Outbound Proxy and Proxy Server for SIP

Hi, what is the difference between an outbound proxy and a proxy server for SIP?

Why are there 2 fields required for connection sometimes?

I'm asking because my voip provider has provided me sip trunking 20 lines. They have said the outbound proxy needs to be a certain proxy, then the proxy server to be another one.

It seems the calls have issues if the outbound proxy is set differently or not set at all. I experienced call drop outs and difficulty in registration.

Can the provider do that?
bineleAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

yarwellCommented:
the outbound proxy is usually one close to you for example on your LAN and it handles all your SIP requests. It can be used for policing and charging purposes.

It is itself a proxy server. Proxy servers in general pass SIP requests on and return responses in a way like SIP routers. HTH.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
bineleAuthor Commented:
Both of them are not in the LAN.  So I guess the reason why the Outbound Proxy is used in this instance is for policing purposes. I know for a fact that the number of SIP messages to the Outbound Proxy is being controlled and if there's too many, the IP will be blocked for a good ten minutes.

Also, one thing I noticed is that this provider gives back an Unauthorised 404 each time the first invite goes.

Any idea what this is?
yarwellCommented:
Might be greylisting, other than that no idea.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Telecommunications

From novice to tech pro — start learning today.