Subject: [siprec] Comments on draft-eckel-siprec-rtp-02

From: "Elwell, John" <[email-masked]>
Date: Thu, 22 Sep 2011 09:11:00 +0200

1. In section 4, I like the new figure 2, but it would perhaps be better to label the SRC as:

	SRC
     B2BUA

Charles,

Thanks for posting the new draft. Looking at the diffs I noticed a couple of things:

1. It would be good to align figure a to show the RS as a vertical line, as in figure 2. Also the SRC should be labelled as

	SRC
      UA2

e.g.:

                                     SRS
                                      ^
                                      |
                                     RS
                                      |
                                      v
                                     SRC
                      UA1 <-- CS --> UA2

2. In 4.1.2:
"If SRTP is used on both the CS and the RS, decryption and/or re-  
       encryption may occur.  For example, if different keys are used, it  
       will occur.  If the same keys are used, it need not occur."
Since we are talking in this section about a transcoding translator, transcoding will necessitate decryption and re-encryption, even if the same keys are used.

John

John Elwell
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