On Thu, Feb 25, 2010 at 7:35 PM, Aaron Clauson <[email protected]> wrote:
> > Does anyone have a good idea about how widely SIP-over-TCP and SIP- > > over-TLS > > is used, compared to SIP-over-UDP, in the real world? > > > > (oops, meant this for the list) > > When I implemented SIP over TLS and asked my users (I run a SIP aggregator > service with over 1000 different SIP providers being used) if any knew of a > SIP provider that supported sips and I didn't get a single response. > > I found one eventually, snom.com, but I think it's fairly safe bet to say > there are not too many public SIP services that support TLS, TCP support is > also fairly low, at a guess maybe 10 or 20%. I've never come across one > that > doesn't support UDP. > > One reason TLS and TCP are not as popular on high volume public services is > the connections take significantly more resources to maintain compared to > UDP. > We have actually measured the impact of TLS cost on SIP server performance using the OpenSIPS server on an Linux-based intel platform. Between TCP and TLS, we see a performance reduction around a factor of two. But if we compare the simplest UDP configuration with the most sophisticated TLS configuration, namely multiple-connection-based, and with TLS mutual authentication as well as SIP proxy authentication enabled, there could be a slowdown factor of nearly 20. The technical report is available at the following link: The Impact of TLS on SIP Server Performance https://mice.cs.columbia.edu/getTechreport.php?techreportID=602&format=pdf&; We have also studied SIP scalability over TCP: One Server Per City: Using TCP for Very Large SIP Servers. https://mice.cs.columbia.edu/getTechreport.php?techreportID=507 and The impact of SCTP on Server Scalability and Performance" https://mice.cs.columbia.edu/getTechreport.php?techreportID=510 Thanks Charles > Aaron > > > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
