For many up-and-coming businesses, every decision, every resource, and every minute can count–especially with phone plans. As startups look to the latest, most flexible, and most affordable technologies to help them grow, many have found a better way to do their calling—with a server that they never have to touch.
SIP servers, which run the Session Initiation Protocol (SIP), enable VoIP-based communication like online calls and chats.
In general, the term SIP server refers to any server that performs SIP-based call processing. You may have heard this term used interchangeably with SIP proxy, but they’re not quite the same.
A SIP proxy is a specific type of SIP server that routes SIP requests to a user’s current location, in addition to authenticating and authorizing users for services, implementing call-routing policies, and providing users with features such as call-waiting and call-forwarding. Thus, all SIP proxies are SIP servers, but not all SIP servers are SIP proxies.
But back to the topic at hand. The reason why startups are choosing SIP servers they never touch is because of modern, hosted phone systems. These off-site solutions, managed by seasoned professionals, provide the advanced communication capabilities of a SIP server without the headaches of setup, maintenance, or even physical equipment.
What Does a SIP Server Do?
SIP Servers are part of the system that makes Voice over Internet Protocol (VoIP) calling possible. It’s through these servers that SIP requests and responses are sent.
If you’re used to old-school PBX phone systems that rely on copper wires and switchboards, you’ll also probably know that a telephone operator used to route calls manually. An IP-PBX, or Internet Protocol Private Branch Exchange, is basically a modern telephone switchboard for your business—but instead of traditional phone lines, it uses the internet to manage your calls.
The bridge between your IP-PBX and the rest of the world is something called SIP trunking. It’s like the ramp onto the highway that connects your business’s phone system to the internet, allowing you to make and receive calls from anywhere in the world.
Thus, instead of using old copper wires to make a call, you can use your internet connection via SIP trunking to connect to someone else’s phone system—be it a traditional landline, a mobile phone, or another IP-PBX. This process of making voice calls over the internet is known as VoIP calling.
Different kinds of SIP servers are needed to make this system work. Each server plays a different role in a SIP network, helping to manage and process SIP calls. Some important servers are:
- SIP Registrar: This server is like a secretary, keeping track of where everyone is located (including the IP address and port number of a user’s device). The SIP Registrar is responsible for accepting REGISTER requests. It records these details so it knows where to direct calls.
- Location Server: This server uses the info collected by the SIP Registrar to route calls correctly. It’s like a GPS for your calls, ensuring they reach the right destination.
- Redirect Server: This server is like a traffic cop directing you to another route—but it’s not involved in the actual connection or conversation. Upon receiving a request, this server tells the client to contact a different end system or server, but it doesn’t initiate a connection or handle further communication.
Additionally, SIP servers can be classified as stateless or stateful based on how they handle transactions. It’s good to know the differences between these types so you can judge them for your startup’s needs.
Stateless SIP Server
This server is like a forgetful friend. It processes requests and responses, but it doesn’t remember anything once the conversation is over. It’s efficient because it uses less memory since it always starts with a clean slate, but it can’t re-send messages if there’s a network issue.
Stateless servers are often used in simpler networks where there is less need for reliability, or in cases where network performance and speed are top priorities.
Stateful SIP Server
On the other hand, the stateful SIP server is like an elephant that never forgets. This means it keeps a record of all active transactions, allowing it to resend messages if necessary.
Employing a stateful server can ensure more reliability in the communication process, which is crucial for complex or high-stakes networks where the cost of a failed or lost transaction is high. That said, this comes with higher memory demands, so it may not be the best choice if system resources are limited.
All in all, if speed and efficiency are your top priorities—and you’re willing to accept the risk of occasional messages getting lost—then a Stateless SIP server could be the right choice. Meanwhile, if reliability and thorough record-keeping are more critical, you might opt for a Stateful SIP server instead.
SIP Servers and Security
Unless well-protected, most things that connect to the internet run the risk of security breaches, malware, and the like. This goes for VoIP sessions and the SIP servers that deliver them, too.
Fortunately, SIP servers can be secured by implementing strong authentication methods such as robust passwords and encryption. These methods can prevent hackers from accessing your phone system, meaning only authorized users with proper credentials can make or receive calls.
In addition to enforcing authentication, SIP servers can enable remote workers to use a company’s VoIP communication service safely and securely, just as if they were in the office. This ensures that all communication remains safe and encrypted, protecting sensitive information from falling into the wrong hands.
The reason why you’ll want to have a secured server is because of the potential costs of a compromised VoIP service. For instance, if hackers gain unauthorized access to your phone system, they can make long-distance or premium-rate calls that you’ll have to pay for. Not only could this cause substantial losses, but it could also damage your reputation and even lead to a loss of customer trust and potential business opportunities.
All of these risks present yet another compelling case for why a startup might choose a hosted server with its own security measures.
Benefits and Tradeoffs of a Hosted SIP Server
Since communication is the lifeblood of any business, having a reliable and cost-effective phone system is essential. That said, there are two ways to manage these communications: one, with an in-house SIP server, or two, with a cloud-based, hosted solution.
A hosted phone system is a managed service that operates your phone calling features over an internet connection. In other words, your phone system lives in the cloud, managed by a provider somewhere else, and you access it from your office or even on the go.
The many benefits of a hosted SIP server include:
- Cost-effectiveness: Opting for a hosted SIP server eliminates the need for expensive infrastructure, as the service provider takes care of hardware, maintenance, and upgrades. This allows startups to allocate their resources to other critical business areas.
- Scalability and flexibility: Hosted SIP servers offer easy scalability, meaning you can add or remove users as your business grows or contracts. Additionally, these servers support a wide range of devices and protocols, allowing for seamless integration with existing communication systems.
- Heightened security: SIP servers have default security measures such as encryption, firewalls, and intrusion detection systems to protect data from unauthorized access and potential cyber threats. Plus, service providers normally update their security protocols to stay ahead of emerging risks.
- Reliability and disaster recovery: Hosted SIP servers are designed to offer high availability and redundancy. Service providers often have multiple data centers, ensuring your communication remains uninterrupted, even during a power outage or hardware failure.
Now, of course, it’s not all sunshine and rainbows. With a hosted system, you’re putting a lot of trust in your service provider. That means if their system goes down, so does yours.
Likewise, relying on a third-party service provider also means you have less control over your communication infrastructure. You have to accept the hosted solution’s settings, which are often broad or narrow enough to accommodate a fixed set of business needs, not just yours.
For smaller startups, this method may work. However, enterprise clients may need more customized settings, which is where the cost could grow. The pricing could also surge based on the number of locations and employees utilizing the system—and a high call volume could make a hosted service progressively more expensive over time.
Thus, if you’re running a larger business with more substantial resources—or if you have specific requirements that need a customized solution—then managing your own SIP server and related systems may provide the control and customization you need.
However, smaller businesses and those without dedicated IT staff members can readily benefit from the flexibility and scalability of a hosted solution.
At the end of the day, it’s all about finding the right balance for your business by weighing the costs, the resources, the potential risks, and the amount of control you want. Finding the right fit could mean a smoother, more effective communication system for your company.