[Asterisk-Users] INBAND DTMF G729 ASTERISK

[Joshua Colp]

It depends really. There's about 3 different ways to send DTMF with SIP. One
is inband, as audio. Another is rfc2833, which is not as audio - but still
goes via the RTP stream as separate packets. The last one is info, which
sends it over the control stream as SIP packets.

- Joshua Colp.


On 6/25/05 1:09 PM, "Tzafrir Cohen" <tzafrir at cohens.org.il> wrote:

> On Fri, Jun 24, 2005 at 11:57:17AM -0400, Julio Arruda wrote:
> 
>> 2- Out-of-band is as safe/unsafe as having the conversation recorded,
>> including pin, by the hacker, if no encrypted voice path is being used.
> 
> I haven't given much thought to this earlier, so I hope the following is
> not total crap:
> 
> in-band is in the data and out-of-band goes in the control stream of
> SIP, right? If so, those two may be on different pathes, and it is also
> possible to encrypt one and not the other.
> 
> I figure it would make sense to encrypt the control stream alone, and
> not waste costly resources on the data stream. FTP/Kerberos and (in a
> way) telnet/Kerberos are similar.
> 
> /me wander off thinking about the impact of an attacker with just the
> ability to drop arbitrary packets from a VOIP connection.