Subject: 3gpp-analysis-04: necessity for protocol translators in sect 2.3

From: Pekka Savola <[email-masked]>
Date: Tue, 22 Jul 2003 10:35:06 +0300 (EEST)

Hi,

This is the second issue for today; because it's heavily interconnected 
with the first bullet, I'm posting it at the same time.

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If the approach "use of NAT-PT in IPv6 UE -> IPv4 node" is accepted (and 
maybe even if not), I'd also modify section 2.3 slightly:

 1) the "Translators are typically needed" sounds too strong, and
                                                                               
 2) "two communicating nodes" does not address the peer-to-peer or other
non-client-server applications, so generalize the text to say just 
"communicating nodes"

------                                                                                                       
 2.3 Protocol Translators

    A translator can be defined as an intermediate component between a
    native IPv4 node and a native IPv6 node to enable direct
    communication between them without requiring any modifications to
    the end nodes.
                                                                                                       
    Header conversion is a translation mechanism. In header conversion,
    IPv6 packet headers are converted to IPv4 packet headers, or vice
    versa, and checksums are adjusted or recalculated if necessary.
    NAT-PT (Network Address Translator / Protocol Translator) [RFC2766]
    using SIIT [RFC2765] is an example of such a mechanism.

    Translators are typically needed when the two communicating nodes
    do not share the same IP version. Translation can actually happen
    at Layer 3 (using NAT-like techniques), Layer 4 (using a TCP/UDP
    proxy) or Layer 7 (using application relays).
                                                                                                       
modify the last paragraph to (for example):
                                                                                                       
    Translators may be needed in some cases when the communicating nodes
    do not share the same IP version. Translation can actually happen
    at Layer 3 (using NAT-like techniques), Layer 4 (using a TCP/UDP
    proxy) or Layer 7 (using application relays).

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

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From: "Christian Strauf (JOIN)" <[email-masked]>
Date: 22 Jul 2003 10:59:18 +0200

Hi,

>  2.3 Protocol Translators
I hope that this wasn't already addressed: wouldn't it be good to
mention Transport Relay Translators (TRT) (RFC 3142) here and in "3.4
IPv6 UE Connecting to an IPv4 Node"? Though I'm really not a fan of
NA(P)T-PT and similar, I really think that TRT is much more well-behaved
in terms of connection failures than NA(P)T-PT because of its way of
handling ICMP. So I personally think that it would fit into this context
quite nicely. Of course it still has many problems in common with
NA(P)T-PT when it comes to translating certain protocols.

Cheers,
Christian

-- 
JOIN - IP Version 6 in the WiN  Christian Strauf
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