We help IT Professionals succeed at work.
Get Started

RTP Problem with Firewall

Last Modified: 2014-12-04
I saw the following statement in a tutorial on SIP, RTP firewall n NAT. I am unable to understand it - '

When there is a firewall in between the SIP signaling request response is allowed. But there is a problem during RTP.  During RTP the data will be able to go through firewall to User agent but data from user agent won’t be able to reach the other side of the firewall as the firewall does not have information about port to which the User Agent is sending data.

What i dont understand here is that
1) Why the firewall needs to have prior information about the port to which the User Agent will send data ?
why cant it allow data transfer to the port.
2) If there is a problem with RTP transfer when there is a firewall, why is there no problem during SIP signalling.

Also please let me know any good resources or tools to study SIP (session initiation protocol) and RTP, firewalls
Watch Question
Distinguished Expert 2018
This problem has been solved!
Unlock 1 Answer and 10 Comments.
See Answer
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE