[Asterisk-Security] adding a TCP support to Asterisk ....

[Enzo Michelangeli]

----- Original Message ----- 
From: "Bret McDanel" <bret at mcdanel.com>
Sent: Friday, July 14, 2006 9:05 PM

> On Fri, 2006-07-14 at 05:49 -0700, vivek relan wrote:
>> Hi everybody,
>>
>>                 If we add the TCP support to the Asterisk, will it
>> provide same voice quality and what will be the impact on delay,
>> security and performance ?
>>
>>                 Waiting for the suggestion !!!
>>
>
> If you have a dropped packet it will cause horrible delay until that
> packet is retransmitted.  Basically its not advisable for things that
> can tolerate some packet loss and require 'real time' processing.

Well, TCP should be used as transport for the SIP signalling, rather than 
for the media data. The main advantage of using TCP is that TLS becomes 
immediately available as security layer ("sips" URI's) so the session key 
used to secure the media data with SRTP 
(http://srtp.sourceforge.net/srtp.html ) can be easily transmitted as 
cleartext (encapsulated in TLS) rather than having to rely on awkward 
content encryption schemes such as S/MIME.

Of course, this all applies to SIP sessions, not IAX2.

Enzo