[asterisk-dev] [Code Review]: Lightweight NAT Support

[Joshua Colp]

> On Feb. 21, 2012, 8:35 a.m., Simon Perreault wrote:
> > I have two questions...
> > 
> > 
> > 1. CRLF keep-alives are supported only for connection-oriented transports. Not UDP. Excerpt from RFC 5626:
> > 
> > 4.4.1. Keep-Alive with CRLF
> > 
> >    This approach MUST only be used with connection oriented transports
> >    such as TCP or SCTP; it MUST NOT be used with connection-less
> >    transports such as UDP.
> > 
> > This is because of RFC 3261 section 7.5. Excerpt:
> > 
> >    Implementations processing SIP messages over stream-oriented
> >    transports MUST ignore any CRLF appearing before the start-line
> >    [H4.1].
> > 
> > A CRLF transported over UDP is just plain wrong. It is not valid SIP.
> > 
> > So, question: did I miss something? Did I not understand what you're sending over UDP?
> > 
> > 
> > 2. If Asterisk is talking over TCP or TLS to a UA that supports RFC 5626, that UA would echo the CRLF back to Asterisk. Is Asterisk prepared to handle that?

1. I was under the impression that this was also for UDP, at least that is what the discussion I was in on led to. Unfortunately I wasn't at the Asterisk dev cons so I don't know what was discussed there about it. I can say though that other clients do use CRLFs for this purpose, even on UDP transports.

2. Yes. We will accept CRLF over any transport, that was done long long ago.


- Joshua


-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviewboard.asterisk.org/r/1756/#review5565
-----------------------------------------------------------


On Feb. 21, 2012, 7:26 a.m., Joshua Colp wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviewboard.asterisk.org/r/1756/
> -----------------------------------------------------------
> 
> (Updated Feb. 21, 2012, 7:26 a.m.)
> 
> 
> Review request for Asterisk Developers.
> 
> 
> Summary
> -------
> 
> This patch implements extremely lightweight NAT support, specifically sending a CRLF at a defined interval to keep the NAT mapping open. It does not use this mechanism to determine if the remote server is available or not, that is the trade off.
> 
> 
> Diffs
> -----
> 
>   /trunk/channels/chan_sip.c 355996 
>   /trunk/channels/sip/include/sip.h 355996 
>   /trunk/configs/sip.conf.sample 355996 
> 
> Diff: https://reviewboard.asterisk.org/r/1756/diff
> 
> 
> Testing
> -------
> 
> Confirmed packet is sent at default interval as well as configured interval. Also wrote testsuite test which will be in another review.
> 
> 
> Thanks,
> 
> Joshua
> 
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.digium.com/pipermail/asterisk-dev/attachments/20120221/6ebaed46/attachment.htm>