From: Mark B. <mba...@ci...> - 2002-10-28 16:40:56
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hi Tony At 11:13 PM 10/28/2002 +0800, Tony Cheung wrote: >hi david and others, > >thanks for the reply. > >david a. mcgrew wrote: >>tony, >> >>>-----original message----- >>>from: srt...@li... >>>[mailto:srt...@li...]on behalf of tony cheung >>>sent: sunday, october 27, 2002 11:11 pm >>>to: srt...@li... >>>subject: [srtp-users] comparison of srtp vs. rtp over vpn >>> >>> >>>hi, >>> >>>i am new to the srtp protocol. >>> >>>i would like to know if we could use rtp over vpn to achieve the >>>security measures provided by srtp. is there any comparison out there? >> >>rtp over ipsec esp is possible, but can be quite bandwidth-inefficient due to >>the extra headers in ipsec, the esp encapsulation overhead, and the fact that >>crtp (rtp header compression) is no longer possible. for voice-over-ip, >>these >>inefficiencies are quite significant; rtp with a g.729 codec has a 20 byte >>payload that can be dwarfed by as much as 80 bytes of esp >>overhead. bandwidth >>conservation is less of an issue for video packets, though some video systems >>need to avoid encapsulation overhead so that they don't fragment (since their >>packets are right at the mtu size). >>rtp can't be run over tls or ssh, since those protocols only work for tcp >>connections. > >so rtp over ipsec vs srtp is mostly a bandwidth issue. is there any new >functionality provided by srtp? SRTP gets implemented as part of RTP. There are advantages to decrypting/authenticating at the application level rather than in the network stack for some applications, particularly consumer applications. On a multi-user system, moreover, this is the only way to provide security on a user basis. regards, Mark >thank you. > >tony cheung > >>david >> >>>thanks a lot. >>> >>>tony cheung >>> >>> >>> >>> >>>------------------------------------------------------- >>>this sf.net email is sponsored by:thinkgeek >>>welcome to geek heaven. >>>http://thinkgeek.com/sf >>>_______________________________________________ >>>srtp-users mailing list >>>srt...@li... >>>https://lists.sourceforge.net/lists/listinfo/srtp-users > > > > >------------------------------------------------------- >this sf.net email is sponsored by:thinkgeek >welcome to geek heaven. >http://thinkgeek.com/sf >_______________________________________________ >srtp-users mailing list >srt...@li... >https://lists.sourceforge.net/lists/listinfo/srtp-users |