SBC is a rather arbitrary term referring to a bunch of different functions. Typically an SBC is a B2BUA, RTP media-proxy, stateful firewall, QoS/policer, NAT traverser and a transcoder, but this is not always the case. Some vendors stick on the name SBC, and it just performs SIP ALG functionality.
I typically just call them B2BUAs, and will specify whether they have additional functionality, because the term SBC really doesn't mean anything when there is no standard as to what functionality a device needs to support in order to earn the name. SBCs typically follow a bunch of separate standards, without implementing any "magic" outside of what a certain standard allows. IE: In RFC 3261, there is no mandate on what a B2BUA has to do when it translates signals from a dialog facing one endpoint to a dialog facing another. Removing/Adding/Changing header values is both allowed, and maybe even expected. Joel Gerber Network Specialist Network Operations Eastlink E: joel.ger...@corp.eastlink.ca T: 519.786.1241 -----Original Message----- From: Paul Kyzivat [mailto:pkyzi...@alum.mit.edu] Sent: July-18-13 11:11 AM To: ikuzar RABE Cc: sip-implementors@lists.cs.columbia.edu Subject: Re: [Sip-implementors] RTP flow's route follows SIP flow's route ... Then stop calling it a *proxy*! It is an SBC. Thanks, Paul On 7/18/13 6:28 AM, ikuzar RABE wrote: > Ok thanks for your responses, > There is indeed an RTP proxy within the sip proxy... and it works as > you described above. > > > 2013/7/17 Paul Kyzivat <pkyzi...@alum.mit.edu > <mailto:pkyzi...@alum.mit.edu>> > > As others have noted, for this to happen the "proxy" (proxies?) needs to > modify the SDP to cause this to happen. If it does this it has violated > the rules for a proxy. Devices that do this are typically called Session > Border Controllers. It is very common. There are both advantages and > disadvantages to doing this. > > Thanks, > Paul > > On 7/17/13 5:29 AM, ikuzar RABE wrote: > > Hi all, > > > > I saw a RTP flow which is not directly established between UAC > and UAS but > > goes through a SIP proxy ... > > > > Is there any information in SIP message exchange producing this > situation ? > > > > Thanks for your help, > > > > ikuzar > > _______________________________________________ > > Sip-implementors mailing list > > Sip-implementors@lists.cs.columbia.edu > <mailto:Sip-implementors@lists.cs.columbia.edu> > > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > <mailto:Sip-implementors@lists.cs.columbia.edu> > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
