Subject: [Sip] Comments on section 19 Transport in bis-07

From: "Hisham Khartabil" <[email-masked]>
Date: Fri, 15 Feb 2002 18:35:38 +0200

Hi,

I decided to divide my comments into sections, the earlier email I sent
seemed to be too long.

Line numbers refer to the pdf version.

Section 19.1.2
- line 3634: "the response MUST be rejected". Better if it says "the
response MUST be silently discarded".

- lines 3635 to 3639: talks about how the response should be passed to the
core if no client transaction is found. Is this a potential DoS attack?

Section 19.2.2
- line 3668: "If that connection is no longer open, the server MAY open a
connection to the IP address in the received parameter,". MAY? what other
options does the server have if it longer has the connection open? I think
this MAY should be a MUST.

- line 3671: should SSL be SCTP instead?

- line 3680: "If this fails, e.g., elicits an ICMP “port unreachable”
response, send the response to the address in the “sent-by” parameter." Is
sending the response to the address in the "sent-by" a MUST or SHOULD?.
Maybe better read "If this fails, e.g., elicits an ICMP “port unreachable”
response, the response MUST (SHOULD) be to the address in the “sent-by”
parameter.".

Section 19.3
- line 3689: "If the message is a response, it MUST be discarded. If its a
request, the element SHOULD generate a 400 class response". which response
exactly? the 400 itself? if so, the word "class" should be removed from that
sentence and (Bad Request) should be added.

Regards,
Hisham Khartabil

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From: Robert Sparks <[email-masked]>
Date: Sun, 17 Feb 2002 23:16:16 -0600

These are addressed or are being tracked.
One comment inline.

RjS

> core if no client transaction is found. Is this a potential DoS attack?

In and of itself, no. If the core unduly creates state based on these
messages, maybe. The sections on the cores discuss these cases. Proxies
statelessly forward the responses for example.

> - line 3680: "If this fails, e.g., elicits an ICMP "port unreachable"
> response, send the response to the address in the "sent-by" parameter." Is
> Maybe better read "If this fails, e.g., elicits an ICMP "port unreachable"
> response, the response MUST (SHOULD) be to the address in the "sent-by"
> parameter.".
> 
> Section 19.3