To sip phone is a little doubt, at the two end connection is established, through the server, so when two side began to talk on the phone, after the data through the server? For example, A, B is to talk on the phone, the two end of the C is the server, A call B, A C first to send the Invite, C to A back to Trying, C send the Invite to B... After A series of communication, you can speak A and B, then A say "hello", this period of voice sent to B will be sent to the server first?
//analysis is not myself, but not sure

CodePudding user response:

Voice the media stream can be through the server, also can not through the server, this should see you SIP server and its configuration used in the situation,
Media flow through the server, can do the recording, code conversion, the business such as monitoring,
Media stream without server, can reduce the pressure of the server, show little delay, more efficient,

CodePudding user response:

Signaling through server forwarding is reasonable, signaling the bandwidth is very small,
As the upstairs said, media (RTP package) can after a public server forwarding, benefit is the ability to solve the problem of a lot of NAT penetration, the downside is that the server has enough bandwidth;
If you don't after server forwarding media, that is what is called a peer-to-peer (p2p), if the two end not in a local area network (LAN), need to solve the problem of NAT, etc,

CodePudding user response:

Sip is meant to initiate A conversation, his role is to negotiate the media, also is to let A knows B media information (contain A send media where B where is the answer, media encoding formats, etc.), let B know A media information, these all negotiations, sip session is established, can talk on the phone, the RTP data is sent to develop in the process of negotiation, if negotiation result is sent directly to B, B is sent directly to A, that is end2end, if you need A media server, the result of the negotiation is A and B are sent to the media server, media server forwarding again

CodePudding user response:

Streaming media is the main benefit of A server can realize the VOIP calls between different networks, such as the network is not between A and B, but A and B, respectively, and the server can be Shared, after server relay can be achieved AB streaming media interaction

CodePudding user response:

Media data can not through the server, if you can direct to send and receive data

CodePudding user response:

This see you choose what kind of server, 3 cx server can specify an extension of the RTP calls through/not through a server.

https://bbs.speedytel.com/forums/topic/671/

CodePudding user response:

Sip message interaction through a proxy server, and then after the call to establish, is an end-to-end connection, also is the RTP stream, belong to the multimedia stream, is not through the server, image is the sip standard document RFC2316 screenshot, you can see, the connection is established after the specific communication is not through the server, can also be caught see, , the building Lord if you want to study or to the sip standard document,