[Asterisk-Users] Asterisk + BudgeTone (behind NAT)

[John Todd]

At 9:17 PM -0500 1/23/04, Owen Kelso wrote:
>I've been following up on my problem, which I previously described as:
>
>>  I've concluded that the Netgear router (FVS318) performing the NAT is
>>  corrupting the outgoing RTP packets.  Traces confirmed that the BudgeTone
>>  is sending them out with a UDP checksum of 0 but the next hop after the
>>  Netgear router they are set to a non-zero value (an incorrect one).
>>  Asterisk is never even seeing the packets because the kernel is
>>  recognizing them as corrupt and dropping them, hence the recvfrom()
>>  "Resource temporarily unavailable" errors in rtp.c.
>
>Here is Netgear's response:
>
>---------------------------- Original Message ----------------------------
>Subject: RE: Webform contact request [#<removed>]
>From:    support at esupport.netgear.com
>Date:    Fri, January 23, 2004 7:36 pm
>To:      <removed>
>--------------------------------------------------------------------------
>
>
>SIP VOIP phones do not work with netgear routers. The router will always
>set a value in the checksum.
>
>
>Regards
>
><removed>
>Netgear Support
>support at esupport.netgear.com
>
>Please help us serve you better by clicking here
>mailto:support at netgear.com?subject=Feedback_us if you would like to
>provide any other valuable feedback.  (Note: this feedback is not sent to
>an agent so you will not receive a reply.)
>
>--------------------------------------------------------------------------
>
>Not exactly what I call stellar customer service!
>
>I realize this may not be the best solution -- actually, it's probably not
>even a good solution -- but has anyone experimented with using the Linux
>SO_NO_CHECK setsockopt() option?  It looks like it could be used to ignore
>the checksums for the RTP packets.
>
>Owen

Time to dump the Netgear router.  That's an unacceptable answer for a 
router vendor to say "Oh, well, for this MAJOR protocol we're going 
to simply corrupt those packets so they're unusable."  What!?

JT