What is a SIP Proxy Server and How Does It Work?
For many workplaces, a SIP Server – sometimes called a SIP Proxy or SIP proxy server – is the best way to facilitate communication. SIP Servers allow different SIP devices to communicate with each other.
While a SIP Proxy Server is widely used in many workplaces, many people aren’t entirely sure what they are and how they work. That’s where we come in.
This article will explain what SIP proxies are, how they work, and the benefits of using them for communications.
What is a SIP Proxy Server?
A SIP proxy server facilitates communication between two different SIP devices. In essence, the server is a channel that allows communication across devices. Any SIP device can communicate with another SIP device. Still, to do that, they need an intermediary to allow end-to-end communication, which is where the SIP Proxy Server comes in.
SIP stands for Session Initiation Protocol, which is a VoIP service that gives users all the benefits of a Public Switched Telephone Network (PSTN).
SIP contains endpoints, which can be phones, laptops, computers, and any device that uses the SIP technology. These endpoints collaborate with the SIP server to allow communication.
The SIP Server is the component that facilitates communication. In simpler terms, the server can be seen as the channel in which two SIP devices communicate. The SIP Proxy Server is responsible for placing and terminating calls between users.
When you hear about a SIP proxy server, you will also likely hear about a SIP outbound proxy. A SIP outbound proxy is a middleman between two different endpoints or SIP devices. The SIP outbound proxy is the transit point for all SIP traffic and allows for smooth and efficient VoIP functions.
What is SIP Used For?
SIP is a protocol that allows VoIP to work. SIP is a decoder that defines the different messages that are sent and received by different endpoints. SIP manages all the events of a call and can be used for voice calls, video calls, video conferences, and even instant messaging.
What are the Components of a SIP Proxy Server?
SIP Proxy servers can be viewed as a sort of “Highway Code” for SIP devices that allows communication. The SIP proxy server contains a set of rules that devices need to follow when communicating, allowing for smooth and clear messaging.
The SIP Proxy Server’s rules are responsible for making and ending calls between devices. The SIP server is the middleman that makes call routing possible.
For example, if you put a customer on hold, the server can facilitate sending a notification informing you that the customer is on hold and then redirect them according to predefined rules.
How a SIP Proxy Server Works
SIP Proxies facilitate all of the elements that make up communication between different endpoints. Understanding how SIP proxies work can be complicated, which is why many people are left confused by all the different jargon and terminologies used.
In basic terms, you can view a SIP server as a signalman. The server ensures that all the points in communication are set just right. A call can only transmit data when all the points are clear and set to the right settings, which is the job of the SIP server.
And when communication ends and a call is terminated, the SIP server is there to make sure the lines are all clear and ready for the next call.
SIP Proxy Servers can also be seen as decoders. So, any message sent to a device, no matter the format, gets received because the SIP server decodes the message.
In summary, a SIP server makes sure everything is in order when a call is made the proper actions are taken. If you need to put a customer on hold or redirect a customer when they call, the SIP server does that for you. And when a call is terminated, the server ensures that lines are clear and ready to receive the next call.
Types of SIP Proxy Servers
There are two main classification of SIP proxy servers:
- Stateless Proxy Server
- Stateful Proxy Server
Stateless Proxy Server
Stateless SIP Proxy Servers do not store any information. These servers will receive a message, forward it, then “forget” all the information or request once it has forwarded the message.
Stateful Proxy Server
The direct opposite of a stateless SIP server, a Stateful SIP Proxy Server stores information. You can view a stateful proxy server as a storage bank that tracks requests and responses so that you can easily access and use them later on.
Some people also ask whether an asterisk is a SIP proxy server and the quick answer to that question is no. Asterisk is a SIP registrar that can act as a softphone or user agent endpoint.
Benefits of SIP Proxy Servers
Here are the five key benefits of SIP proxy servers:
- A secured network
- Call forwarding made easy
- Increase dialing efficiency
- Reducing bandwidth cost
- Better performance via load-balancing
1. A secure network
A key benefit of SIP proxy servers is security. With a SIP proxy server, hackers won’t be able to tap into your network and use it for free calls and communications. Without authorization to use the service or credits to pay for the service, you won’t be allowed to use SIP calling because of the proxy server.
The server can also detect whether or not a caller has enough credits to pay for the call and if they don’t, the server will automatically disconnect them.
2. Call forwarding made easy
Another great feature of a SIP proxy is that it can automatically forward calls to SIP devices. This means that calls can ring on several different SIP phones as long as they are connected to the server.
If you’re working at a call center, this could be an amazing feature. SIP Servers allow workplaces to quickly answer inbound calls by ringing multiple different SIP phones once a call comes in.
And if you have a stateful SIP proxy, you can even save messages, calls, and different files. If you don’t get the message through the first time, you can easily access the server’s memory and forward the messages again.
3. Increased dialing efficiency
SIP proxy servers are renowned for increasing dialing efficiency. This will save your company a lot of money and improve overall employee output as less time will be spent dialing or not spent on the phone.
4. Reducing bandwidth costs
Making use of a SIP proxy server is a great method for reducing your overall bandwidth costs. The SIP proxy server allows for long-distance and international calls at a significantly lower cost. Aside from that, you can also exchange data as well as text and multimedia.
5. Better performance via load-balancing
When using a SIP proxy server, the overall dialing performance will be improved thanks to load-balancing. This means that no single person or software will be overwhelmed during peak time.
Final Thoughts on SIP Proxy Servers
In basic terms, a SIP proxy server allows you to make smooth calls with minimal interference. It facilitates communication between different SIP devices ensuring that your VoIP functions properly and efficiently.
With a SIP proxy server, you can make the most of VoIP while simultaneously cutting costs, just like SIP trunking, and growing your business.