Subject: [Softwires] Questions about draft-mdt-softwire-map-translation-01

From: Yuchi Chen <[email-masked]>
Date: Sat, 31 Mar 2012 12:59:04 +0800

Dear Murakami-San,

I'm very concerned about your work on MAP-T. I've read the
draft-mdt-softwire-map-translation-01, and I'm confused with some
statements in the draft. Questions are as follows:

1. In section 7.4, there is a statement saying "Otherwise, the IPv6
destination address (IPv4-translatable address) MUST be derived from
the received IPv4 destination address per DMR."
I'm wondering if the IPv4-translatable address here should be
IPv4-converted address.

2. In section 7.5, the expressions of "IPv6-converted address" and
"IPv6-translatable address" confused me. I am wondering if the
"IPv6-converted address" should be "IPv4-converted address"or not, and if
the "IPv6-translatable address" should be "IPv4-translatable address".

Here is are two pictures which depict my understanding of the draft.

Pic 1. Upstream from CE to BR:
CE
BR
IPv4 src    BMR              IPv6 src (IPv4-translatable)      FMR
 IPv4 src
-------------->
 -------------->
IPv4 dst    FMR, DMR     IPv6 dst (IPv4-converted)         DMR
 IPv4 dst

Pic 2. Downstream from BR to CE:
 CE
BR
IPv4 src     FMR, DMR    IPv6 src (IPv4-converted)         DMR       IPv4
src
 <--------------
 <--------------
IPv4 dst     BMR             IPv6 dst (IPv4-translatable)       FMR
 IPv4 dst

I'm not so sure if my understanding is right. Please correct me if there is
any mistake I've made. Thank you very much!

Best regards!
Yuchi Chen