicit) mapping is created, a port is reserved only for a given transport protocol not for all transport protocols. 

 Therefore I see two possible ways forward: Either
> remove the IP-Port-Type TLV or extend it to also cover other cases.

[Med] The new version of the draft extends the TLV to be applicable to other transport protocols. We are using the IANA protocol numbers (http://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml).  

> 
> Related to this point I would like to mention that RFC6887 is not
> restricted to UDP/TCP and therefore the following sentence in section 2
> is not correct:
> "Note that the definitions of [...] "internal port", [...] "external
> port" [...] are the same as defined in Port Control Protocol (PCP)
> [RFC6887]"

[Med] This is not an issue given that the new version of the draft is not restricted to TCP/UDP.