top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

SIP: Does all the SIP control messages passes through SIP proxy-server or only a subset of SIP messages?

+1 vote
978 views

In one of the articles it was mentioned "BYE" SIP message routes end to end and by pass the SIP proxy server. What is it mean ? and when SIP proxy servers release the resources that was reserved during the session establishment ?

posted Aug 14, 2016 by Vikram Singh

Share this question
Facebook Share Button Twitter Share Button LinkedIn Share Button

2 Answers

+1 vote

During establishment of a dialog between two user agents, multiple proxy server may involve. But once the session/dialog establishes between end user agents, SIP signalling messages can be forwarded directly.
For example : There are two user agents named UA1 and UA2 and UA1 sends INVITE message to UA2. In a typical case, this INVITE message reaches from UA1 to UA2 by using proxy servers PS1, PS2, PS3 and PS4. UA1 has connection with PS1 and UA2 has connection with PS4. After establishing a dialog between these two user agents, message will follow the following path:
U1 <--------> PS1 <--------------> PS4 <-------------------> UA2

ACK, one of the SIP message uses the above path.

answer Aug 17, 2016 by Harshita
0 votes

SIP SERVER..

answer Aug 25, 2016 by Jitendra Jain
Will you like to describe more about your answer?
commented Aug 26, 2016 by Salil Agrawal
Similar Questions
+1 vote
SIP: In what cases or scenarios, an user agent can send INVITE within an already established Dialog between UAC and UAS?

As we know, when a session is established between two user agents i.e. UAC (User Agent Client) and UAS (User Agent Server), known as Dialog in SIP terminology. I read that a SIP user agent client can trigger INVITE message towards user agent server in an already established session. This scenario is known as "re-invite" but I am unable to think the case in which it happens.

0 votes
SIP: When does proxy server initiate authentication/authorization for the received INVITE request ?

While going through rfc 3665 , I stopped where proxy server was sending 407 to originator of INVITE request message.
I want to know in what cases/scenarios, proxy server does this.

+2 votes
LTE: Why a separate default bearer is required to exchange SIP signalling messages between UE and IMS network ?

Is it mandatory to establish a separate default bearer to exchange IMS signaling messages between UE and IMS network nodes ? Can't internet default bearer be used for the same ?

...