24 Apr
2008
24 Apr
'08
9:58 p.m.
Hi,
By the timeout implementation in now more secure the support of the NAT
IP change. To change the Caller/Called address the mediaproxy waits for
two seconds that the Caller/Called doesn't send any rtp/rtcp packet and
checking the SSRC. This change was tested and in production working
well.
Also I found a bug in the asymmetric RTP UA support. This file contains
the fix of the bug, the solution to the bug is very simple. How can I do
to report the bug and the solution?
Regards
"Gonzalo J. Sambucaro"
<gonzalo.sambucaro(a)mslc.com.ar> writes:
--
Gonzalo J. Sambucaro
Ingeniería de Software
Tel: +54-341-4230504
MSLC
gonzalo.sambucaro(a)mslc.com.ar
www.mslc.com.ar
Ocampo y Esmeralda - Vivero de Empresas de Base Tecnológica
Ciudad Universitaria Rosario UNR, CCT CONICET
Rosario - Santa Fé - Argentina
[...]
1) When the first rtp packet of a source arrives, save the SSRC field in
the MP.
- Save the SSRC of the caller.
- Save the SSRC of the called.
2) If arrives a rtp packet with unknown source IP but with the same SSRC
field of some of the two streams, updates the binding (with the new IP
detected) between the caller and the MP or between the called and the MP
according to the field SSRC previously saved.
An attacker would have to guess/sniff the SSRC and then could take over
the rtp session? (maybe could be fixed by only allowing to take over
after some timeout)
On the other hand if he can sniff ...